| Survey - What Size Motor for 9"
Southbend (Feb 18, 2001) |
Problems starting lathe
(Aug 15, 2003) |
| Need a Motor (Feb 26,
2002) |
3 phase? (Aug 25, 2003) |
| 3 phase motor vs. single phase
(May 3, 2002) |
Power King motor (Sep
10, 2003) |
| 10" Toolroom, 110/220
(Apr 22, 2002) |
Electric Motor Frame Sizes
(Jan 5, 2004) |
| 220 (Jul 24, 2002) |
Motor size limit for 11" lathe
(Jan 8, 2004) |
| Three phase 440/220
(Nov 16, 2002) |
16" motor horsepower
(Jan 9, 2004) |
| Motor Replacement?
(Dec
1, 2002) |
Maximum Power for Heavy 10?
(Mar 8, 2004) |
| Relocating the motor drive on a
9" (Dec 6, 2002) |
New motor HP and RPM maximum
(Apr 13, 2004) |
| Bodine motor data
(Mar 13, 2003) |
SB 9 replacement motor help
(May 5, 2004) |
| New motor for SB 9" A
(Mar 5, 2003) |
9 in Motor Selection
(Jul 7, 2004) |
| Electric motor (May 3,
2003) |
Heavy 10 motor replacement
(Jul 27, 2004) |
| SB 9 motor (May 7, 2003) |
Motor Choice for 13" SB? (Jul 30, 2004) |
| DC Motor conversion (Jun
10, 2003) |
Heavy 10 Motor Change? (Aug 12, 2004) |
| Lathe motor base/mount
(Jul 20, 2003) |
South Bend 9A Motor Voltages (Nov 16, 2004) |
| S/B Motor size (Jul 29,
2003) |
Model 9A motor replacement (Nov 29, 2004) |
| Motor recommendations needed
(Jul 31, 2003) |
New
Motor? (Dec 14, 2004) |
| Motor - Single or 3-phase?
(Aug 5, 2003) |
Motors/controllers: too many choices (Feb 11, 2005) |
| |
| Survey - What Size Motor for 9"
Southbend |
| I would like to
here from all of you 9" guys on what size electric motor you are
using. I have seen 1/4HP to 1HP used. I have a spare 1/3HP and I am
not sure if it is heavy enough to use. Jim
(233) |
| For over 20 years I used the same
old 1/4hp washing machine motor that came with the machine when I
bought it. I recently replaced it with a new 1/2 hp capacitor start
and run 1750rpm from HF and it fits a little tight but works.
Actually I could jump the belt off the pulley as easy with the old
motor as the new one. The rear of the motor shows fairly well in
this picture. It fills the area very well and I would not consider
putting a larger one in there. JWE (241) |
| I picked up a used
3/4 HP 1P G.E. 1150 RPM cap-start/cap-run motor to use on my 9". I
chose the lower RPM since I'll be making the pulleys for the
motor/counter shaft. (mine had non-standard pulleys. No real idea
how 3/4 HP will do yet, but it should be okay since its an
American-made motor. I've got it wired for 220, of course. Paul R.
(247) |
| I just checked my 9" and it is
running with a 1/3hp 110v motor and I have had no problems at all.
Yesterday I talked to South Bend and they said that even the Heavy
10 was shipped out with only a 1/2hp motor, so you should be able to
use a 1/3hp with no problems. Karl (263) |
| Need a Motor
|
| I need a new Motor for my 9x36 South Bend Lathe. It now has a
large 1/4 horse Westinghouse With B145K frame with a 5/8's inch
drive shaft 3/16inch key Instant reverse. Dose any body know what
the motor number would be in the Grainger catalog. I would like to
stay a 1/2 Horse or less (1/3or 1/4). I can make a adaptor plate to
mount it to the frame if needed. Or dose any one have a better idea
on where I can get a motor. Chet (3412) |
| Have you tried a
local motor shop? Often they have used motors that they have gone
through for cheap. you can call Grainger and they will cross
reference the motor. However, it sounds like the motor you have is
not the right size. FWIW: I called Southbend and talked to I think
randy, and he said that to replace it with a 1/2 horse motor, 5/8
shaft, shaft length ??? 1/2 horse max otherwise you will toast the
headstock bearings. Sounds like decent enough advise. I bought a
lesson from the local motor shop. I made the mistake of getting
plain 56 type frame, welded to the base of the motor. Was a royal
pain to get in because of clearance issues to get at the bolts.
Price was $120, about same as Grainger, plus I got the support
locally. I don't know the NEMA mount number, but get the kind that
has a separate base from the motor and clamps the motor at the ends
with collars. makes life now and hereafter MUCH easier. dennis (3413) |
| Why
would a larger motor hurt the headstock bearings? I have a 3/4 horse
on mine (what I had on hand at the time) and I don't seem to have
any problems with bearing heat. Frank (3414) |
| Dumpster diving is
a good source for working motors, old dryers, washing machines etc
often are tossed when the motor is still good, but other parts have
worn out. Don't try a vacuum cleaner motor though as they are
usually much too fast for lathe or machine use. John (3428) |
| Dryer motors
probably even have a decent mount to go with them (I see a LOT of
them in a day) Very seldom do dryer motors ever burn out. Maytag's
rule! Matt (3429) |
| My little 9" has a
1/4 h.p. motor on it and the other night I decided to see how heavy
a cut I could take with it. After playing with the feed rate and
sharpening the tool just right, I was able to take a .200" cut off a
three inch diameter piece of mild steel! the belts never slipped and
I thought about trying for more but then thought ...... why? the
feed was fairly slow and the spindle speed was the slowest you can
go with out using back gear. These little lathe are tough and will
do the lions share of the work if you take your time and set them up
right. Charles (3430) |
| 3 phase motor
vs. single phase |
| I have a new
10k (well, 1954 new). It currently has the 220v 3 phase 1/2 horse
motor. I've found the following on eBay and I'm wondering if this
would be a 1:1 replacement. I know I may have to work on re-drilling
some holes... "South Bend 9" Lathe single phase 1/2 Hp motor
(reversible), Dayton capacitor start. Works with 9", 10k, heavy 10
lathes. Motor is 110v, good used working condition. If you need the
Forward/Reverse Control see my other auctions." Steve (4178) |
| That motor was
originally purchased from Granger supply. Dayton is their trade name
just like Craftsman belongs to Sears. Check on the price with
Granger before you buy a used motor. You might find very little
difference. There's nothing like a brand new motor. RC (4179) |
| Steve, keep the 3
phase motor and consider powering it with a VFD. It will run your 3
phase motor off of single phase 220 and provide a host of other
features such as variable speed. Smoother drive too. Do a search on
VFD's they are available as surplus. Steve (4181) |
| Steve, Sorry, while
I'm handy on the computer and should be able to find the info, can
you help me out with a bit more info? I'm guessing this means
"variable frequency drive", but I don't know what else I'm looking
for. Can you help me out with some more details? I've had an offer
from a guy a couple hours away to help me build a rotary phase
converter, but I know so little about this stuff... AND, I spent all
my cash (well, all that the wife will let me spend) on the lathe so
I'm trying to keep this piece cheap if possible. (4182) |
| I recently bought a
VFD (variable frequency drive) from eBay, for $100. This drive was
for up to a 1hp motor, so it is larger than the one that you would
need (probably 1/2hp or 3/4 hp) for a Heavy 10 lathe. Here is the
link to an auction for the same drive that I bought from these
people: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem
item=1727711565 If you want to go the cheaper route and just switch
to a single phase motor, then I think that just about any US-made
used 1/2hp or 3/4 hp motor of the right size should be OK. The
wiring diagram for reversing the direction of the motor should be on
a plate on the motor housing. The auction that was posted on this
group for a "south bend lathe motor" was not particularly special...
There are several classes of enclosures for electric motors. I think
that the most common is "TEFC", which stands for totally enclosed
fan cooled. This should be OK for an under-the-cabinet lathe motor.
Motors for harsher environments might be called "TENV" (totally
enclosed non-ventilated). Another one is ODP (open drip proof),
which also should be OK for a lathe. There are specific dimensions
for sizing with "NEMA" numbers that correspond to particular
dimensions. Information can be found on the www by doing a search on
www.google.com , with phrases like, "electric motor", or "variable
frequency drive". You should be able to find a good used 1/2 hp or
3/4 hp motor, 1725 rpm, from a motor repair place, a used tool
store, or a garage sale, for $20 or so. Jon (4183) |
| Steve, Try this
site:
http://www.chaski.org/homemachinist Run a search on the archives with the letters VFD (variable frequency drive). A VFD
will do a lot more for you than a rotary converter ever will. There
NOT power hogs and your 3 Phase motor will actually give you a
better finish on your work.( It doesn't tramp like a single phase
motor does. Also check out the practical machinist site. A lot of
VFD info here. Its true 3 phase from single phase power. Steve
(4188) |
| Steve, Here is the
Practical Scoop! http://www.practicalmachinist.com Steve (4189) |
| 10" Toolroom,
110/220 |
| In
the process of buying 10" toolroom. It is currently wired for 110
volts. Would there be any advantage to rewire for 220 single phase?
(In my home shop, don't have 3ph. available) and don't want to mess
w/converter. Darren (4020) |
| Not much to be
gained by rewiring for 220 for a small induction motor (1.5HP or
less). I do like running all my big stationary power tools on 220,
however. They're more efficient, faster starting, and the lights
don't dim with 220. I currently have my 10" table saw, 12" radial
arm saw and my 9" South Bend running 220. I still need to run 220
power for my mill/drill (2HP) and Delta wood lathe (1.5HP). Another
reason to run 220 is if you ever wanted to put an inverter drive on
the lathe. That's what I did and I love it. Paul R.
(4021) |
| The only reasons
you may want to think about rewiring
would be if you need a bigger motor that is only 200, or if you have
a problem that your existing (shop) wiring cannot handle the load on
a 110 circuit. if you need a separate circuit for the machine (
always a good idea in my book) then it's only a little more
expensive to install it for 220 but there is often no real advantage
to doing it that way. if the machine makes the lights blink or
causes other power disturbances when you start it or when loading it
up, or has very poor power under loading, then you need a separate
circuit. if it's on a circuit of its own and still does that, then
going to 220 may help by reducing the load on one phase, then again,
it may not. -this somewhat depends on how your shop is wired. Don't
expect a converter to help much of this either, if the shop wiring
is at fault there is not a big chance that using a converter will
make the machine immune to the problem. bottom line with these is -
if you don't have a reason to need it, then expect little gain from
doing the conversion, and you probably will see no difference in the
machine performance. if you need it - then you probably should
expect to make some upgrades or changes in the shop wiring too. you
need an electrician to look at the wiring you have to see what the
actual situation is doing. If you have any nearby acquaintances of
this kind, many ham radio operators or industrial electricians could
walk you thru this in a few minutes of looking and testing, then
tell you what needed changed. an older but still informative,
general rule is that over 1 HP is usually on 220 but many plug-in
(shop) appliances and tools make lies of this now. A lot of the
older equipt was usually 3/4 HP and under on 110, higher HP on 220,
seldom used three phase unless used in industrial environment and
usually then above 2 HP.
(4022) |
| 220 |
| My lathe (Model A)
hasn't shown up at the door yet, but when it does I will be
converting it from 220/3ph to 110/1ph. Does anyone have advice to
offer before I burn my money? Flash (5359) |
| I converted
my 1941 A to a VFD/1 HP 220 volt-3ph with a package from Dealers
Electric. I got spoiled by the variable speed on my little 7x10 mini
lathe. I love the soft start/quick stop as well as the variable
speed (within reason). I don't think you'll find a 120 volt VFD
though, and since you said 120 volts, just get a 1HP max 1720 RPM
reversible, capacitor-start motor, preferably TEFC (Totally Enclosed
Fan Cooled). If you can stay at 220 volts, just buy a VFD for around
100+ bucks and you're good to go. All that being said, people get
away with using any old motor (even an open frame washing machine
motor). Probably no help whatsoever. Paul R. (5360) |
| Is there any danger
to the lathe from up-gunning to a full hp? Last but not least,
why would I want one to be reversible? Flash (5361) |
| Should be fine if
you're running with a flat belt (leather or synthetic). It slips
well before something really expensive would break (except flesh and
bone). Probably can't transmit a full horse via a flat belt anyway.
Paul R. (5362) |
| Nope just remember
to keep the motor V belt or flat belt pulley the same size this will
keep your top speed the same as stock. as for too much HP, I put a
1.5 HP motor on my 9" and have no problems other then pulling more
amps. The belt drive keeps you from doing damage. kerry (5365) |
| I just went through
the same thing 3 weeks ago. If you can swing it, go with 220v single
speed, you draw less amps, smaller wire, etc. Your house ( shop?)
probably already have it for the dryer, stove, water heater, etc.
Several people from this group home machinist page said to go at
least 3/4 hp (mine had 1/2 3-phase) and that 1 hp would be better. I
spent $2 each on a 3/4 hp open drip-proof and a 1 hp TEFC. The
latter needed a new bearing ($9)and both needed a bushing (pulley
was 3/4", motor shafts were 5/8") for $3. Seems to work okay. Most
22v single-phase motors can also be wired for 110v, and can be wired
to run in either direction. I managed to set mine up the wrong way.
Reversing is needed to cut metric threads, but several people
advised me to not hook mine up that way because the chuck might spin
off if you reversed it without stopping first.
(5372) |
| I'm trying to
visualize why reversing has anything to do w/ metric threads. I'm
also trying to visualize wanting to cut a metric thread. :-] I am
stuck with 110 because I don't have the service capacity to run both
into my garage and Lights, drill press, dremel tool, fans, shop vac,
compressor etc., etc. have to have 110. (5373) |
| The phase issue, I
wouldn't waste time and money changing out a good 3 phase motor and
control panel/switch. Stick with 220V and spend the money on a VFD
if you have it to burn. If saving is important, get a free 3 phase
idler motor from the scrap yard, wire it in the system, and start it
with a pull rope to provide your 3 phase conversion. There are plans
all over the net, probably even in the archives here to make one as
basic or as sophisticated as you want. Keeping 3 phase is nice for a
lathe because of the instant stop, start, and reverse ability. OTOH,
if you really feel more comfortable with it, 1 HP single phase
motors aren't expensive. Good luck either way. Hope your new lathe
is "better than you expected" when it arrives! smt
(5374) |
| You don't "have"
to. But since most lathes don't have metric threading dials, which
require different gears for different pitches, the only effective
way to avoid losing your thread, is to back out the tool a few
thousandths at the end of the cut, and back (reverse) the lathe up
to the starting point, dial the bit back in again, start cutting,
and feed in the next increment. If you disengage the halfnuts while
screw cutting, it can be "difficult", especially with very odd, or
metric, threads, to re-engage them with the tool in the same axial
position. I.e., back exactly in the last cut thread as opposed to a
little bit sideways, one way of the other, destroying the thread.
well, I'm with you there. Camera equipment, or Japanese
motorcycles... run both vac, If you are saying you need to run one
line, then use split 230 volt. You get 230 across the 2 hot leads
(red and black), and 115 between both red and neutral, and black and
neutral. Just balance the system so that about 1/2 the 115 load is
on each leg. Also, do use proper wiring, and grounding. The best way
is to run the 230 to a small sub panel. Then take off what you need,
in whatever form (115 or 230) you need, from there, sizing the wire
for each circuit as appropriate. You will get more load capacity for
your wire size running it that way. In fact, given what you mention
running, if all on at once, you may not have the ampacity on say
10gage wire to run a long branch on only 110v. smt (5375) |
| When you put on the
metric change gears, you get oddball ratios such that the thread
dial is no longer effective. Therefore, you must reverse rather than
open the half nuts. (5376) |
| As mention above
you can't use the thread dial to cut long runs of metric threads on
an American lathe Although you could re-engage the halfnut on the
same number for short threads that are not critical. But the safe
way to go is to back the tool out and reverse the machine to feed it
back to the start. Now if you lose tracking on a thread there is an
easy way to pick it up. set your compound to be 90 deg to the cross
slide this will allow you to feed the compound backward or forward
as needed to pickup the thread. the down side is that now you have
to feed with the cross slide. As for reversing a single phase motor,
You can't throw it into reverse like a three phase motor where it
will slow then reverse no matter the speed. A single phase motor
needs to be almost stopped to be reversed if not it will just keep
going the same direction, unless you buy a instant reversing motor
and that's another story. Kerry (5379) |
| Flash; One HP isn't overkill. As to being
reversible - well... Some folks like to have a reversible spindle,
it's particularly useful if you do toolpost grinding. The downside
is that with a threaded spindle, when running in reverse, a tool
catch can spin a chuck right off. Reversing direction can give a bit
quicker or better results when polishing turned work as well. There
is one other time reversing motors shine. When doing some threading
operations, you may not want to open the half nuts, as you've set up
the gear train in a way that the thread dial doesn't work in quite
the usual way, or you don't have a threading dial. It's a darn sight
easier to stop the lathe and run the carriage back under power than
to hand turn the spindle backwards, particularly if doing a long and
coarse thread. Instant reversing (3 phase) motors add more fun, more
than one person has hit the wrong button, seen the chuck start to
spin off, hit the forward, and heard a loud thunk as the chuck spins
onto the spindle hard. In bad cases, you end up turning off the back
plate. In really bad cases something expensive breaks.
