| Tapers (Oct 2, 2001) |
Measuring a taper (Jul 5,
2003) |
| Turning tapers with the
attachment (Feb 19, 2002) |
Tapers (Jan 10, 2004) |
| Heavy 10 taper (Jun 1,
2002) |
Morse taper chart (Feb
6, 2004) |
| Nose taper? (Jul 2, 2002) |
Back Toolpost arranged on
Taper Turning? (Mar 23, 2004) |
| Taper turning (Jul 28,
2002) |
Morse Taper? (Dec 10,
2004) |
| Taper for spindle on SB 10 Heavy?
(Dec 4, 2002) |
Interesting Taper that I cut
(Jan 19, 2005) |
| SB 13 Spindle Taper Measurement
(Dec 6, 2002) |
Taper Math, etc (Feb 5,
2005) |
| |
|
Tapers |
| I'll need a drill chuck for the tailstock, and a
live center. My question is, what size taper do I use on an old 9"?
I called SBL, and they said that it'd take either a #2 or #3 Morse
taper, but didn't tell me how to know which to use. As I'm starting
to peruse Ebay, I think that's a pretty important distinction. I'd
also be interested in knowing if there's a toolrest that I can
attach to the saddle, as I also want to use this with my
woodworking. -G-
(1675) |
| See
http://www.loganact.com/tips/tapers.htm
The large end of the taper for a #2 Morse is 0.700", for a #3, it is
0.938". Scott Logan (1677) |
| Typically the 9"
has a 3MT spindle taper and a 2MT tailstock taper (your mileage may
vary). Do measure the tapers and compare them to the numbers Scott
Logan responded with, however. SBL shows the 9" used for wood
turning, but beware that SBL also recommends that the 9" not be used
above 1100 RPM, and not for very long periods. The bearings are
great for precision, but not for high RPM. Keep 'em well oiled. You
should be able to adapt/make a wood lathe for the SB, but I haven't
seen any for sale (eBay, etc.). Paul R. (1680) |
|
Turning tapers with the
attachment |
| How do I get the
cross slide to follow the taper attach. I can't locate the binding
bolt that separates the cross screw from the slide! (3326) |
| On my Boxford (a UK
SB clone) with taper turning cross slide plus attachments the cross
slide nut is bolted to the cross slide with two Allen (hex) bolts.
These are accessible from the top. There is no peg locating it and
when the nut is free of the cross slide it can slide in a groove on
the underside of the cross slide. David (3328) |
| Heavy 10 taper
|
| With regards to the
spindle taper question, has anyone tried using expanding foam or
something similar (with a well oiled spindle) to make copy of the
spindle taper? I was thinking that if the bore were oiled and
sealed that some expanding foam could be used to make a perfect copy
of the taper which would be a lot easier to measure or compare
against other tapers. My spindle bore is something like 1.2?" and
will not accept a 5C collet. Having an actual model to measure might
be easier to use in figuring out what it is. I pulled out the motor
I had for this lathe and looked it over for the first time tonight.
Will 1/2hp be enough or should I start looking for something larger
? While this motor is single phase it's also 230, instead of 120.
I'd need something like an 8' or 9' cord to reach the receptacle for
the dryer, can I wire in a pigtail that long ? Sorry if that seemed
silly, moved most of the shop equipment around all morning then
cleaned, primed and painted the cabinet for the Heavy 10. Even with
a respirator I've got a headache will have to wipe blue dust off of
everything in the shop tomorrow. On the bright side the cabinet is
done and all my parts are piled on top of it in the shape of a lathe
once more. A pic of progress to date is attached. Dave Attachment: (image/jpeg) Image016.jpg [not
stored] (4408) |
| David, If there is such a foam I
would like to hear about. I am skeptical though. I have a 5c adapter
for mine and find it's taper to be a relatively challenging thing to
measure. I doubt you would get anything useful from something
elastic, especially if it wanted to expand when released. For
purposes of identification, I believe the spindle diameter is the
largest size that will fit through the entire spindle. It is
probably easiest to measure this at the other end of the spindle.
The chart at: http://lathe.com/images/sb_7324.gif shows a 13" lathe,
1-7/8x8 nose thread, 1.00" spindle ID, MT4 taper where the large end
of the taper would be 1.231". Plenty big to start. SB recommends 1
to 1-1/2 HP for the heavy 10. Some "1/2" motors are bigger than
others. Multiply the HP rating by the SF (service factor) to get the
max continuous HP (yes, industrial motors typically have a rating
below what they can deliver). I would guess a 220V motor is less
likely to lie about it's rating on the name plate. Be sure that it
is a 1725 rpm motor. This motor won't draw much current so wiring
shouldn't be a big issue. (4409) |
| Ed: Yes there is such a foam it is used in the
boating industry as a way to add flotation into a space on a boat
that is already built. I believe you mean spindle bore not diameter.