Stan (5384) |
| Flash: I was
recently in the same position as yourself, with the added
complication of not having a permanent base of operations (house
hunting is ongoing). Although on the pricey side of things, AC Tech
makes a VFD (variable frequency drive) that will take either 110 or
220 single phase input and convert it to 220 3ph, with variable
speed and reversing to boot! It cost me $175, but now I'm able to
get the best of all worlds no matter what power is available. Tom
(5386) |
| Three phase
440/220 |
| Does anyone
know if you can change a 3-phase motor that is 440 down to 220
3-phase. There is no tag on my motor, just the electric box
tag, which reads 440. Or would it be easier to change my Balder phase
converter to 440 (from 220)?
(7328) |
| It's easy, if not a motor winding shop will make the winding taps
for you. 440v= hooked together 4 7 5 8 6 9, line on 1,2,and3. 220 v=
hook together 4, 5 and 6, one line to 1 7 one line to 2 8 and one
line to 3 and 9
(7331) |
| This is done with an ohmeter. If the motor is 440VAC
the field windings should be in series for each phase; they should
be reconnected in parallel for 220VAC. (7354) |
| Motor
Replacement? |
| I picked
up a 10" SB at an auction Saturday. It is in pretty good shape from
what I can see so far. The ways show a little wear - you can feel it
but not see it. From what I've been able to learn so far, it is a
bench-mounted 10" toolroom lathe from the early to mid forties (Cat
#8187YN; Ser #170216). It has the taper attachment, 5C collet
attachment (handwheel), threading attachment, and a 6" 4-jaw Buck.
It's missing the toolpost. I couldn't believe I got it for $350 -
especially after a small, beat-up Enco mill went for $750! Anyway,
it has what looks like the original Westinghouse 3/4HP 220/440V 3 ph
motor. Is there any reason I can't replace that with a nice little 1
- 1.5HP 110V single phase motor? Any "gotchas" I should watch out
for when picking a motor? Wallace (7671) |
| I don't there is
much to it. Mounting hole match, overall dimensions, shaft diameter
are so things that come to mind. I think its been done a lot. I'm
trying to go the other way, though, so you Wallace, or anyone else out
there who finds themselves with a spare 1/2 - 1 HP 3 phase motor off
a SB lathe or other, I may be interested in your motor. Rick K.
(7676) |
| The 9" SB that I
have came with a 1/2hp (IIRC) 3 phase motor. Currently I'm using a
1/2 capacitor start 110v motor (off my air compressor). I have
another 1/2 motor but it is not capacitor start, the mounting holes
and shaft are also different. As I would like to get my air
compressor going again I'm wondering if the other motor will work on
the lathe. I doubt that it would have the starting torque required
for the compressor but it might have enough for the lathe. The
capacitor start motor has lots of torque and I can squeal the belts
if I have a heavy piece mounted. Before I start modifying the mounts
and making a pulley bushing I thought I'd check with the group for
their expertise and experience. John (7677) |
| John, Your
compressor motor is likely to be 3450 RPM, as most are. For your
lathe, you need a motor that turns at 1725 RPM, and a half horse or
better; either capacitor start (preferred), or split phase (no
capacitor). Ideally, however, you may want to have a 1/2 or 3/4
horse DC motor or VFD (variable frequency drive, 3 phase)
motor/control, for easy and convenient speed regulation. The later
options come at a price, but if you shop around, you may find
something within your budget. Norman (7679) |
| Norman My
compressor motor is 1725 RPM, that might explain why it is so
sloooow, the tank is also too big, but the price was right. If my
non-capacity motor has enough torque then I'll go ahead and make it
fit as I need my compressor back. I'd love to have variable speed
but I'm a newbie and am still learning the basics so I can live with
the cone pulley adjustments for now. John (7681) |
| John Just a
thought if you could get a couple of bolts in and get the pulley
tight enough so it wouldn't t slip you could put a heavy chunk of
iron in try starting it. It would shake pretty bad with the pulley
off-center but you wouldn't have to run it that way; just see if it
will start and if it does start OK then make your modifications. Lew
(7682) |
| Relocating the
motor drive on a 9" |
| I'm going to
be relocating the motor drive on my 9" from horizontally mounted
behind the lathe to overhead. As part of that, I'm going to be
building a mounting frame out of u channel to hold the lathe and the
motor drive setup in the proper orientation. I'm thinking this will
just be a piece of horizontal u channel that the lathe bed bolts to,
with another horizontal piece coming out the back of one end
perpendicular to the lathe bed, and a vertical piece rising off that
to provide a mounting location for the motor drive pivot plate. Oh,
and some diagonal braces to help hold everything rigidly. How anal
do I need to be about ensuring that the drive pulleys are in line?
Are the flat pulleys leather belt super sensitive to misalignment?
I'm wondering if I need to just be careful to ensure that things are
in line when I build the mounting frame or if I need to build in
fine adjustment capability. Mark
(7804) |
| I recently
redid mine and holding the accuracy possible with a combination
square and a pencil was plenty. I would brace it though. (7822) |
| Actually, I'm
in the process of swapping with a friend who has welding
capabilities for a new bench...leaning [no pun intended] towards a
bench that just looks like a giant channel-stock sawhorse, with
another piece of channel stock coming up from behind the headstock
and leaning back about 30 degrees off vertical, and a brace running
from the upper end of that to the foot below it, forming an obtuse
triangle as viewed from the end. The triangle is the strongest
structure--you can't change an angle without changing one of the
sides' length, which is not true for anything with more than 3
sides. I figure if I slot the channelstock horizontally to provide
adjustment in one axis and the countershaft-support foot is already
slotted to provide adjustment in the other axis, it ought to be a
done deal except for adjusting the belt length. I'll post a pic or
two when it's done.(7823) |
| Have you looked at
the transmission tables that Harbor Freight sells ? They're steel
tables with a large grate that covers a drain pan the full size of
the table. With a weight rating of something like 1000lbs you could
put both a lathe and a mill on one of them and have a great setup
for coolant use recovery. Overkill for the mini-lathes but a good
size table for a Southbend or a mill. Dave
(7826) |
| A buddy and I whipped up a
'bench' out of some channel misc. steel that was laying around this
weekend. It mounts the motor overhead, greatly reducing the depth
needed for the lathe. I'm very happy with how it turned out except
that the drive pulley's oil can drip down onto the lathe. I'll have
to rig up some oil catchers. Other than that, it turned out great.
Stuff that was a bit more tricky than a regular job was that we
needed to reposition the belt tensioner to get the handle away from
the chuck, and we needed to use some 90 deg. 1/8" pipe fittings for
the drive pulley oilers. A pleasant surprise was that the drive
pulley isn't right out in your face. I was originally thinking I'd
need to fabricate some type of guard, but its well away from your
head, so I can skip that. *pictures no longer available* We took some cuts after we got it all together
(first ones for me with this machine!). No chatter or anything
taking an .080 cut in AL at high speed, so we're thinking the new
mount is plenty rigid. Certainly its a lot more rigid than the metal
desk it was mounted on before... :-) In the coming weeks I'll use a
strut rod to check level / bed twist and make up the oil drip trays,
but I'm definitely happy with the new mount setup. Mark
(7853) |
| Well done!
Interesting solution to a common problem. In my imagined version,
since I have a floor pedestal, I'd be building the counter-shaft
pedestal from scratch, and use sealed ball-bearings. That would
eliminate the oil problem. I also don't think I would bolt the head
stock to the vertical member. Anyway, thanks a bunch for the report
and pictures of your hard work. Sounds like you've got a nice setup
now. Helps me figure out how I might do mine. Paul R.
(7876) |
| I'll have to
look at it with the goal of changing the bearing type. As an added
bonus, there'd be one last thing to oil. What would concern you
with bolting the vertical member to the headstock? Mark
(7879) |
| Mark, My
concern is that there could now be a new source of motor vibration
and deflection on the head stock. Think of the head stock as a
pendulum swinging on the ways. The new side-to-side motion directly
translates into surface finish on the work piece. Probably more
paranoia than anything else, though ;-). On the other hand, having a
belt pulling vertically rather than horizontally would tend to
reduce this effect. Lathes on line-shafts or UMD's probably turn
smoother (microscopically). Paul R. (7898) |
| Bodine motor
data |
| Motor experts in
the group, I need some help in determining the connections for the
start and run capacitors and power-in connections for a Bodine
gearmotor I purchased for my die filer. Bodine tech support tried to
fax the data sheet but my FAX machine failed. They seem reluctant to
answer my e-mail or re-send now that I have replaced the FAX. Dave
(9752) |
| Mike Smith's
response made me go back to the Bodine site and look again for motor
data. The key is to use the motor's first 2 numbers and the
following letter in the search from the home page. In my case, I
searched for a 44C motor and came up with 2 publications totaling 52
pages. I was originally trying to input the whole model number then
smaller and smaller parts but gave up before getting down to 44C.
Thanks to all of you who helped. Bodine did re-FAX the spec sheet
that originally didn't come through. So I have my data. Dave
(9766) |
| I have
posted the Bodine 44C Motor Wiring Diagram in the Files Section of
the Yahoo Mill_Drill Group for those who expressed interest a few
weeks ago when I posted a question. The diagram is a composite of
what Bodine sent me and my own measurements and observations. It is
in .WMF format which I converted from the AutoCAD original where I
created it. Dave (9834) |
| New motor for
SB 9" A |
| Thinking about
replacing the 1/3 hp single phase motor on my 9" Model A lathe with
horizontal drive. Any suggestions about what motor to switch to? I'm
thinking TEFC 3/4 hp or 1 hp single phase, 1725 rpm, 115V or 230V,
56 frame. Is this too much motor? Should I consider a 3600rpm motor
to gain spindle speed? VFD driven 3-phase to gain variable speed is
a possibility, I have an 1.5hp motor 3 phase motor already, but
would need to purchase VFD. What do you use on your SB 9"? mark (9632) |
| Mark A 3/4 HP will
be just fine. I would stay with the 1750 RPM motor You can consider
using a DC motor and variable speed controller if you ever have a
need for higher speeds??? or it is really good for lower speeds.
Clint (9633) |
| I have a 1/2 hp on
my 10k and it is just a tad too little. 3/4 or 1 hp is a better
choice. If I ever bother to change motors, I will go 1 hp. Frank
(9634) |
| Mark, Mine was
built with a 1/2 HP/1725rpm motor. That's plenty enough. RichD
(9636) |
| Mark: For a 9"
lathe, a 3/4 HP motor will do very well for you! I have used 1 HP a
couple times but have never felt that it was needed. Do not make the
mistake of using 3450 RPM. You will never be able to get your
machine to run slow enough. Even if you choose to use carbide tools
you will get all the speed you need with a 1725 motor. If you can
afford to go the VFD route, that is the Cadillac of drives but they
are very expensive. Desmond
(9638) |
| Electric motor |
| The GE electric
motor on my SB 9 has given up on me. The last time I ran it, smoke
came out of it and as an old electrical engineer once told me, when
you lose the smoke, you need to replace the motor. There are no tags
on the motor to give model number, HP etc, so would appreciate any
help in what manufacturer, type, hp, etc I need to get for
replacement. I did take the old motor apart just in case it could be
fixed and found a lot of corrosion inside on the windings and shaft
so think it is time to get a replacement. Are there used motors
available? Barry
(10745) |
| Grainger's
does stock an exact replacement. Mine came with one. It's a 1/2HP
capacitor start, ball bearing type. A couple of months ago, suddenly
smoke came out of mine, also, but I was lucky. I was turning copper
and by some bizarre chance a fine turning got into the air intake of
the motor and found its way either to the starter contacts or the
terminal block! In a panic I got the nameplate (It is around here
somewhere) and checked it at Grainger's online catalogue and did
locate it. I shall find it again and post the stock #. Used ones do
turn up on E-Bay, but the ones I have seen, the sellers seem to be
aware of the prices of new ones.
(10746) |
| Grainger's
lists a couple: # 4K781 @ $ 168.25 and #4K142@ $ 179.50. However,
there are some on E-Bay, including http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem
item=2527756629 category=1272 which is right now at *ten dollars*.
You might have to bush the pulleys, etc., but the ratings are right
and the frame looks like the right type, comes off a 12" Craftsman
lathe. There are lots of motors on there so you should be able to
avoid paying the New prices.
(10747) |
| I buy 1700 rpm
capacitor start 1/2 hp motors as I find them at flea markets etc for
20-25.00. (10748) |
| Barry,
Myself, I would try to buy a new motor from Grainger. (10750) |
| In the back
of a Grainger catalog there are direction for measuring a motor to
find the frame size. it is very straight forward and easy to do. LaRue (10751) |
| Harbor
Freight has on on sale @$79.99. Ball bearing and reversible. Jim B
(10752) |
| Wow, that
sounds like a great deal! Is it Ball Bearing? (10753) |
| You can get a
surplus 1/2 HP 3 phase motor for less than $50.00 and a variable
speed drive from e-bay for less than $100.00. easily the best way to
replace the motor. In a pinch, consider a washing machine motor if
you can't wait. 1.2 seems to be the normal, but you could use 3/4
with no loss. I would go for a compressor rated cap start cap run -
reversible motor if I was to stay with an AC motor. Dave (10756) |
| Try
http://www.surpluscenter.com
they sell almost any type motors there is, at really good prices
also. Clint (10762) |
| The motor in
question is reversible, true - but I thought that an "instant
reversible" motor is required. Can someone comment on whether or not
this is true? These motors are much more expensive. Denny (10779) |
| You do not
want an instant reversing motor. If you already have one it will
work but it will tear up the machine and the belts. Think about the
inertia of the chuck and gear train moving at a few hundred RPM
grinding to a halt and instantly starting up again. There are no
operations that need instant reverse, Most 3 phase motors are
reversible. max (10780) |
| Just to
clarify. My lathe currently has a 3-phase motor, which is
essentially instant reversing, right? If I replace it with a 1-phase
motor (not instant reversing), I can still use a switch to run it in
reverse. I just have to wait for it to stop, first. Is that right?
If so, what type of switch should I be looking for? Denny (10793) |
| I am an old
electrical engineer. The smoke is what makes things work. When the
smoke goes away, things stop working. Another rule of thumb, don't
blow away the smoke. The smoke tells you what is wrong. Glen
(10797) |
| Caution -
instant reversing on three phase motors causes a very stiff torque
pulse in the driveline and can damage items very quickly. this will
also spin the chuck off of the threads and toss it away from the
lathe or batter the threads on the spindle and twist the tailstock
of you have a workpiece between centers. You do NOT want to find
this out the hard way - it is very dangerous. even with no chuck on
the spindle, the energy stored in the inertia of the driveline may
be enough to over stress your supports and brackets securing shafts
and motor. There is no good reason to 'instant reverse" work in
these era design lathes, whether you have a screw-on chuck or not -
these machines were not made for it and are not safely tolerant of
this practice. Even when furnished with three-phase motors, the
workshop and toolroom machines had smallish motors ( 1/3 or 1/2 HP)
compared to the retrofits we are talking about here. for my purposes,I find it is no great discomfort to let the chuck stop
normally and then start the motor in the reverse direction.
Reversing a three phase motor while under power is called '
plugging' and is responsible for a lot of damaged equipment. just
because they will do it does not mean that it is safe or even a good
idea to try. The motor and the electrical gear controlling it are
normally specially sized for this duty, and the driven application
is designed for the heavy torque load it imposes. even reversing a
small 3-phase motor under load generates more heat in the motor and
reduces the available duty cycle: the energy of the machine inertia
is transmitted through the driveline to the motor's magnetic fields,
which act as an electrical brake to absorb this energy and then
accelerate the parts in the opposite direction. the majority of this
energy converts to magnetic force and then to heat inside the motor.
James (10821) |
| I agree with
the above post on not reversing you lathe instantly or near
instantly, but if you need to reverse your motor get an AC drive
then use the braking and ramp up programming to slow down the spindle
then slowly speed it back up in reverse. Most drive will allow you
to set the braking and ramp up. braking is exactly that it slow the
motor down faster then letting it coast and you can adjust how hard
the "brakes" are applied. Ramp up is throttling the motor more slowly
then just flipping a switch and giving it everything at once. it
brings the motor up to full speed over a few seconds instead of as
fast as it can. This can help to start big motors when you don't
have quite enough amps to do the job. But like stated before and I
have to force myself to listen. these machines were not meant to be
thrown in reverse like a modern machine. Kerry (10836) |
| SB 9 motor |
| I would appreciate
info on a replacement motor for my lathe. I know there have been
several postings on this subject but would like to get confirmation
on the right spec for the motor. I understand that the motor should
be 1725 RPM, but if not reversible, is rotation CW or CCW? Should
the HP be 1/2 or is a larger HP better? Also, what should the amp
rating be for the motor when operating? I would also like to get
confirmation that the frame size is 56.
Barry (10875) |
| Measure
twice, order once. there are lots of places on the web that give
exact motor dimensions. better to measure what you have than get
what someone else tells you to. reversible will be available, so
don't consider one that is not. 1/2 is the original spec and the
imports supply a 'Chinese' 3/4 hp. if it anything like the 'Chinese
1/3' hp motors on my drill press, it really would be a tad under 1/2
hp. more motor and you can break things. Check for local suppliers,
Grainger sells them so you can always order. Dave (10876) |
| Here
is the data from the nameplate on mine; It had been replaced ~15 years
ago: The direct replacement is a (Grainger's) Dayton #4K 781R,
Capacitor AC Motor, 1/2 HP, ball-bearing reversible motor that can be
jumped for 115 or 208-230 VAC 60 Hz, 9.6 Amp full load @115, 4,5-4.6 A
@115-230 Frame 56, SF 1.0 That stock number may be old, but I searched
their site and found a couple that are similar, as well as an
equivalent at MSC Online. (10877) |
| Barry, In my
9A (original factory all the way) G.E 1725 RPM, 1/2 HP, 50 deg rise.
Normal (forward) rotation CW). RichD(10883) |
| I
would like to know something, I have a couple of reversible AC
motors laying around the shop. I have never reversed one however.
Would this work OK with just a forward reverse switch? or once wired
for a particular direction that is it unless it is rewired again?
can someone shed a little light on this for me? Clint (10890) |
| Clint,
Most reversible motors require that the field wires be reversed on
the terminals under the cover plate on the bell housing. If you
bring out leads from the terminals and extend the wires to the field
windings, you can hook up a DPDT motor rated toggle switch to allow
reversing. If you can find a drum switch in the correct
configuration, or a 3PDT switch, power can also be controlled by the
same switch. If not, you end up with a direction switch and a power
switch. If you pull the wiring cover panel from one of the motors,
the connection instructions are usually pasted to the inside of the
cover panel. Holding the switch with the terminals up, with the
three terminals at each side, the terminal lugs connect to the two
center terminals The field winding leads go to the two terminals on
the top or bottom, doesn't matter. The top right terminal gets wired
to the bottom left terminal, and the top left terminal gets wired to
the bottom right terminal. If you use short wires for the top right
to bottom left, top left to bottom right deal you end up with a wire
"X" with the crossover between the two center terminals. Probably
easier with a picture, but I'm pretty poor at creating
understandable ASCII art. Stan
(10891) |
| Clint,
Some reversible motors are easier to wire-up to a reversing switch
than others. Most later motors use the NEMA wiring standards and
have separate wire leads that are numbered (like T1, ... , T5, T8).
These are the easiest to explain and IMHO, the easiest to wire to a
reversing switch. Leads T5 and T8 are used to determine rotation of
the motor. If yours is this kind, there is (or at least should be) a
connection diagram or chart showing how the leads are connected.
This should be either on the motor I.D. tag or under the cover plate
that allows access the leads. Older motors may use color coded leads
or have a circuit board that you connect leads to and/or has
"jumpers" or "shorting bars" to make internal connections. The
latter are the more difficult (but not impossible) to wire to a
reversing or "drum" switch. If yours has the circuit board
arrangement, you will need to identify leads and probably have to
cut and splice new leads into the motor in order to get it to be
reversible from a drum switch (bypassing or eliminating the circuit
board completely). This is not too difficult to do but you need to
understand how a single phase electric motor works and how it
starts. Also an Ohm meter is an essential tool in this kind of work.
Before going on any further, I recommend that only capacitor start
motors be used on machine tools (that is, instead of a plain old
split phase motor). They have more starting torque. (Yeah, I know;
repulsion start motors have excellent starting torque and would be
good for machine tools too but they are not very common). Also, the
motor should be rated for continuous duty. And a service factor
greater than 1.0 is nice too but not necessary. If you have a
reversible continuous duty capacitor start motor with separate
leads, then you are in business! If you know what leads your motor
has and the type of drum switch, post them and someone here should
be able to tell you how to wire it up. Webb
(10892) |
| Stan and Webb, this help a lot, I think that I can figure it out. I will go
thru some of my old motors and see what I do have. Once I get some
more info I may need to call on you guys again I will keep these two
postings handy. Clint
(10893) |
| I had a 1.5HP
motor on my 9" junior. Worked fine just the motor itself was real
loud so I put on a 1HP and it works fine too and not loud. 1HP I
would say is the max on a 9" I've got mine running with a larger
motor pulley to get a top speed of 1000RPM. Now I don't use the top
end much but it nice to have for the few times I've needed it. But I
do watch the temp of my bearings when I run it that fast and I don't
leave it running to answer the phone. There's a reason they designed
it to run at 650 rpm. so I don't want to push my luck. Kerry (10913) |
| DC Motor
conversion |
| People have asked
me for wiring diagrams. A good set comes in the manual for the
controller I bought from Graingers. The wiring of the 4PdT switch
for reversing rotation and turning on the AC can be found at:
http://www.dartcontrols.com/InternetConfig/Manuals/125DManual.pdf
The general scheme is valid for any full wave SCR controller.
(11879) |
| I just received
a copy of the Dart Control Instruction for the 125D control. What
page references the hook-up I should use and how do I insert the
ammeter? Bob (11911) |
| I just received a
copy of the Dart Control Instruction for the 125D control. What page
references the hook-up I should use and how do I insert the ammeter?
I found the ammeter is only a frill. I put mine in series with the
AC line because I happened to have an AC Ammeter around. If you do
that I suggest a 10 amp meter. An DC Ammeter on the armature side
should be 6 amps full scale for a 1/2HP motor and 8 Amps for a 3/4
HP. BTW, there are some great 3/4 HP controllers on E-Bay that are
much better than the new $70 ones from Grainger's, and going for
about $50. They have adjustable acceleration. The new Darts from
Grainger's are set at 6 seconds to full speed, something I found
annoying. The KB Penta Powers on E-bay require a calibration
resistor, about $1 or $2 from Allied, depending on the size motor
you use. I got a 3/4 and am using that as it gives a comfort factor
for torque. (Also from EBay.) The KB units will run 3/4 HP with NO
ADDITIONAL HEAT SINK! The Grainger's Dart controls want an
additional heat sink. The top of Page 9 in the Dart manual shows the
wiring for the 4PDT switch. This is common to any such control.
(11914) |
| Lathe motor
base/mount |
| Are there standard
bases for motors? I replaced the motor on my 10k and bought a new AC
1/2 hp from a local dealer and it fit perfectly, but he knew where
it was ging. How can one tell if a motor will fit existing mounting
holes? Frank
(12812) |
| Most
fractional HP motors are made with standard bases or mounts. There
are several types, but most of the motors for small machine tools
use the "56 frame" mount. RichD (12814) |
| S/B Motor size |
| I have a s/b 10 x
36 it now has a 2hp 3phase motor in it what size motor did these
lathe come with it seems to me that this motor mite be a little
large for this lathe please help. JIM (13043) |
| I restored
mine with a NOS motor from Dayton, it must of sat on a shelf for 20
years... it's so perfect. I think it was a 64c frame if I remember,
I think that was the replacement motor, I know the Horse rating is a
little more than what was on the original 3 phase one, which is
generally a good idea. If I had my original 3 phase, I would have
given to you, but I think it went to the scrap yard. Jason (13044) |
| I'm not sure
what frame it was actually, and I can't read the stamping
underneath... it was either a 46, 48, or 64 type, probably one or
two of those aren't real motor sizes. Jason (13045) |
| If you are
talking heavy 10, the stock motor on mine was 3/4 hp (1953 vintage)
The bimetal strip capacitor switch burnt up so I ended up replacing
the motor with a 1HP. John (13064) |
| Motor
recommendations needed |
| I'm
looking to replace my motor on my SB 13" with a single phase unit.
I'd like to continue to have "reversibility" like I had with the 3ph
unit. Have any of you done this? Pitfalls? Recommended motor types
and sources?
(13077) |
| If the 3
phase motor you have works fine, consider getting an Inverter (VFD).
You can run it off single phase 220, make it variable speed, etc for
less than the price of a new motor. I do this with my Bridgeport and
it works like a charm. John (13078) |
| Michael, Try
looking for motors at http://www.northerntool.com/catalog/ I bought
a 5hp 1ph 184T frame Marathon motor from them and it was cheaper
than any I could find locally. It runs my air compressor and has
been very reliable. (13080) |
| I bought a
1.5 HP single-phase GE motor (P/N 5KCR49SN0065A) from Grainger for
my 13". I had to make an adapter plate because the NEMA
mounting from the original motor was obsolete. (13090) |
| Do you
remember what size the obsolete NEMA plate was on your lathe? I
found a NOS Dayton motor luckily, but I can't for the life of me
remember what frame it is, and I can't see under the drive to read
it. I keep saying it's a 64c frame. or 48c frame... The thing is,
the C series frame available now are something called skeleton
frames. I don't think the original 3 phase Westinghouse on my 10L
was a skeleton type. Jason (13091) |
| Grainger for
from the original funny picture. it's not real ! no rust, no grease,
no leaking oil stains and no chips!
(13119) |
| Motor - Single
or 3-phase? |
| I have a
13" South Bend that I picked up, but do not know if the motor is
single or three phase. The plug on it is a configuration I do not
recognize, but the wires from the plug to the drum switch are the
standard white/black/green. I did hook up the wires to a 220v
outlet (single phase) and the motor appears to run fine. I do not
have the belt for it right now so I do not know how it will run
under load. After this experiment I would assume it is a single
phase motor, but is it possible I have only energized one set of the
windings in the motor and it just happens to run? The motor starts
right up like electric motors usually do - there is no hesitation.
According to the data sheet from South Bend it shipped with a three
phase motor, but that doesn't mean it wasn't replaced. I can't find
a data plate on the motor. Alex (13196) |
| How many
wires does it have coming from the motor, normally the 3 phase will
have 9, some have a different number, but this is my understanding
of in general Since it started right up OK, I would assume it is
single phase. Clint (13198) |
| 1. there
should be a printed or embossed nameplate riveted on the motor -
this will tell you what the electrical characteristics are 2. look
inside the motor terminal box - there may be a label showing the
wiring and characteristics. 3. find the motor brand name and any
data on any identification plates and we can help look up the data
from that if it is a 110 V motor it may start and appear to run fine
under no load on 220 but may very quickly overheat and burn up.
induction motors derive their rotational speed from the speed of the
system ( 60 Hz) and not the voltage so it would turn at nearly the
same speed as if it were on the correct voltage. if it was a 220
plug - it was most likely a standard type item and can be identified
- many plugs are made specific to the voltage they are intended to
carry so that people don't plug them into something inappropriate.
take a picture of the plug and post it so we can identify it. be
aware that if you are dealing with electricity, you are handling a
lethal dose of energy. it is NOT safe to experiment with it and you
may be risking serious injury if you do not have the proper safety
equipment and training. but the white/black/green.
(13203) |
| Alex, Sure
sounds like a single phase motor to me. Three phase motors typically
have 4 (or more for some configurations) wires, and don't usually
start if they have just a single phase applied. If the green wire is
ground it's certainly single phase. If you have an ohmmeter, just
check for continuity from white to black and verify neither of these
leads has continuity to green. Stan (13204) |
| I did finally
find the data plate it was very well hidden under the box where the
wire connections are on the motor. Even harder to see since the
motor is so close to the ground. 1 HP Single phase. Thanks fo
everyones input, Alex I'll post some pics when I am done with the
restoration. (13220) |
| Problems
starting lathe |
| I've just about
finished my rebuild of my heavy 10" but I'm having problems getting
the lathe to turn over. I have the old pedestal type with and if I
have selector that powers the leadscrew and drive train in neutral
the lathe will turn over but the motor has to come up to speed or
sometimes I have to grab the chuck and give it a little push to get
the lathe to turn over. If I engage the level to power the gear
train the lathe wont turn over at all. If I remove the gear that is
connected to the lead screw at the quick change gear box, the lathe
still has problems turning over. I can turn the gear that is
attached to the lead screw by hand while it's connected to the gear
train. Any ideas as to what is wrong? I've left the quick change
selector out of gear so I'm not trying to power the quick change but
still it won't turn over. When it is on and not turning, I don't see
any belt slippage either on the motor to pulley that is attached to
the lower 3 step pull or the leather belt that goes between the two
3 step pulleys. Is it possible that the motor is burned up or since
it's a two speed 3 phase motor, is it possible the starters are bad?
I apologize for my lack of terminology but I don't have the repair
book with me at the moment.
Terry (13382) |
| Check the fuses first, you could
be trying to run it in a single phase condition. Look for three phase
at the line side of the starters. A-B B-C and C-A should all have
line voltage. Make sure the motor is connected for the voltage you
are using. Those are two things that will cause a three phase motor
to fail on start, even though it will run with no load ,if you give
it a push. I worked on a Sheldon that was connected for 460 volt
operation last spring and the labeling tags were under the
tape. Until I unwrapped the tape I thought the leads were un-labeled. Changing
it to 230 volt operation became an easy task when I discovered the
labels. My point is don't lose track of the labeling on those motor
leads, a dual voltage motor has a lot of coils. RC
(13384) |
| Terry, When
the spindle is not turning, and you say you do not see any slippage,
is the motor still turning or does it quit? in other words, when it
quits turning, does the motor stop also? or does the motor turn and
the spindle stops? Have you got 3 phase power or a static converter?
Clint (13385) |
| With the gear
train in neutral and if I turn the power on the lathe will power up
to speed. I then turn it off wait for the head to stop and engage
the valve train either forward or reverse. Turn power on and nothing
moves. When I look at the motor the shaft is not turning that powers
the v-belt pulley to the large 2 step pulley that is on the same axle
as the lower 3 step pulley. If I give it a push, then the motor will
turn over and the lathe will come up to speed. If I have the quick
change gear box engaged then I can't even turn it over by hand, so
I'm not ruling out that I messed something up in the quick change. I
have true 3 phase power at the shop at 220 volts but I need to
double check that the motor is not setup for 440. Also, when the
gear train is running, it's pretty loud. Not making a grinding noise
or anything just noisy. I'm hoping that since these are straight cut
gears and not meshed that the gear train is just going to be noisy
when running. I've taken apart the selector off the head stock and
broke it apart to clean the 2 small gears and the larger 2 gears
that are on the bearing that fits inside the headstock. I felt that
it was a little tough to turn over so I took it apart and cleaned
all the surfaces and replaced the felt. Now it turns better and
doesn't make as much noise as before but its still noisy.
Terry (13386) |
| Terry I think you
need to check out the hook up like was suggested by another post. I
do not think the problem is with the lathe, just either the motor or
the wiring. Clint
(13387) |
| Well it turns
out that my motor is a 440v 3 phase but my shop only has 220v
3phase. So can these motors be converted from 440v to 220v or do I
need to buy a new motor?
(13407) |
| You should be able
to get the motor rewound at a motor repair shop. I had a 3hp
575v/3ph motor for my milling machine rewound to 220v/3ph for $250
or so locally. (Boston area). However, if your motor is a standard
frame type, you'd probably be much better off just buying a new
motor - you can probably get one for half the price of the rewind,
or less! You could also get a step transformer on eBay for around
$50-75 that would do what you want to do. C.S. (13408) |
| I had a similar
problem with an Oliver lathe motor, and my local motor repair guy
was able to rewire without any fuss. He did say that the wires had
their original metal tags, which made it much quicker, since he
didn't have to track anything down. It cost me $20. Bob
(13409) |
| Terry Somewhere
there should be a plate showing a wiring diagram of 220/440V I think
some 3 phase motors could be only 440V, but doubtful this is your
case?? since it was with the lathe?? Have you pulled the cover off
the wiring box on the motor and see if it is on the back side of the
cover? Clint
(13411) |
| If you go
with another motor, you can pick up 3 phase 220V motors for a little
of nothing try this place http://www.surpluscenter.com How many
wires have you got going into the motor? 9?? are they numbered?
Clint (13412) |
| If it is a 9
wire and still has the tag numbers, I can tell you how to wire it.
Clint (13413) |
| I went
over to the shop and looked but the wiring cover on the motor
doesn't have a wiring diagram, unless it's inside the housing. But
the way that I have the motor hooked up is the following: Wires 1,
2, 3, 12, 13 come from the switch. Inside the wiring cover I have
these wired to wires T1, T2, T3, T11, T12, T13 in the following way.
1 - T1 - T11 2 - T2 3 - T3 12 - T12 13 - T13 The information of the
plaque on the motor doesn't describe the motor as a 220/440v just a
440v. Model 11558M45 Type COGMX Volts 440 Freq 60hz HP 1 Frame 184
Speeds 1710 rpm / 820 rpm. Terry (13414) |
| Terry I am afraid
to tell you that apparently it is for 440 only, now if there is a
way to go with 220 I do not know how but sure it can be done. What
you will find however, is you can add any motor cheaper than messing
with rewiring, etc, on that motor. Motors are just to cheap now days
and easy to find, especially at auctions, but you can find new ones
under a 100.00 All you need is a 110 V, 220 V 1/2 HP motor, or a 3
ph 220V 1/2 HP If you find used ones, do not worry about the exact
HP, you can get by with 1/3 to 1 1/2 HP motors and any of them will
work fine with your lathe, just make sure it turns the correct
direction. You can even run a washing machine or dryer motor but do
not recommend the open housing type,, the chips can get inside and
short them out. OH, make sure it is close to 1750 RPM and not 3450
If you were close to me, I have several motors just laying around.
Clint
(13415) |
| I would go with a single phase motor on a 9" lathe. That would allow
you to get rid of that starter, and just use a drum switch, if you
want reversing, or a toggle switch if you don't. The main advantage is
the increase in resale value of the machine. Like Clint says the
little lathe just doesn't have need of brutal power. Nothing is more
convenient than a 120 volt single phase machine. RC
(13416) |
| I just looked
at your members profile and it says you are in N Texas. I'm in DFW
and don't mind driving. I would be interested in swapping if you
want. Terry
(13417) |
| I am in
Austin and have a lot of experience with electrical and motors. I
make my own three phase converters, and do a lot of industrial
electrical, if I can be of some assistance please contact me.
Mike (13418) |
| Terry I do
not need the 440 V motor, but let me look at a 110 V if that is OK,
I will let you have one. If you decide later that you want a
different one then it would not be that hard to change out again But
we can find something here to get you going I am up North Of Celina,
do you know where that is? Clint (13439) |
| Terry I
forgot to mention, if you bring your 3 phase motor, we can also take
a look at it and make sure that it can be wired for 220, if so we
can test run it with my 3 ph converter Keep in mind when visiting,
my shop looks like a work shop! Clint (13440) |
| Mike Thanks,
I am sure plenty of us will need your advice Clint
(13441) |
| Terry Was you
able to get the motor mounted and tried out today? Clint (13577) |
| 3 phase? |
| Will a
3 phase motor run if given a preliminary spin with a starter rope
and then plugged into single phase 220 on 2 of the 3 legs of the 3
phase leads leaving the third leg unwired? What about rotation or will
it run in direction of spin? This is only for a little test if it
can be done. stirboy (13580) |
| Bill, Yes, it
will run, in the direction you spin it, just as you say. To make it
self starting add a motor starting capacitor in series with a push
button switch, the 3rd leg then to either of the other 2 legs (test
for direction). Adding run capacitors will make it more efficient.
Now you have a rotary convertor or a way to use that 3 phase motor
on 1PH on your mach. tool. Adding a NC relay in place of the switch
will make it automatic. Not all, mostly modern motors, will work
this well, but try it. RichD
(13584) |
| That's a fine way
to test a motor. You don't have to spin the motor very fast. I have
used a piece of nylon twine with about 10 turns around a 1" shaft.
You don't have to spin very fast; the faster it's spinning the lower
the starting surge. Starting an unloaded 7.5HP motor on a 15A 220 V
circuit this way will trip the breaker now and then. Keith
(13585) |
| Stirboy Yes
they can, but no power. With no load they will run, or at least some
of them will. They can also get hot and burn up. Clint (13587) |
| Power King
motor |
| Anyone out there
running a Power King single phase motor, on their SB 9"? My 9A came
with a Power King 1/3 HP, 6 amp, 1725 rpm, 1 cycle motor - made by
Power King Tool Co, Warsaw, IN serial # 252260 I haven't used the
motor yet, as I haven't gotten around to cleaning up my lathe - I
got it mid-summer. I was just wondering if Power King is a good
motor? Who knows, the thing might not even work. I will have to give
it a test one of these weekends. W. Sharp (13878) |
| I haven't
heard of that brand, but my 9A is powered by a 3/4 HP. 1/3 HP might
be a bit small. I can't find the recommended size in HTRAL either,
but 3/4 hp seems to be enough. W. Sharp (13987) |
| Yes they were
good motors, I don't believe they are made anymore. If it works and
doesn't smell when it runs use it. The older motors had a lot of
inertia to them and the performance of a 1/3 hp old motor is better
than a 'new' one of the same rating. If you replace it then go
bigger. My 10" came with a 3/4hp 3phase and I replaced it with a new
1hp Leeson motor I picked up on Ebay for $50. Frame sizes have been
consistent for a long time so the mounting of a new motor should be
relatively simple. JP(13989) |
| JP, Thanks
for the input on my Power King post. When I get a chance, I'll wire
it up and she if she run? Bill (14027) |
| Electric Motor
Frame Sizes |
| Would
anyone on any of these groups have access to an Electric Motor Frame
Designation Book? I have a Gray-Mills Coolant Pump on my Bridgeport
Mill and would like to change the motor from a 3 Phase to a Single
phase motor. I have been told by local Motor Rewind Shop that this
motor is of proprietary dimensions in flange mounting size and bolt
pattern and he would have to order direct from pump manufacturer. I
would like to know if he is just trying to drum up some expensive
business. I have been to manufacturer's web site but do not see my
style of pump which could be 30 Yrs old. Anyway I will give pump
dimensions and if anyone can let me know if this is standard motor
and what frame style it is I would appreciate it. BTW there is no
frame style info on pump tag. Pump is 1/8 HP and has an end housing
on it where it will sit on pump housing of 5.500". This end housing
also has a spigot on it 3.000" Diameter by .150 High. Motor is
bolted on to pump housing by four 1/4" bolts on a 3.750 Bolt Circle.
Motor shaft size is unknown at this time as I have yet to get
extension shaft coupling off but is really unimportant as I can make
an adapter to suit motor shaft and extension shaft. Ron
(16263) |
| Ron, I'm not
sure how much this will help, but try going to Grainger's web site
at
http://www.grainger.com
to try to figure out your motor. Dave
(16265) |
| Ron, Are
you sure you want to bother with this? I don't think most of us use
coolant in home shops. Ed (16266) |
| Ed: POSITIVE
Ron (16267) |
| I have a Gray-Mills Coolant Pump on my
Bridgeport Mill and would like to change the motor from a 3 Phase to
a Single phase motor. I have been told by local Motor Rewind Shop
that this motor is of proprietary dimensions in flange mounting size
and bolt pattern and he would have to order direct from pump
manufacturer. I would like to know if he is just trying to drum up
some expensive business. I have been to manufacturer's web site but
do not see my style of pump which could be 30 Yrs old. Anyway I will
give pump dimensions and if anyone can let me know if this is
standard motor and what frame style it is I would appreciate it. BTW
there is no frame style info on pump tag. Pump is 1/8 HP and has an
end housing on it where it will sit on pump housing of 5.500". This
end housing also has a spigot on it 3.000" Diameter by .150 High.
Motor is bolted on to pump housing by four 1/4" bolts on a 3.750
Bolt Circle. Motor shaft size is unknown at this time as I have yet
to get extension shaft coupling off but is really unimportant as I
can make an adapter to suit motor shaft and extension shaft.
(16268) |
| Motor size
limit for 11" lathe |
| I have an 11"
1 3/8" spindle Logan (put together from several different
Logan's)
that is currently using a 3/4 HP 110V motor. My hose has single
phase 220 juice in the basement and I have a 1 HP 3 phase motor and
a 2 HP 3 phase motor... I was thinking about using the 1 HP on the
Logan and using the 2 HP in a 3-phase rotary converter. Is a 1 HP
220V 3 phase motor too big for my Logan? I know a 3 phase motor
develops more equivalent power than a one phase so technically all I
would need would be a 1/2 HP 3PH to replace the 3/4HP 1PH 110 V.
motor. The question is will I cause any problems using a 1 HP
motor? Because I have it around and all. Kiira
(16342) |
| Here's my take on the question: Look at the original equipment
specifications on the South Bend Co. website. For the 13" Series O
lathe, they show the original equipment motor size as 3/4 HP.
Further down, they say that a 13" Series O can reduce the diameter
of a steel shaft by 5/8ths of an inch in a single pass. (Presumably,
this is some kind of very easy- machining steel, cause that implies
raising a 5/16ths" chip! Sheesh!) With that in mind, 3/4 HP ought to
be OK for an 11" lathe, assuming comparable belt drive and gearing.
There's a downside to excess power. Suppose you have an accident?
Like running a chuck jaw into something, or running the carriage
into the head- or tailstock in power feed. Accidents do happen. In
such a situation, the less HP you have, the better!!! While we're on
the subject of safety, make sure you have a reasonably- rated
circuit breaker or fuses protecting each of your machines!
Obviously, this is only an opinion based on the facts outlined
above. John (16348) |
| 16" motor
horsepower |
| My Father in law
and myself have been working on a ~1942 16" swing 8' bed (117-E). We
have almost completed scraping, painting cleaning oiling etc. The
original motor was not with the machine when we bought it. Does
anyone know what horsepower the original motor would have been on a
16" swing machine? The original vbelt pulley on that motor was also
missing, but I calculated the spindle speeds with various pulleys and
it looks like a 4" will be right.
(16363) |
| My 1960 SBL
catalog lists 2 hp @$223.00for 3 phase use and 1.5 hp @$316.00 for
single phase use. Wayne (16463) |
| I imagine
that by this date it would be a 4 step pulley machine which
frequently used a two speed motor. Even if you don't bother with a
two speeder (expensive) its well worth fitting extra pulleys to give
two speeds as the speed range is much more useful. The top speeds in
High and Low range are 980 and 470 whilst the single speed version
checks out at 490. A slow lathe can be a right pain for some work.
If I were setting up I'd be inclined to pick pulleys for 900 and 250
or 300 top speeds in the high and low range, having some slow direct
drive speeds for big jobs can be very relaxing on a big belt drive
lathe. Watching a decent cut come off a big job with the chuck
marching round in stately near silence is just soo nice. Another big
pulley for the countershaft can come expensive. Either wait until
you have things going and make one or add an extra shaft so you can
use some smaller, cheaper pulleys. I find the bearing units out of
scrap spin driers excellent for this type of extra shaft job.
Clive (16464) |
| I too,
have a 16 inch SBL. It came with the original 3 ph motor which I
still use along with a motor controller (no loss of power). It is
1.5 Hp. Philip (16479) |
| The motor we were planning on putting on for now is a
1.5hp. I was pretty sure it would do well enough but I am happy to
see that it was deemed sufficient on original equipment. The motor
we have has only 1 speed, but I have a reasonably large pulley which
will give me a rather high top speed ~1500 rpm that may or may not
be useful, the lowest of the low, if my calculations are right,
would be about 45 rpm in back gears. so the range of speed should be
good enough for most jobs we tackle. (16481) |
| Maximum Power
for Heavy 10? |
| What is the maximum
HP motor that the Heavy 10 can safely handle? When these machines
were driven by overhead belts in a large shop there must have been a
great deal of power and momentum available from the main lineshaft.
I don't want to overpower the lathe but I'm a little disappointed in
the current performance I'm getting with an old 3/4 HP motor. (17638) |
| When I first got my heavy ten I took the
3 phase 3/4 hp motor to a rebuilder and recommended replacing it
with a 1 hp motor being it was soooo beefy. It has been doing a good
job for twenty some years now. Joe R (17643) |
| New motor HP
and RPM maximum |
| I've got a
'33 SB 11" underdrive lathe that's working fine. I have been
thinking about upgrading its 1/2HP motor with something more
powerful (maybe 1 HP) and capable of providing higher spindle
speeds. I realize there are likely bottle necks in the lathe's drive
line (belt, bushings and gearbox?) and I'm wondering how severe they
are. Any rules of thumb about max power and spindle RPM a lathe like
this can accept without trashing its (presumably bronze) bushings?
Can I raise HP and keep the RPM the same or visa versa?
Peter
(18398) |
| I use a 1hp
1725 rpm on my 10" and it works fine. It came with a 3/4hp. I
wouldn't use a faster motor, just sharpen your HSS bits and trash
the brazed carbide offshore junk. JP (18399) |
| I've got an
1150 RPM motor on my lathe now. What type of spindle RPMs are you
turning? Peter
(18401) |
| What is
listed in the HTRAL book. You can resize the motor pulley to match
the rpm, go to 2/3 your current motor pulley pitch diameter when
switching from an 1150 rpm to 1725 rpm motor. My RPMs are 1357, 837,
535, 700, 434, 277, 129, 79 and 50. The change in hp from 1/2 to 1hp
will make a big difference. JP (18408) |
| SB 9
replacement motor help |
| My SB 9"
has a Century A66 motor set up for 480v and I would like to find a
replacement motor that I can run on 110 volts. The A66 motor doesn't
appear on any NEMA motor charts I could find. Does anyone know of a
suitable replacement motor and its frame #? I posted the same
question a few weeks ago and nobody responded, although there were
bunch of interesting (and helpful) threads going on at the time.
Tj
(18870) |
| Undermount or
horizontal drive? 1/2 HP is plenty big for these lathes. You need to
measure the mounting bolt patterns. Then look at a reference like a
Grainger book for frame info.
http://www.grainger.com/Grainger/static.jsp?page=resourcecenter.html
http://www.grainger.com/Grainger/static.jsp?page=rc_nemafmgd.html
dennis
(18872) |
| Dennis,
Horizontal drive I didn't mention that in the previous post.
Tom (18873) |
| Tom- And once
you find the price on the one in Grainger, contact me and I have one
you can have for 1/2 of that. Jeff
(18874) |
| You
can run virtually any common 1/2 or 1/3 hp 110 volt motor on a 9".. The
backdrive frame is very adaptable to any motor.. I don't bother with
all the NEMA frame data. If it has a frame with 4 holes it will fit.
Personally I only buy garage sale motors for all my stuff, never paying
more than about 10.00. I have used such a high end motor on my 9" for
about 4 years with no problems. When I dies I have a similar
replacement ready to go. (18875) |
| I just bought
a 3/4 HP motor from Northern Hydraulics to put on mine. Cost about
100 bucks and change. The shaft size requires a bushing and the base
plate requires some drilling and tapping. You may or may not find
one that matches the shaft and footprint of the old one exactly.
Probably cost you double the hundred buck number though. (18876) |
| I like your
method, but I have some questions. Are all motors reversible? Is
this accomplished by altering the wiring? I'm asking because I have
a 3 phase motor presently, and want to exchange it for something I
can run on regular house current. How about a wiring diagram? John (18878) |
| Go here for
diagrams
http://shop.emotorstore.com/estore/TD_Schematic_Diagrams.asp?
Many motors, but not all, are reversible. I bought a 2 HP capacitor
start compressor motor from HF. It stated "Not reversible". This is
seldom true. Your typical house current motor must come to a
complete stop before it can be reversed. These motors have a
starting winding. This winding determines the direction of rotation.
Once the motor starts, the winding is disconnected by a switch
(centrifugal). The motor runs on the run winding. Changing the
direction of the motor requires re-connecting the start winding.
This can be done with the same switch you have on the 3 phase motor.
However you must allow the motor to stop before reversing it. This
however is very good practice. It reduces strain on the lathe and
stops threaded chucks from spinning off and rolling across the
floor. Jim B.
(18883) |
| 9 in Motor
Selection |
| I recently
received a 1953 9 inch swing model A lathe and found the old motor
to be full of steel chips and falling apart with corrosion. This
lathe is a horizontal motor drive. I also have the 9 terminal
cutler-hammer drum switch that came with it, this is in great
condition. I would like to be able to wire it to the switch so the
spindle will go in reverse, unlike it is currently wired and the way
my heavy ten is wired. What type of motor would you recommend? Henry
(19931) |
| I
bought from Grainger when I needed a new motor for mine. 1/2 hp is
recommended for the 9". Anything more is kind of a waste of power.
Anything the lathe was designed for can be accomplished with 1/2 hp.
Make sure you get the motor with full duty cycle, reversing, sealed
for machine tools. Paul (19934) |
| This subject
keeps coming up. There are as many answers as there are SB-9 owners.
1100 to 1750 RPM, (as low as 1/3) but generally 1/2 to 3/4 (perhaps
a full 1) HP. If you want to get fancy get either a 3 Phase motor
and a phase converter or a VFD. Some owners like DC motors with
speed controls. Keep looking in the thrash buckets. a lot of washing
machine/dryer motor turn up there for free. The washing machine
motors are usually two speed. sometimes an advantage. DC motors can
be found on defunct thread mills along with controllers. Its all a
matter of what you want and how much you want to spend. The one on
my lathe was scrapped, it had a noisy bearing. 23 years later it
still has the same bearing. Remember that a capacitor start motor
must come to a full stop before it can be reversed. A 3 phase or a
DC motor can be reversed without stopping. Consider that this WILL
put additional strain on your lathe and that the chuck can EASILY
spin off and cause considerable damage not only to the lathe but to
the operator. Also consider why you feel the need to reverse the
motor. It is of use when threading, to be able to run the tool back
to the starting point without disengaging the leadscrew. It is of
use to put a tool on the far side of the cross feed, although
putting an upside-down tool there is pretty much equivalent. It
should not be used for a "quick stop". Jim B. (19935) |
| With
9 so the 1/2 HP capacitor start motor. 110v
(19943) |
| Cleaning
out my files last night, I came across a 1956 SB lathe catalogue in
mint condit. They shipped these originally with 1/2 horse. They put 1/2
horse on the 10k as well and that's what I did when I put a new motor
on mine, but I am sorry now that I didn't go 3/4. I would advise the
3/4, even though the 1/2 is perfectly adequate. It just lacks a little
"oomph" Frank (19950) |
| I keep hearing rumor that an olde-tyme
horsepower and a modern one for electric motors are different, the
olde-tyme one being a somewhat stronger horse. Then I hear that, No,
that's false, but the olde-tyme motors tended to have heavier
windings, modern ones being closer to the "bleeding edge". Bottom
line is that where Grandpa used a 1/4 horse in 1929, we use a 1/3
now, and so on up the line for fractional HP motors. So subbing a
3/4 for an "olde" 1/2 makes sense. I've got a modern 1/2 on my 9"
now, and a 3/4 over in the corner in case the 1/2 proves weak. All
rumors, of course. Dave
(19959) |
| [snip] When I
took the 3/4 HP 3 phase off my 40's vintage 10k to the motor shop to
get a new single phase one, without seeing it he said a 3/4 would be
fine. After seeing it he said "you need a 1 HP". Joe
(20007) |
| Heavy 10 motor
replacement |
| I have recently
acquired a SB heavy 10 complete with taper attachment. The lathe
came with a 3 phase 1 hp motor which I will replace with a single
phase motor. I have a 1 hp motor with bronze bearings however the
oil caps would be on the bottom since the motor mounts upside down.
I also have a ? hp motor with ball bearings. What are your thoughts
on using a ? hp motor on the heavy 10 for hobby use? The current
draw would be a little less and I am not doing production machining
where I need speed so I can take smaller cuts. Both motors are
reversible. So would you use the 1 hp or the ?. Ray
(20239) |
| For
hobby use, 3/4 HP will work fine. As to the oil holes, you may be
able to unbolt the end bells from the motor and turn them over (I
mean rotate 180 deg.). You will have to check that the wiring will
permit it but usually you can do this. Webb
(20248) |
| Webb,
I did look into rotating the end bells but the wires are not long
enough so I would have to splice extensions onto them. That
operation may injure the 30+ year old insulation so I hesitate to do
it. Also the ? hp is a TEFC motor so it is chip proof. Ray (20254) |
| Ray Years ago
I dealt with a similar oil cup problem by welding up a new U shaped
bracket to hold the motor via the long studs which hold the end
covers onto the central core. I had to replace the standard studs
with longer ones (use screwed rod of suitable size from wherever you
can get it) so that the nuts would screw on properly. I think I used
1/8 or 3/16 steel sheet for the bracket. Sure looked funny having
the motor with its feet up in the air but it worked fine for several
years until I sold the lathe. Naturally this was a 3/4 horse single
phase with the oil cups arranged for hanging down operation which I
wanted to use the usual way up. Another possibility which just
occurred to me is to mount the motor on a flat plate big enough to
run long columns up past the side of the motor and fix those onto
the mounting bracket. Given that it can be a right faffle getting at
the back bolts when fitting the motor doing it this way might be
easier 'cos you could fit the columns first and offer the motor up
afterwards so all the nuts are underneath where you can get at them.
Even simpler would be a pair of flat, U shape, straps with the tops
bent over. Bent over tops bolt to the mount, long bottom sides go
under the motor feet. Probably easiest to get in with the strap bases
running along the motor rather than across. Need to be pretty hefty
material to stop it flopping about tho', 1" x 1/4" at least I'd
guess. Clive
(20262) |
| Ray, When you
had the end bells off, did you check to see if the starting switch
could be unbolted from the end bell and reattached after rotating
the end bell? Some of these starting switches can reversed.
Alternatively, you could just replace the insulated wires
completely. It isn't that hard. You just have to trace each
insulated wire back to its connection on the coils (or capacitor)
and cut them off and solder a new lead on. There are stick on
numbered labels used by electricians that can be used to keep the
numbering on leads straight. Lastly, if you can rotate the end bells
90 Deg.s, so that the oil holes are pointed out to the side, you
could fit some Gits elbow oilers. Gits makes elbow oilers in many
size and in both threaded and press-in mountings. Webb (20280) |
| Webb, This motor
has a thermal breaker across from the starter switch so the casting
is not symmetrical, but it’s a mute point now. I installed the
? hp totally enclosed motor and it is working great. I faced and
turned an old adapter plate to fit a 6” 3 jaw I picked up and
am about to drill and tap the three holes to bolt the adapter plate
to the backing plate. The adapter plate, which threads onto my
spindle, has 3 5/16-18 holes but I think I will change them to
3/8-16. I am debating whether to drill and counter bore the backing
plate for the cap-screw heads or just tap the backing plate and let
the heads stick out behind the adapter plate. Ray (20297) |
| Motor Choice
for 13" SB? |
| I've got this 13"
I'm tearing down, fixing, repainting, etc. and it came with two
motors. The one that was mounted and running it is a Chinese 1 hp,
single-phase, 1725 rpm. It also came with a good Leeson 2 hp, 1725
rpm, three-phase. The SB data sheets for this lathe say it came
originally with a 1 hp motor. After reading some other posts about
how older motors were actually stronger than newer ones, especially
the Pacific Rim imports, I'm wondering if I'd be better off mounting
the 2 hp Leeson and building a static phase converter and getting
maybe a real 1.3 hp out of it than using the Chinese 1 hp and maybe
getting something less than that. Also, the Leeson is TEFC and the
Chinese is ODP so the Leeson is chip oil-proof. I'm not really
interested in a VFD and I can build a phase converter easily. Power
supplies/wiring, etc. is no problem. When I built my shop, I
over-designed all wiring, panels, breakers and can easily run 220V
or heavy-duty 115V to anything. BTW, I've used the same static phase
converter on my Millrite vertical mill for over 15 years without any
problems whatsoever. So, the question is - is going to the Leeson
worth the extra time and money? Ed
(20270) |
| No brainer,
go for the Leeson. Lots of Chinese motors are sold rated on the input
power consumption converted to hp and are very inefficient designs
as well. Some of the cheaper 2800 rpm ones will barely deliver half
the rated power and will stall out if you look at them. If you
haven't got the specification leaflet you won't know. Last time I
was conned the leaflet said 3 hp input, 2 hp output and the output
horses were pretty small too. In general older motor designs have
much better torque overload recovery than modern ones so they don't
stall out so easily making them seem much stronger especially on
loads where power needed falls off faster than revs. This
characteristic is basically dependent on the diameter of the
squirrel cage rotor, bigger is huskier. Older motors tend to be
larger in diameter than modern ones hence the reputation for being
stronger. Flip side is that motor efficiency is higher for smaller
cages. Modern motors tend to be designed for best power consumption
at the rated load. Small and modern could easily be using 10% less
electrickery than big old. Clive
(20271) |
| I have a 13"
with the original motor and static phase converter. Unless you are
going to turn anything that will use a lot of power (4" Dia 5 foot
long tube) or something that requires a lot of torque, you will not
miss it. (20276) |
| Heavy 10 Motor
Change? |
| I just bought a
1975 Heavy 10 with an underneath motor drive on a cabinet. The motor
requires a 208v, 3 phase supply. I've been told that I can buy an
electronic phase converter to supply the 3 phases, but I'm wondering
if the 208v is a problem or not. Would it be simpler and cheaper to
change out the motor to one requiring 110v or 220v single phase? I
can supply either 110v or 220v. Is there a reason to go with one or
the other? Also, are there rpm issues that must be considered?
(20485) |
| Look in the box
that supplies electrical to your air conditioner. If it has 3 fuses
or a place for a third fuse, you have 3 phase. If so, compare the
cost of running a line from there to your lathe vs. a phase
converter vs. the cost of a motor. If you plan to add any additional
3 phase equipment such as a mill, 3 phase would be great. You should
read the earlier posts concerning Variable Frequency Drives as that
is another way to run three phase from 110 or 220 and get variable
speed in the bargain. Also, I believe there are comments about the
torque loss from phase converters. (20497) |
| The simplest
and cheapest way is to put a 1hp single phase motor in the beast.
Its a frame 56 and wire it up for 220v operation. It is 1725 rpm
nominal motor operation. I got a brand new 1hp Leeson motor on Ebay
for $50 and put in in mine, works great. JP (20520) |
| I agree, I
put a ? hp totally enclosed motor in mine and am running it on 115
volts and it works great. I had to rewire the barrel switch to
reverse the starting winding connections but that is not difficult
and it is covered in the files. Ray(20526) |
| When I got my
10L it still had the original 3/4 hp., 3 phase motor, so I bought a
new dayton 3/4 hp., 66 frame motor. Bolted right in, all I changed
was the switch wiring because I wired it 110.
(20530) |
| Since I posted the
question I came up with another question. When I called
LeBlonde/South Bend to find out the date my lathe was shipped, the
person I talked to told me if I change the motor I should get one
with a "Soft Start". Is that a common feature on motors now
available, and should it be labeled as such on the data tag?
(20538) |
| Soft start,
easy start, or slow start is usually a function of a motor
controller. The controller starts a motor with gradual torque so it
doesn't t snap the drive train. This also limits the starting current
and supposedly increases the life of the motor. For single-phase
motors, capacitor start motors have more starting torque than split
phase or shaded pole motors but it is harder to find the later two
in 1 hp. Ray (20552) |
| At a
reasonable price you are limited to capacitor start. Starting torque
is not an issue, you have a B size Vee belt off the motor and a
leather belt off the counter drive. Most machining on the lathe will
be under 300 rpm spindle speed. You will appreciate the torque
generated by a 1hp single phase. The original was a 3/4hp 3 phase
motor. Motors were rated a bit different 50 years back. JP (20568) |
| South Bend 9A
Motor Voltages |
| I am purchasing a
SB-9A 'precision' lathe with under-drive and sheet metal cabinet.
Kind of 'special' and both bit inconvenient to me is that the unit
is 'American' or 'English' and not Metric as we are used to in
Europe. The motor currently runs on 380V 3ph. but when looking at
the motor tag it seems to 110,220 400 V. I think this unit may have
been an 'army' version that had a multiple voltage motor to have it
shipped wherever needed without worrying about power supply. Does
anyone of you know whether these units ever have been supplied with
this type of motors ?? and help me with a wiring diagram to have it
re-wired for 230V single phase? Piet (21989) |
| Can you find out
the actual nameplate details, especially the frequency (50 or
60Hz.), also advise what supply you have available? An Inverter will
allow you to run a 3ph motor on 1ph. and will have side benefits, if
you can afford it. Jim (21992) |
| You would probably
be better off just purchasing a replacement motor. I can get used
ones in the USA for US$20-40. It should be at most twice that in
Europe. Gene (21994) |
| Piet, If you can
get the manufacturer's name and the model number from the motor, you
should be able to get any info you need. Mario (21996) |
| Piet, If the motor
is 3 phase it cannot be run on single phase and generate enough
torque to be useable. You need to change the motor to a single phase
motor or feed the motor you have with 3 phase power. JP (22001) |
| JP, With a phase
converter, I believe you can run a 3phase motor on single phase
service not at full power, granted, but reasonably effectively.
Mario (22027) |
| A phase converter
actually creates three phases. A static converter takes the input
power, converts it to DC and then makes a 3 60 Hz signals or 3
phase. These cost as much as a new single phase motor. A dynamic
converter uses a larger 3 phase motor to create the third phase.
There are cheating converters which are just starter caps in series
with one of the windings of the motor. The motor will run but it
won't have much mechanical power. These are cheap but useless. JP
(22030) |
| Piet I don't think
your motor will re-wire to single phase, occasionally one of this
type will but they are very rare and usually so marked as extra
capacitors are needed. Best option, as it is a 3 phase, is to get an
electronic variable speed inverter. Much nicer to use and, for a
smaller motor, not vastly more expensive than a good quality single
phase replacement. If you want to convert to metric I suggest you
source good used Boxford feed screw and dial parts from the UK and
make the minor modifications needed to fit them. A Boxford 100/127
metric conversion gear will also be needed. Ought to be possible for
around € 200 or less. A metric converted English S-B is
actually easier to use for screw-cutting than many nominally fully
metric lathes! (22033) |
| Gee, I wish I had
know that before I built a rotary converter from a three phase
motor, and capacitors that came off scrapped air conditioners and
compressors at a local recycling center. Even worse, I've been using
it to power my Yates-American wood lathe that has a 1/2 h.p. 3 phase
motor. I've been using it for about 5 years, doing some VERY
aggressive turning, and never even noticed that it didn't have any
power!?!? I apologize for the sarcasm JP, but when people making
blanket, absolute statements, even though they are based on fact,
they can be very misleading, unless you know all assumptions that
the statement is based on. I know that a three phase converter
doesn't really develop "true 3 Phase" power. (At least that's what
I've read... I am by no means an expert in electrical equipment) I
have also read that when run on this type of power supply, a three
phase motor does not develop full power. (if you listen to the
"experts", the estimates I've seen vary from 50 to 75%). But it is
also true that this can be a very cost effective way for a home shop
machinist to obtain and use a quality machine tool that he or she
might otherwise not be able to afford. I suspect there is more than
one person on this group who is operating a 3 phase machine tool
this way, and are quite satisfied with it's operation. With regard
to the reduced power, remember that many of these machines were
designed for industrial use, with a safety factor. Even at 50% of
the original power most home shop applications will never exceed the
available power. Again, I apologize for the sarcasm, but please
let's all be cautious of making absolute statements. As Abe Lincoln
once said, "Be careful of the words you speak, for, tomorrow they
may be the ones you eat"! Mario (22053) |
| No problem Mario.
The rotary converter is another animal all together. The cap start
and cap run 3 phase motor becomes the generator of the third phase
and is probably the best way to generate it. I use it here. The
trick is to have a larger motor as the generator than the one used
to power the tool. Ideally there should be a start cap and run cap
and centrifical switch and the system should be balanced for optimum
efficiency. The rotary converter needs to be started and come up to
speed first. I didn't want to get into a long explanation before. My
intent was to warn not to bother with the 'el cheapo' power
converters which seem to be peddled by many of the Asian tool
peddlers. I do not want the get into a 'how to build it' rathole,
been there, done that. I know NOT-TING! Schultz The static converter
that I previously mentioned and the rotary converter do produce true
3 phase power. Each one can cost a couple of hundred bucks list. It
can be cheaper to buy a single phase motor. The capacitor ONLY does
not produce 'true 3 phase power'! If it looks like a motor or has a
circuit board and some big transistors inside you are probably OK,
if it just a capacitor or two (looks like a small can) don't bother
wasting your time and money. JP (22056) |
| Just to back-up
what Clive said previously with reference to the motor, To convert
it to single phase you need to find out if it is wired in the
windings to 'star' or 'delta'. On a modern 3 phase motor this is
easy, by looking in the terminal box there are 6 terminal posts with
3 link plates. For 230 volt operation, the coils are connected in
parallel (or across in pairs), for 460 volt operation they would be
linked in series (all the posts on one side connected together. In
an older motor the 'star' joint is internal so you need to go into
the motor windings and find the 'star' joint, separate them and
extend each to the 3 posts in the terminal box. Once the terminals
are set correctly you need an in-line capacitor to make the whole
thing work. If you are taking this route find an electrician, it is
dangerous to get it wrong. The second suggestion is a better
although more expensive route. A frequency inverter gives you
ultimate control of the motor with very little loss of torque, a
single phase supply running a 3 phase motor. With the use of a
remote, this allows controllable speed up and down the range at each
belt or gear position and also excellent reversing. I will be going
this route when I get an inverter I have the motor waiting. I know a
few people who have been machine operators for a number of years and
that use the inverter method and they sing its praises as a god-send
to any machine control use, they have them fitted to lathes, mills,
shapers and drills. Terry (22061) |
| I converted a
Record wood lathe about two years ago it was a Brooks 1ph. flange
mounted motor with a long shaft and four step multi vee belt pulley.
VS was the aim, changing the motor would have been expensive Staying
with 1ph would have limited the bottom speed and complicated
starting. So the motor was rewound to 230V. 3ph. and operates to
1800rpm @ 60.5Hz. and to 2625 rpm at 90 Hz. Changing the belts
optimizes the performance at the lower speeds, otherwise it is
usually left at its last setting. Control is by an old Dictaphone
foot switch modified to provide start/stop. Forward/ reverse and
speed controlled at a wall mounted panel. Speed is preset by a pot
or three binary coded toggle switches. Acceleration is ramped to
minimize inrush, dynamic braking is available but was not
incorporated - yet. I used a T.B. Woods inverter operating from
240V, 1ph.60 Hz (22067) |
| Model 9A motor
replacement |
| I need to replace
the motor on a model 9A and have no idea what the specs are. This is
reversible and runs on 110V. Can someone tell me what HP and rpm I
should be looking for ? And where a good place to buy one might be?
Ed (22360) |
| If an older
(several decades old) motor anything in the 1/2 to 1 HP range should
work fine. If a more recent model something around a 1 HP is needed.
On the older motors 1HP = 1HP. On today's motors 1HP = something the
marketing department made up. As to a source - contact me off of the
list g Dayton motors a couple of which appear never to have been
used. Otherwise Ebay is a cheap source. If you want to buy new I
recommend Graingers. They're the most expensive but the service and
support is fantastic. You might want to consider adding a variable
speed control. This used to mean switching to DC but supposedly the
cheap AC control units work well for motors up to 1 NewHP. I should
be finishing up my AC system this week and I can let you know how
well it works. Assuming the controller works well the main downside
is that you have less torque compared to using the reduction
pulleys. Gene (22361) |
| Ed, the factory
motor is 1/2 HP and 1725 RPM continuous duty, 3/4" shaft.
RichD (22362) |
| How are you doing
this and what is inexpensive? I spent the weekend reading about
VFD's and the consensus is that, while VFD's can be powered from
single phase, they will not work on a single phase motor. There are
some new units that will not but the least expensive one I found was
$300. While its not a SB and a bit OT I would like to use one on my
second Burke #4. Any suggestions would be helpful. Jim B. (22365) |
| I bought a GE 1725
1/2hp reversible motor at our local farm store about $140.00. I also
bought a version of the same motor for another machine from
www.grizzly.com for 1/2 as much but its made in China. The GE is from
Mexico. Bob (22367) |
| You are correct
they are expensive. They are commonly used on 3 phase motors because
that is where the biggest market for them is. If it is going to
double as a static converter then it might be worth the cost.
Consider a DC motor. I have picked up new ones on Ebay for $50 and
the drive for $20. The other thing to consider is, do you really
need one or is it just posh to have a VFD? I only use 3 speeds out
of the 9 available to me. JP (22369) |
| It is being done by
modifying a dimmer control. Under US$50 total. I've read positive
results but want to see for myself. Graingers has one for $150. Gene (22372) |
| You can have a real
VFD for $100 on ebay. Check item 3856062636. -- usual caveats. Some
cheaper ones are available that use higher voltages or have less
capacity. A VFD will work or can be made to work with a single phase
motor but if you have it slowed down very much it's likely start
vibrating due to the torque pulses. A three phase motor running at
20 cps is getting as many pulses as a single phase at 60 cps so
vibration wont be as noticeable. I'm not so sure of the one Gene has
found. From the description it doesn't sound like a true VFD.
Personally I'm still in the low tech world of swapping pulleys. John
(22377) |
| Check out
www.surpluscenter.com
Good source of motors and lots of other stuff. (22379) |
| We have a similar
source in Canada.
http://www.princessauto.com Dean (22380) |
| I found an
agricultural 1 hp motor in Harbor Freight for my 10" heavy and it
works fine on 110volt with the original reversing switch that is on
the Lathe. Gene (22382) |
| The motor on my
1946 model A is a Dunlap 1/3 hp, split phase ball bearing motor sold
by Sears, Roebuck. The spec plate indicates 1750 rpm 5.4 amp. The
number at the bottom of the plate is J1 46 which I believe is a date
code. I am second owner of this particular lathe, and I have every
reason to believe the motor is the original motor, and it runs like
it's new. As for power, belts slip before the motor bogs down. James (22383) |
| The link only
points to a fan or universal motor control. A true VFD will start at
around $200. While they accept single phase input, a true VFD can
only control a 3-phase motor, as the windings can better respond to
varying of the Hertz. A single phase induction motor, designed for
60 hz really hates being run on 50 Hz electricity as it throws off
the timing of the pole switches needed to sustain motion. I have a
European mill, and it shipped with a permanent split motor, because
PS motors don't mind a changing of the input Hertz as induction
motors. The mill now has as VFD and three-phase motor. There is no
torque loss when using a VFD if you stay within a given HZ range.
For example, my VFD drive has full motor torque between 20 and 60
Hz. Torque rapidly decreases above 70 HZ. The expensive "vector
flux" type have full torque from 0 to 60 HZ, as torque is a factor
of RPM. Gabe (22405) |
| The Grainger is
used for PSC motors. not what one would use for any torque on
starting. I tap on the lathe enough that I need the power. Dave
(22650) |
| But as was noted,
1/2 hp is not what it used to be. My 9" A had a 1/4 motor on it.
Sleeve bushing on the pulley end that is worn with nearly 1/8 inch
play. I would like 1/2 to 3/4 for the replacement. Has there been
any discussion of 110 vs 220 ? as regards power ? Dave (22651) |
| I just check out
Griz and they offer both open and TEFC. both my lathes are open, but
I always felt a TEFC would be much better. Wadda youse guys use ?
Dave (22652) |
| Another option is a
motor rewinding shop. Check your phone book. I picked up a nice
1/2hp for $25. JP (22653) |
| I have a 10" Heavy
with a single phase, 220 VAC instantaneously reversible motor. (yes,
single phase) Go with 220 as it uses less AMPs and thus your
electric meter goes slower. (although on a small lathe that may not
be a really big issue, esp. in a home hobby shop versus a
production plant). Eric (22654) |
| Dave, Yes, I should
have added Cap start. Mine is original 1946, even had the SBL marked
V belt at one time. This is all the power one needs on a 9" lathe.
120 vs 220 on a 1/2 HP motor is really just what ever is convenient
to you and the wiring condition and configuration at your site. It
makes no diff to the lathe operation. The start winding is 120 only
anyways. RichD(22655) |
| Eric, SORRY, BUT
THE WATT HOUR METER WILL SPIN AT THE SAME RATE. Power is power. 110
V at 7A is identical to 220 V at 3.5A. HP and watt hours don't
change. BTW, you are required to use the same size wire in the home,
so there is no change there either. RichD (22656) |
| I think that the
220 balances the load automatically so it is possible there will be
some slight savings just from the efficient use of the power. Not
that any more or less is being used. Second, residential wiring it
typically 12ga for receptacles for 20 amps, to in that area, there
is no benefit. Adding a dual circuit breaker would offer a slight
additional cost, but not much. I was thinking more on the lines of
more torque or something with the 220. Dave (22657) |
| I use TEFC whenever
I can. MUCH easier to clean any oil off and no danger of chips or
oil in the windings or centrifugal switch. I think this is more of
an issue for the horizontal drive machines than any other. Ed
(22658) |
| Nope, no savings.
The biggest expense is in panel space. (22660) |
| Dave Quite often
fractional HP motors were TENV in 70's and later. HTRL shows the 9A
as only needing !/4 HP?. The life and frame size of a motor depends
on the type of insulation it is wound with, look for type "B"
insulation as a minimum. If the motor was mfd.in compliance with
NEMA stds. then it is designed to run at maximum load, in max.
ambient for 7yrs. before the insulation deteriorates to the point
where it will no longer withstand the normal transient voltage
surges This is not valid for frequent starts, but 9A lathe service
would not be a problem as far as starts are concerned and sustained
runs at full load are impossible in the application. So 9A lathe
service is well within the designed capacity of a NEMA design motor.
It is more likely that the motor will fail due to lubrication
problems if it has sleeve brgs which are common for fractionals.
Many orig. motors are open drip proof and even assembled with the
air ducts upwards begging for swarf to enter and cause shorts in the
windings. Most rewind shops will use a better insulation than
original, therefore if the choice is yours get an enclosed motor and
if you have physical room I would recommend the largest you can fit
in the space and handle electrically, prob. 1/2 - 3/4 HP. The larger
motor will better handle interrupted cuts, carbide tools etc.
without significant loss of rpm. It is possible that the generous
motor design of the 1/4 HP, the available space and the motor cost
had a bearing on the original SB 1935 motor selection. Hope this is
of some interest and help to you. Jim (22665) |
| I tend to lean
towards "open drip proof" motors. I have used then for over 20 years
on my lathe and never had a problem. A TEFC will work just fine but
usually they are more expensive. A TEFC motor has much heavier
windings than a open drip proof motor of the same horse power
because of the poor heat dissipation of the motor. The internal fan
has to transfer heat to the case and the external fan has to
circulate air over the case to remove that transferred heat. This is
much less efficient that circulating outside air through the motor.
These heavier windings add to the expense of the motor. I have read
somewhere that a 1/2 HP TEFC motor is built to the same internal
wiring configuration as a 1.5 to 2 HP open drip proof motor. Of
course, TEFC motors are safer in hazardous environments where
explosive solvents, gases or combustible dust is present. If you are
running a coolant system on a horizontal drive lathe, then TEFC
would be the way to go. Otherwise, I would stay with an open drip
proof motor. Webb (22666) |
| The windings in a
TEFC motor are generally identical to an ODP motor the difference is
that an ODP motor would be capable of a 15% thermal service factor
and the TEFC zero service factor, no more torque, no difference in
electrical power. Which means that in a small lathe application, in
the usual ambient temperature and ignoring neglect, lightning etc.
the ODP might last 60 yrs. and the TEFC motor only 40 yrs. If you
were as old as I was before I got a lathe: who cares? With either
motor you might expect about 150% torque short time overload
capacity with about a 10% loss in RPM Providing your wiring and
power system will support it. Your ODP motor will be capable of
longer short time overload, but in a lathe with the recommended
motor I doubt if you would ever know the difference. These
statements are not valid for Oriental motors, my opinion in that
regard would favor a used NA motor especially if it has new bearings
and upgraded insulation. After an hours running, If can barely keep
your hand on the outside of the motor it is not being overloaded. If
it growls, your too late. Jim (22677) |
| I looked at the 1/4
hp motor I have that came with the lathe. Unfortunately, it is a
sleeve and not roller bearing type, which is why it is having
problems the sleeve is worn. I am thinking about re-sleeveing it,
but I have not found any data on the web regarding how to do that
and if it is advisable. I have an old HF drill press motor, looks
tiny in comparison, but would serve if I just wanted to spin the old
motor armature to grind the shaft or to make a new sleeve. I'm not
sure if there is enough room in the cast housing to install a roller
bearing. Maybe one day when I do castings, I'll make a whole new
end.... I do have a treadmill that looks interesting, have not
pulled the electronics out of it to see how it might be used. It
says it is a 2 hp motor, has a variable speed drive and is listed as
90 volts DC. I have no idea of the starting torque of such a
motor.... odd that there is so little on the net about rebuilding
motors. Dave (22682) |
| Dave Talk to your
local rewind shop about new bushings and grinding the shaft they
will probably do it more efficiently. Or better still sell you a
recond. motor with some type of warranty. Or take your chances on
EBay. If you have a controller already, the DC motor. would be the
good choice, subject to some reservations- Is the field permanent
magnet? - Is it separately excited shunt. - Is it Compound wound? -
do you have the controller to match the motor. At 90Vdc the motor
will draw 19 - 20 Amps when developing 2 HP but at roughly 1/4 HP
demand load it will only draw approx 3.5 A or a little less than a
1/4 HP single phase motor at full load, it all depends on the
starter. Local codes and insurance coverage will require wiring to
support the motor nameplate Amps. If you answer the questions posed
above I would be better able to help. Whose make is the motor,? the
controller? Are they NA. What is the DC motor frame size? what is
the AC motor frame size? The 90 V usually means it is a PM shunt
motor and the package was arranged to be plugged into 120Vac outlet
supplied from a devoted breaker. If the Treadmill is 10 yrs or so
old, it likely would meet all your needs except reversing, and this
could be easily done in a separate toggle switch or similar device
in the armature leads and interlocked with and arranged to be
operated before the motor can be energized. Jim (22689) |
| I read the label
wrong, it is 3/4 hp, 8 amps. I have not salvaged the control panel
and motor from the machine. I want to do it carefully so as to not
ruing anything that will be needed. There are a lot of selection
switches on the operators panel with multiple settings. I'm hoping I
can get it so that I have a pot and a power cord. As I get deeper
into the disassembly, I'll ask more questions. Dave (22690) |
| Dave That's more
like it. With 2HP I did wonder if it was a Elephant Treadmill. Where
are you located? I'm in Toronto. Was the TM in a hospital, a
Cardiologist's office or just a Gym? The one in my Cardiologist's
office is quite sophisticated. I'm sure the drive is separate from
the instrumentation. I have a friend who services TMs. I may be able
to tap that resource. Jim (22691) |
| Where are you
located? I'm in Toronto. The one in my Cardiologist's office is
quite sophisticated. I'm sure the drive is separate from the
instrumentation. I have a friend who services TMs. I may be able to
tap that resource. I was lucky enough to get this one curbside. The
belt looks brand new and there is no telltale dust under that would
indicate much use. Not removing any of the covers, the lower end
looks like there is a small circuit board with a few pots and a
relatively small transformer. I'll be taking lots and lots of
pictures before I open it up. I find that having about 17 different
angles on each thing, it is easier to re-assemble. If there is much
complication, I may be in over my head. if it is separate boards
then the pot may just be a remote connection to the power
controller. Heck, even if I can get a single speed out of the thing
it would be neat. I am interested to know the torque curves of such
a motor. Since it is rated at 3,300 RPM I would like to get it to
run at a lower speed. In peeking thru the holes, I did find one that
may have been the killer. There is a hole that looks kinda torn up
and inside of that the circuit board is damaged. More to follow.
Dave (22694) |
| Dave The TM motor
you have is most likely shunt characteristic, but with a relatively
sophisticated controller (before the holes appeared). The treadmill
application would require controlled acceleration therefore the
motor would not require the typical drives have some type of
controlled acceleration to protect both the motor and the equipment.
NC lathe axis drives have very high accel. rates but are designed
for that duty. Trying to start across the line is not advisable. If
your TM motor is shunt at 90Vdc for 3300 rpm then it will only
require 49 Vdc to run at 1800 rpm. The problem is that your !/2 HP
will then only be rated at 0.27 HP. Your simplest solution might be
a step down transformer to 50Vac, a powerstat and a full wave
rectifier bridge, always starting at low voltage and manually
turning it up to the desired rpm to avoid commutator damage. Jim
(22710) |
| Leemme see if I
understand. Create a simple unregulated power supply for around 50V
DC. Power it from a amp rated variac and start at a slow speed ?
Then using a DPDT relay, again of rated voltage, connect the motor
wires for a FWD/REV switch. If it is that simple, I'm THERE ! Dave
(22711) |
| I haven't been
following this discussion much, but there is a place where you can
usually find either new or take-out treadmill motors. They usually
have some of the specs there too. It may be of help.
http://www.sciplus.com/ C
(22712) |
| Bingo! Since the
motor is actually rated 1/2HP at 90 Vdc. FLC would be about 5Amps.
Full load torque will still demand 5 Amps at 50Vdc for 0.27HP at
1800rpm. So size elements and wire to support 5A. Jim Waugh (22714) |
| My background was
heavy industry. I have only a "clinical" interest in treadmills.
Your comment is appreciated never the less. Jim (22715) |
| Full load torque
will still demand 5 Amps at 50Vdc for 0.27HP at 1800rpm. So size
elements and wire to support 5A. Darn, and I just tossed about a 150
pound power supply, huge transformer and huge inductor with huge
caps... I think it was a 50 amp power supply, would have been
perfect. I have a 20 amp power supply capable of being wired for
anything from 7 volts up to about 70 volts, but the cap is limited
to 70 volts so the 40 volts would be easy enough to do. I stated
pulling apart the electronics. half of the unit is a serial
connection for different programs. running up and down hills for
different times and such. The display is in MPH, but I may be able
to use that for RPM of some reference. If I can use the electronics,
I'll go that route, but will put together a simple power supply
anyway. I'd like to put one of these on a drill press. I really want
a reverse for when I tap on the drill press. Dave (22716) |
| Interesting,
they have a 1.5 hp so, if the speed is reduced, then the power will
be reduced also, that means it would be more powerful than the one I
am looking into. I may also look into a jackshaft arrangement to get
the full motor speed and a lower lathe speed. that would be more hp
to the lathe. Interesting thread. Dave (22717) |
| Dave One more
goodie, I find an Ammeter handy on a lathe. Mine is an old ac moving
coil instrument connected in the line between the Variac and the
rect. bridge but it is scaled 0 - 150A It is a 5A movement and would
otherwise be used with a 150 - 5A current transformer. My motor is a
1/2 HP. 5A. 90V so 5A is full scale. Reasonable overload is OK say
Jim (22719) |
| It looks like
that my earlier statements were in error. I talked to a engineer
over at Reliance - Rockwell Automation and he informed me that in
large HP motors, there is a difference in the gauge, core length,
rotor size, etc. and that if the end bells of a TEFC motor were
replaced with ODP type end bells, the motor would be capable of
higher HP output. BUT in small fractional HP motors, the difference
is "Practically nothing at all..." But there can be a difference in
price. I was looking at Dayton motors and the prices for 2 HP TEFC
were about 20% higher than ODP of the same HP, construction and
frame size but some of the smaller 1/2 HP motors didn't have any
significant difference in price at all. The only time I ever had
problems with an ODP motor was many years ago on my father's table
saw. There, sawdust would get into the contacts for the start
windings and I would have to blow them out with compressed air and
the saw was good for another two (or more) years (ah, the days of
youth). Anyway, my apologies to the group. Webb (22726) |
| My motor is a 1/2
HP. 5A. 90V so 5A is full scale. Reasonable overload is OK say
continuously. For the ammeter, it uses a shunt ? no ? For AC one
would use a current transformer, but DC needs an actual measurement.
I have a few different gauges, some are really neat, some the old
round style, some are the newer square style. But, it sounds like a
neat addition. With the variable speed I think a RPM meter is called
for as well. I'll put that on the wish list too ! Dave (22731) |
| Dave In the circuit
discussed the rms current from the variac is directed through the
armature (inductive load) via the rectifier as unidirectional pulses
(not true DC) but don't tell the motor and it will never know. Jim
(22734) |
| ummm....
transformer (Variac ?) to a bridge rectifier = choppy DC waveform.
Add a filter capacitor or a inductor to get a filtered DC with close
to peak voltage (not RMS) with a cap, it is 1.414 times RMS AC (less
the bridge voltage drop) for the inductor it is almost RMS voltage
level. If I put on a variac as the transformer, or use one before a
transformer and then use a fill wave bridge rectifier, I get a
choppy DC voltage, if I add a cap, I get a smooth(er) DC voltage.
I'm confused as to which style Power Supply would be best. I already
have 10 a 10 amp variac and a 10 amp 110:48 xfrmer and a 80,000uF
100V cap so I have all the parts to do it any way but with a
inductor (choke) as the filter. Dave (22736) |
| I just pulled all
the guts out of the treadmill and found a DART controller. This is
just the ticket. It takes all the fancy gizmos out of the picture
and they are all replaced with a simple 5k pot ! With this simple
set-up I lose the speed regulation feedback from the hall-effect
sensor, but that went thru three separate PC boards. Unfortunately,
the model that DART lists does not cross reference to the label on
the unit. Seems the DART-150 controller is not listed on their site,
which leads me to believe it is an OEM unit. I hope it wires up like
the 125 controller as it appears to be very similar in many ways.
Anyone have any idea about this thing ? Dave (22744) |
| After a little
playing with the unit, I put on a pot and get simple speed control,
but there is a fixed ramp speed. I'm not sure just how much power it
will have while ramping. Since I tap on the lathe, I need that low
end torque. I'll have it on this weekend so it will be nice to spin
the lathe again after the 6 month hiatus. Since I have not found out
if will be any low end torugue, the jury is still out if this is an
upgrade, or if it is just another wasted effort. Dave (22762) |
| Dave, all the Dart,
KB and Minaric drives I've seen and used use back EMF feedback from
the motor to control speed and maintain torque. These are great and
almost bullet proof drives. Surplus Center sells Dart drives. Does
your have the 4 mini pots on the board for min speed, max speed,
torque and comp? RichD (22763) |
| It looks just like
the 125 board. yes, it does have the 4 pots. In a very crude, slow
speed test, it was pretty easy to slow the machine down with my hand
on the flat belt. Not promising for slow speed use. Dave (22765) |
| Dave, you should
try adjusting the comp and torque pots. That's what they are for! A
similar controller by KB Electronics is used in all Sherline mills
and lathes with a DC permag motor. Full torque at all speeds. I am
running a Sherline 5400 mill CNC today engraving and milling. RichD
(22767) |
| New Motor? |
| I'm not really sure
what I should do... Purchas a hole new motor (110v 1HP or greater)
or build a rolling phase converter. I know you don't get full power
out of a static phase converter, and there may be other drawbacks to
using a static phase converter, But I wonder if the same power
concerns hold true with a rolling phase converter? But
anyway...aside from the power loss or gain. What is the pros and
cons of the three configurations? Yeah 110v would be convenient, but
somewhere in the distant future I am likely to get something else
that is three phase. I guess I could always upgrade the three phase
motor to a faster model and use a VFD? I guess that adds a fourth
option. Really. What do you folks recommend and what has your
experiences been? (22985) |
| With a rotary phase
converter, it will run at full power. I made my own Rotary Phase
Converter and it cost me about $150 with a 5 HP Three phase idler
motor. Jim (22987) |
| If you visit junk
yards, you should find a junked 3 phase motor without much problem
and in decent condition. Since a rotary phase converter is easy to
make, that would be my choice for a larger lathe. If you buy new,
then you need two 3 phase motors. Also, from what little I have
read, get a larger idler motor, like a 50% larger one than the drive
motor. The single phase option is easier of course. Grizzly and
Harbor Freight sell sell motors for under $100.00. Dave (22994) |
| If you have a
true static phase converter then you will get full power from your
motor. They cost a couple of hundred dollars. A new single phase
motor is a little cheaper. I picked up a 1hp Leesom single phase
motor on ebay for $50. A rotary phase converter is a larger 3 phase
motor plus starting capacitors and run capacitors etc. They work
well. The rotary phase converter has to be up to speed before you
start your lathe. You will get the same power from your lathe motor
with it that you get from a static phase converter. There are
capacitor boxes which go cheap and are sold as static phase
converters and they are really not. These don't allow you to get
much power from your motor. A true static phase converter has a
printed circuit board and some large transistors in it. A VFD is a
static phase converter that allows you to vary the frequency to vary
the speed. This is the most expensive solution. JP (22995) |
| Go with the single
phase, it's the most flexible since it's available everywhere. New
and used motors are plentiful and reasonably priced. It will also
increase the value of your lathe should you ever decide to part with
it, given that those interested in it would likely be ones with home
shops. A phase converter will likely cost more than a motor and use
additional power, although that usually isn't a real consideration
in a home shop. However a rotary converter will also make noise as
it consumes power! As in most cases, less is more. Roy (22996) |
VSD can be had from
E-Bay for less than $200.00 so if you already have a motor, this may
be a cost effective solution. Dave
(22997) |
| A rotary phase
converter is a larger 3 phase Dave/JP , if you use the VFD to reduce
motor speed , what happens to the motor o/p torque ? One of the HUGE
benefits of the c/shaft system (or [back]gearing , equally ) must be
that as speed at point of use is dropped , the applied torque is
automatically INCREASED (ie exactly what you want ! ) . My cheapo
electric hand-drill has trigger-sensitive speed control , which is
great for starting , BUT when the speed is reduced the torque goes
out the window . Does it reduce speed by chopping the waveform , and
therefore the available power also ? Also, are there any guides out
there for rotary converters? I know zilch about them . Are they S/P
motors mechanically strapped to 3/P alternators, or is that being
daft ? Tim (23000) |
| Not necessarily so
A new 1 HP 230 single phase to 3 Phase VFD can be had for about $160
I built my RPC using a 1 « HP e-bay motor I got for $25. then the
shipping added about $20. I got 12 dual caps for $17 the shipping
added $6. I needed a box. A 10 by 10 by 12 electrical box went for
about $20 at the electrical store. I use a push button to start it,
(cheaper than a relay) $6 at HD Needed wire and crimp lugs. By the
time I was finished it cost just under $150. Not much of a
difference and you get speed control with the VFD. I am going that
way on my second Burke. BTW a usable 1 HP VFD went on e-bay for $50
Jim B(23003) |
| The capacitor type
phase converters only start these 3 phase motor. It still runs on
single phase but only 23 power. The rotary type uses another 3 phase
motor of equal or greater hp to generate the third phase. It also
uses capacitors to start the 3 phase generator motor and after its`
running the 3 leg is connected to your lathe motor. I would use a
single phase motor just for simplicity. It's not all that expensive.
(23004) |
| Tim, The motor
speed is proportional to the frequency of the drive signal, the VFD
generates the drive signal and the frequency is adjustable. The
torque is directly related to the motor efficiency at the operating
frequency, usually less than full speed but not as bad as the light
dimmer type you mention which chops power. There is no
motor/generator like the old WW2 dynamotor. The rotary phase
converter is a larger (150% to 200%) 3 phase motor which runs off of
capacitors. It in itself does not run with full torque but it does,
by its own mechanical motion generate the third phase so a smaller
motor can run from it at full power. The converter and its load are
wired in parallel. This is why the converter has to be up to speed
first to work. It is nothing more than a 3 phase motor, a start
capacitor bank and a run capacitor bank and a switchover relay. The
switchover can be manual. A RPC can operate more than one motor
providing that the total load is less than the RPC rating. JP
(23005) |
| This has been very
helpful. I am just going to purchase a 110v motor. But now the
question is how to wire it in? (23006) |
| You also asked how
to wire. What do you have? Magnetic starter or drum switch?
Momentary push button control? My Heavy 10 had the original Furnas
mag starter and momentary switch bank still installed. By using the
original Southbend wiring diagram available here and the motor
wiring diagram available from the manufacturer (Marathon motors), I
was able to rewire the starter single phase. The only portions of a
mag starter that are voltage sensitive are the magnetic coils
themselves and the "heater" fuses. The mag coils are, by definition,
single phase and can usually be wired for 220 or 110. 440 machines
usually have the magnets wired 110 and use a voltage reducing
transformer. The heaters can be bypassed if you buy a motor with
internal thermal protection. Otherwise you would need to size the
heaters appropriately for your new motor. You need double 3 circuit
mag starters to reverse a 110v motor and double 4 circuit starters
for 220. An add-on microswitch safety interlock may or may not be
needed to prevent simultaneous starter activation. If both starters
close, you short out the circuit. For 1hp or less, a drum switch is
easier. Also, 1hp is the absolute max you can run off a 110v 15 amp
circuit. If it would help, I could post the wiring diagram I used
here or at my website. Regards, Bill PS- got the new capacitor (4
bucks at an electronics surplus store) installed and my Heavy 10 is
running now- I am a very happy camper. (23007) |
| Wiring info in the
files section. JP (23008) |
| I have read with
interest the many submissions on the subject and have the following
comment. For the homemades, where did the labor costs go? At the
very least it would have an impact on the time available to read
your E-mails. What about terminals, hardware wire? What about feeder
cable, breaker and starter for the 5Hp? What about circuit
protection for the 3ph. output.? What about gas and car expense
traveling to junk yards? What about workshop real estate value? What
about fire insurance risk? What about increased power cost? What
about non-operating power cost when lathe is not running? It seems
to me the VFD has a considerable edge even before considering its
many technical advantages. You can use 1ph. input. The Ampere rating
of the power transistors has a bearing on the unit cost. The 3ph.
rating of a unit will be larger than its 1ph. rating. 120V. 1ph.
will draw more current than 240V. 1ph. and may put you into a unit
with larger power transistors. But you should use a 240V. 3ph. motor
or get your 120V.1ph. motor rewound to 240V. 3ph. - Much better than
a new oriental motor to vacuum cleaner ratings stds. You will get
rated torque to 60Hz. motor speed You can get rated HP. to 90 Hz.
motor speed. You will get low voltage control for - start, stop,
reversing, variable speed control. Programmable ramp up to set speed
(minimizes voltage drop during starting). Limited ramp down unless
you add dynamic braking option. Digital read out of performance and
faults. In my opinion the VFD has it hands down! but make sure it
has C/UL approval. Jim Waugh (23011) |
| The files section
needs a little housekeeping. Also, when you buy the drum switch, it
will (should) offer a wiring diagram. I think the wiring has to do
with how the switch needs to be wired. Relays can be used, but are
typically not a good idea unless you have an interlinked two speed
or reversible contactor. There is always the possibility of one
relay being stuck closed and the other creating a dead short. Dave
(23017) |
| Are we talking
logic or some deep rooted need to be among the bits and pieces of
mechanical inspirations that others call 'junk' ? Long ago I learned
that problems go away when you throw money at them. But part of the
fun of a home shop is making the pieces we use. There is no doubt
that I devalued my 9" by using a treadmill motor and DC drive. I
will probably e-bay it in a month when I catch up on the back-log
and then buy a new Grizzly or some such. If you have a clean and
neat shop, the VFD is the clean and neat way to go. First class,
with plugs or a contactor, you can run different machines as well.
The rotary is the second best way as it offers the most power, but
also costs more to run. But, I think the watts are somewhat
proportional to load ? idling, it uses much less than when loaded ?
As for the cost of visiting a junk yard, to me, it would be .. cost
of trip, $9.00 cost of scrap $25.00 rummage among history ?
priceless ! Besides, there are often neat things to be found. I got
a 6 ft length of 1/2 ACME for $1.00. Dave (23018) |
|
Motors/controllers: too many choices |
| Having spent the last year scrounging (rather
successfully) and jumping on a few eBay specials, I am now faced
with an embarrassment of riches in the area of variable speed motors
and controllers. But I'm not completely clear in my own mind how
best to deploy them to my lathe, my mill, and my drill press, and so
would ask here for any thoughts or advice. 1. I have a 9" SB located
in basically a hallway. There is SO little room that I cannot use
the stock large intermediate pulley (that's driven by the motor and
drives the flat belt pulley shaft). Instead, I have a 6" diameter
pulley, which is ALL I have room for. With the tensioner applied,
the pulley clears the wall by about 1/4". With the tensioner
released, the motor strikes the foot of the bed, with the pulley now
being about 1" away from the wall. The motor in question is a 3/4 HP
DC motor, with variable speed controller. My strategy has been to
set the flat belt for the lowest speed option. In combination with
the smaller intermediate pulley, this results in an RPM roughly
comparable to the highest speed of a stock SB. That is, my lowest
speed matches a stock SB's highest speed. When lower speeds are
called for, I simply reduce the speed of the motor. This strategy
has worked quite well, EXCEPT for the fact that the motor is a PM DC
motor, and so attracts chips like crazy. I've built a shield around
it, but even so, some swarf gets through. I'm worried that one day,
the swarf will get somewhere electrical it shouldn't, with bad
consequences. 2. I have a Burke HMill located in an alcove about 36"
wide and 36" deep. Getting to the back of it is almost impossible,
and even getting to either side is _really_ tough. (Too much crap
stored on either side. Long ago, I ran across a 2.5 (fake) HP
treadmill motor, running at 4300 RPM at 130 volts. I slow it down to
roughly 1500 RPM through a belt and pulley arrangement, then slow it
down some more, to about 300 RPM, via another such setup. Final
speedup or reduction is via the stock pair of Burke pulleys. Of
course, even with all of this reduction, the spindle is still
turning too fast for large cutters, so then I'm back to the
KBElectronics DC motor controller to slow it down some more. This
too works OK, but I just don't like all those belts and pulleys and
I especially don't like the motor, not for a moment believing the
power rating. 3. I have a generic Chinese 15 speed drill press with
a "1/2 HP" motor about the size of a decent razor. Works fine and is
actually accessible, but again, always either changing belts or
(more usually) running things at entirely the wrong speed. So,
here's the motor/controller combinations to choose from. 1. 3/4 HP
DC motor and controller 2. another 3/4 HP DC motor and (homemade)
controller 3. "2.5" HP DC motor and controller and insane reduction
system 4. 1/2 HP VFD and either a simple 1/2 HP 3phase motor or
another 1/2 HP 3P motor with kinda integral 7.5:1 worm reduction
unit 5. 2 HP 3phase motor with matching VFD controller I'm leaning
towards a. leaving the SB alone with the otherwise working 3/4HP DC
motor b1. using the second 3/4HP DC motor on the Burke, but with
only two belt reductions (as opposed to the current 6 pulley/3 belt
system), or b2. using the same motor as above, but with some sort
gearbox to do the initial speed reduction. Sadly, the (PacSci) motor
is not a C mount, and so any of the standard gear reduction units
are not easily utilized, or b3. using the 1/2HP 3P motor with gear
unit. I almost like this idea, except that my experience with 3P
motors (with VFD) and DC motors (with nice controllers) is that DC
motors seem to have _way_ more power at lower speeds. c. using the
2HP 3P motor on the drill press. Total overkill, but it would allow
a WIDE range of speeds while still providing lots of power for
largish drills at low speeds. d. maybe using the 1/2HP 3P motor on
my 6" AAMCO shaper or maybe my 4x6 bandsaw. As I said earlier,
an embarrassment of riches; any thoughts appreciated. Alan (25105) |
| As far as DC motors
are concerned you need to understand the Torque/Speed relationship.
Motors develop their maximum power at half their rated speed, at
zero and max RPM they produce no torque, following a bell curve. For
a better understanding look at the write up at this site:
http://lancet.mit.edu/motors/motors3.html#powercurve If you have
set your pulleys so maximum motor speed occurs at the lathe's
maximum RPM, depending on which model 9 you have that will give you
680 max. The lowest gearing, depending on the model you have, will
be 50 RPM, this is a ratio of about 14:1 and your 3/4 HP motor will
deliver less than 1/10th HP at that speed. True, the controller will
try and compensate by increasing the voltage as the load comes on,
this will increase the current flow, however at that speed there
will be little to no fan cooling and the motor will run hot. I use a
VFD on my BP look-alike mill, and it is fine if I take very light
cuts at the lower speeds, but it is impossible to take a heavy cut
without engaging the back gear and bringing the motor to somewhere
near it's correct operating point. Bernard R (25107) |
| Bernie, That is
input power consumed with a light load. The maximum mechanical power
output from any motor is at the max rated speed. To properly match a
motor to a machine you need to know the resistive and inertial
loading of each item in the drive train and match them accordingly.
As they become further removed from each other them you need to
consider a controller to compensate for the difference. The torque
is directly proportional to the current and the speed is
proportional to the back EMF or voltage generated by the movement of
the motor armature. This should be equal to the applied voltage. If
you have too small of a motor for the load then you will get
overheating. JP (25110) |
| I find the
statements on the site you posted essentially correct but somewhat
misleading, in that the implication is that the motor itself is the
determinant of torque. DC motor torque is a product of magnetic
field density and radial leverage on the armature. In actuality, the
load is the determinant of applied torque IF THE SUPPLY VOLTAGE
REMAINS CONSTANT. At zero rpm no back emf is produced so current is
limited by the DC resistance of the windings and the internal
resistance of the source. Torque is therefore at a maximum, BUT no
energy is transferred to the load. With no load, rpm is limited by
the balance between back emf and frictional resistance within the
motor itself, and again, NO energy is transferred to a load. Applied
torque is determined by the load, not by the motor. This is an
important concept. By not recognizing this essential fact, the
lesson that load must be matched to motor capability in order to
obtain maximum efficiency is not clearly illustrated. This phenomena
is analogous to the same in electrical circuitry, in which the load
must match the internal resistance of the source in order to
transfer maximum energy. In fact, it is an electrical transfer of
energy, in which the electrical load resistance is determined by the
physical load. When this is clearly understood, it becomes
intuitively obvious why maximum energy transfer takes place in the
midrange of the graph, because max energy transfer in an electrical
circuit takes place when the source and load are matched in
resistance. Jack F(25121) |
| Jack, The
intent of my original response was to advise the original poster
that there were inherent problems with depending solely on a motor
controller to obtain useful power over wide machine RPM range. I
agree that the site I listed takes the simplest view of the
relationships and does not explain the family of curves obtained by
varying the voltage. The site also does not go into heating effects,
which is the crux of the problem, when dealing with high torque at
low speeds. Your point on maximum energy transfer is well taken.
Bernard R(25129) |
| I think I may not
have asked the right questions first time around. I had no hope of
getting "lots" of power (whatever lots means) over any kind of wide
range. I was looking for something like about a 4:1 range with
"adequate" power, adequate again being subjective; I'll derate
appropriately when running slower than that. I do not think of my SB
as a particularly rigid machine; about 1/3 HP seems like an adequate
amount of power. Therefore, a 3/4 HP motor running at 1/4 speed
_seems_ like I'm still in the ball park. I understand that
electronics can't hope to replace an actual gearbox, given that when
low speed is called for, high power is also usually called for
(especially when milling). And a couple of quality computer fans can
go a long way to keeping things cool. Perhaps I should rephrase the
two questions in my mind. 1. Assuming industrial quality motors and
controllers of similar capacity, at (for the sake of discussion) 1/4
rated RPM, what has more power; a DC motor with SCR controller (and
back EMF compensation) or 3P motor with VFD ? 2. Someone told me
once that he got a better surface finish when switching his single
phase motor out with a 3 phase motor, the theory being reduced
torque fluctuation per rotation. I wasn't sure I believed it,
thinking belt stretch and inertia/flywheel effects would swamp out
any such fluctuations. But I never forgot the comment, and am now
wondering about it again. So here's the questions. Is a 3p motor
likely to result in measurably or visibly better finish than a
single phase ? And is a DC motor likely to be better or worse than a
3P? Alan (25132) |
| Alan, In the
commercial world the tendency is to go with VFD rather than DC for
variable speed, because it is newer or because it is better, there
is no definite answer. Each application has specific parameters and
all designs usually result in compromises. Better finish with 3
phase vs single phase? At full motor speed that statement would most
likely be BS, VFD vs scr control with an AC motor at slow speeds you
may see a difference because of the poles in an AC motor, not with a
PM DC motor. You are correct on the belt flex/inertia compensation.
Choppy motion shows up more in gear driven machines. Not meaning to
repeat myself but to size a motor to a machine you have to match the
motor inertia to the reflected load inertia. With a speed change
figure in the square of the ratio to change the reflected inertia,
yada, yada. Look up servo design, the same basics apply. Find the
book 'Motion Control Design' by Jacob Tal, he shows a simple step by
step approach. When in doubt, overkill with the motor. Hence a 3/4hp
to 1hp motor on your lathe and more inertia for a smoother finish.
Need a hard decision? Ok, if the costs are the same and you have to
purchase new then go with the VFD and 1hp motor. JP (25135) |
| Alan, Given the
choice I would always use an AC induction motor over a DC motor for
two reasons, 1: a severe overload on a DC motor can permanently
reduce the magnetic field, 2: no need to worry about brushes. Bearing
in mind the torque limitations at slower speeds, VFDs and 3 phase
motors are great, especially on a mill. The ability to run a
spotting drill at 2000 then drop down to a few hundred for putting
through a 1/2" drill, just with the turn of a knob is real handy. In
practice I limit my VFD to twice input frequency, with the pulley
ratio I have chosen this gives a speed range of zero to 3400 RPM,
motor's rated to 5000, and back gear zero to 400. Three phase motors
run significantly quieter and with less vibration than single phase
and their torque curve starts as soon as the power is applied, as
opposed to the single phase motor where reasonable torque is not
produced until the motor reaches at least 30% of its synchronous
speed. 3 phase motors are also smaller and simpler than their single
phase equivalent as you don't need start or run capacitors or a
start relay, they will also reverse instantly. the only reason we
don't all run 3phase is the cost of installing the service. Bernard
(25136) |
| Alan, I'm afraid I
couldn't follow your logic- kind of an electric motor version of the
shell game. However, this won't stop me from having an opinion ;-)
Horsepower is a lousy way to chose a motor, in my opinion. What
matters is torque at the machine spindle. Electric motors are
essentially constant torque devices and horsepower is torque x speed
/ 550. Say you want to reproduce the rpm range of the three step
pulleys using the middle pulley and a variable speed control. Your
presently have a 1 horse motor and this is sufficient but you
wouldn't want less torque. Moving the flat belt on a heavy 10 gives
around five to one speed range. If you use the middle pulley, you
need a motor that can operate between 700 and 3500 rpm and is rated
at 5hp at 3500. One more thing, a VFD 3 phase motor will be
synchronous so it will maintain the set speed. A PM DC motor is not
synchronous and speed will vary with load. Although some of this can
be addressed by sensing the back emf, encoder feedback is the only
way to truly control a DC motor's speed. On the other hand, unless
the 3 phase motor is designed for VFD control, it will get very warm
at low speeds as the windings can oversaturate. Again, this can be
controlled somewhat by clever VFD design but is tough to eliminate.
The workaround it to limit the minimum speed. Bill (25141) |
| Alan writes: So, here's
the motor/controller combinations to choose from. --- b2. using the
same motor as above, but with some sort gearbox to do the intial
speed reduction. Sadly, the (PacSci) motor is not a C mount, and so
any of the standard gear reduction units are not easily utilized, or
b3. using the 1/2HP 3P motor with gear unit. I almost like this
idea, except that my experience with 3P motors (with VFD) and DC
motors (with nice controllers) is that DC motors seem to have _way_
more power at lower speeds. Discussing only this one issue, if you
use a combination of belt and gear reductions 'tis best to put the
belts in the higher speed part of the train. Belt drives don't work
so well at low speeds and gear drives have fewer problems at low
speeds as compared to higher RPM. JMHO Anthony (25145) |
| I see. Sorry, I
just threw in my nosy two cents because the concept that max energy
transfer occurs when source impedance and load resistance are
matched is important in every field of energy transfer, and there is
so much misunderstanding about this. Jack F (25155) |
| Jack, It is true
that maximum power transfer occurs when load resistance and source
resistance are matched. This doesn't' mean that your best choice of
source resistance is the same as the load resistance. If source and
load are equal, 1/2 power is dissipated in each. If source
resistance is zero, all the power is dissipated in the load. Bigger
is better. Glen Reeser(25162) |
| Glen, when you find
a source with zero internal resistance you will have perpetual
motion. G Maximum power transfer ALWAYS occurs when the source
internal impedance and load resistance is equal. With less internal
resistance means you can transfer more power with less load
resistance. With zero internal resistance and zero load resistance
you will have an eternally circulating current. Some of the the guys
are working on that now with the supercooled conductors, but no zero
resistance yet. Jack F (25164) |
| Jack, For a fixed
source impedance, maximum power transfer occurs when the load
impedance matches. For a fixed load impedance, maximum power
transfer occurs when the source impedance is zero ( or as close as
you can get). Increasing the source impedance will never improve
power transfer. Ed (25173) |
| Now you are into
nonsense. When did I ever say that increasing the source impedance
improves power transfer? Your statement is also nonsense: That
statement is a prime example of the popular confusion and
misunderstanding of the very concept. What you are saying is that it
is possible to draw high current with a very low source impedance.
That is true. However, what you are disregarding is the corollary,
that to increase the current the load resistance must be lowered. G
Ultimately the load must match the source to transfer the most
power. Simply increasing current with a low load resistance does
increase power transfer, that is true, but only until the load
resistance is matched to the source impedance. Lowering the load
resistance below the source impedance will continue to increase
current, but it will lower the voltage across the load, so the power
transfer actually decreases. Calculus is unnecessary. A little
simple math will do. Jack F (25176) |
| Jack F wrote: This is implied when you suggest
matching the source impedance to the load. I am not confused. No.
The model used for matching impedance is a non-ideal voltage source
(ideal voltage source in series with source impedance) driving a
load impedance. Current is (source voltage)/(source impedance + load
impedance). Note that current increases as the source impedance gets
smaller. That is the correct way to optimize the load impedance.
Increasing current through a fixed load impedance will always
increase the power without regard to source resistance. Yes.
Matching the the load to the source is the optimum way to select a
load impedance. I suggest you do the math then. With a non-ideal
voltage source, you can optimize power transfer by selecting a
matching load impedance. There is no corollary for selecting a
source impedance. Ed (25197) |
| I copied a couple
of your remarks here. "Increasing current through a fixed load
impedance will always increase the power without regard to source
resistance." This is Nonsense because the voltage must be increased
for that to happen. "Yes. Matching the the load to the source is the
optimum way to select a load impedance." Finally, a statement that
isn't nonsense. But it contradicts your earlier position. I guess we
are into a sort of contest now, and I really don't understand why
you are trying to spin something so simple into a complicated idea.
This isn't really going to accomplish anything, because you are
looking for some special case that can never exist in order to prove
some point. No matter how you slice it, a voltage source of zero
impedance feeding through a resistance that simulates the internal
resistance of a power source in the real world, the voltage will
drop as current is drawn. When the amount of current drawn from this
simulated source causes the voltage to drop to exactly half of the
open circuit value, you will find that the load resistance is equal
to the internal resistance of the source. At this point you are
drawing all of the power that can be drawn from this source. Now
changing any of the parameters in the source like the internal
resistance results in a new and different source, so that would be
cheating to win this argument. At that point further lowering of the
load resistance will indeed cause the current to increase. However
you will find that the voltage across the load has decreased and the
voltage drop across the internal resistance has increased. At this
point more power is being consumed inside the source than in the
load. Doesn't this seem reasonable to you? If it doesn't, I can't
think of any other way to explain it, and I give up. I will answer
your one point, however. Increasing the load resistance to match the
source impedance would indeed increase power transfer. I can't help
but feel that you are so accustomed to working with very low
impedance sources like an auto battery or a power line that you
never have given any thought to source impedance, much less any need
to match it for maximum power transfer. With a power line the source
impedance is only a few ohms, mostly in the wire with the plug on
the end of it, so of course you can draw much current with little
voltage drop. As for selecting a source impedance to match the load,
of course there is a ready example. It is why high horsepower motors
are run on higher voltages like 240, or 240 3 phase, or even up to
480 3 phase. The Voltage/impedance ratio in the source is selected
to match the load. Jack F (25198) |