Randy (4410) |
| Dave, Yes, there
are lots of expanding foams that you could use to "replicate" the
bore of your spindle nose...insulation foam that's sold at home
depot, floatation foam that Randy mentioned, etc.. They probably
would even form a nice smooth skin where it was in contact with the
metal as it cured. Unfortunately, the problem with these foams are,
first, there are a lot of volatiles (gases) in these foams (it's the
generation of these gases that cause the bubbles!) and until the
chemical reaction that generates them is complete, they continue to
expand. This process can go on for several weeks or longer. Granted
the expansion slows down considerably, but it is there. So you might
have to wait a month, take the plug out, and measure it immediately.
Secondly, if you don't measure it immediately, even if the gas
generation has stopped completely, these foams have a nasty habit of
absorbing moisture from the atmosphere (humidity) and this causes
them to grow (or shrink if it looses moisture). So, again, you'd
have to measure it before it had a chance to grow or shrink from
moisture. Measuring surfaces by replicating them to give better
access is a viable approach however, and there are " castable
replicating materials" available from machine tool suppliers. I
believe they are epoxy compounds loaded with fillers to stabilize
them (keep them from responding to changes in temperature and
moisture) but they are pretty pricey! Having said all this, I think,
keeping it all in mind, one might be able to get a reasonable
replication if you left one end open to allow the foam to expand
freely, left it in place for at least several days, and measured as
soon as possible after removing the plug. In fact, if one was in an
academic frame of mind and had some time on their hands, it would be
interesting to replicate a bore of a known I.D., follow the
preceding process, and measure and compare to the known diameter.
Then continue to measure the test plug an hour later, eight hours
later, a day, a week, etc and compare the measurements. Of
course the other approach, which someone may have already mentioned,
is putting a dial test indicator on the compound, place the end of
the indicator on the surface of the taper and adjust the compound so
it follows the taper as it is moved in and out (indicator needle
does not move!) Then lock the compound. You can then chuck up a
piece of round stock and with the longitudinal feed locked, using
the compound to move the tool along the length of the taper, and the
in feed to control depth of cut, you can make a reasonably accurate
replica of the taper. It's amazing how machinists can find so many
things to do OTHER than making actual parts!?!? Mario (4412) |
| When I have to make
a chamber cast of a rifle chamber to determine the cartridge I use a
material called "Cerrosafe" which is a metal alloy that is designed
for the purpose. Cerrosafe melts between 158-190 degrees. I use a
heat gun. It is then poured into a clean lightly oiled barrel and
allowed to set which is a matter of minutes. It is then tapped out
with a rod. If left in over 30 minutes it will grow and grip and be
difficult to remove. This would be ideal for measuring spindle
taper. It is available from Brownells and carries there part no.
080-027-100. Purchase on-line at www.brownells.com This material can
be melted and used over and over. GDS (4414) |
| Gerald Were do you
do gunsmithing? didn't know there were others on here. Jim (4415) |
| I do full service gunsmithing since 1963 Clio, Alabama formerly in Sturgeon Bay, Wi.
Regards GDS (4416) |
| There are several
type of this foam. I use the insulation foam in a can from Home
Depot recently to fill spaces in a new front door jam I installed.
The foam expanded for several days and squeezed the door jam into
the door. I had to rework it so the door would fit. I found out
later that there is another type of foam that does not continue to
expand after is sets. I don't know the names. It would pay to do
some research. What about plaster of Paris? Another thing I was
thinking about (I'm a novice so don't laugh too loud) in measuring
spindle taper. Why could you not put a test indicator on the top
slide and adjust the angle so that you get zero movement as you run
the indicator across the taper? I know the graduations on the top
slide are one degree and would hard to read and may not be that
accurate but you could leave it set and mount the tool post grinder
to make a test taper that should match exactly. Would that work?
Skip
(4417) |
| David,
I have done this exact process on an old wood lathe I was trying to
rebuild about a year ago. I used "White Lighting" auto body filler.
I plugged the spindle bore with some rag about 1/2" below the taper,
generously lubed the taper with spindle oil, mixed up some filler
with a little extra catalyst and filled the bore. Filler turned
plastic fairly rapidly, and when it got to a stiff rubber-like stage
(maybe 10 minutes) I knocked the works out of the bore with a long
steel rod, and set it aside to harden. I was able to easily measure
the taper with a vernier, which got me close enough to look up the
taper in Machinery's Handbook. In this case the bore turned out to be
a Jarno taper, which was reasonably common during the 20's and 30's,
from what I understand. Unfortunately the wood lathe headstock was
also the motor whose windings had been chewed by a mouse Try it, its
cheap, readily available and accurate enough to verify the type of
taper you are dealing with. Pete (4418) |
| I'd vote for using
a lever type indicator on the spindle bore, but then using the
carriage and cross slide backed up by plunger type indicators to
collect several data points where the lever indicator reads zero -
then its just a matter of taking an inverse tangent to find the
angle to a high degree of accuracy. If you really want to cast a
plug, the appropriate material is a tin-bismuth alloy that melts at
around 280 F and has essentially zero shrinkage. Trade name 'cerrorbend'
but the same stuff is available from a variety of sources often
quite expensive but I've seen it is cheap as $8 lb from an outfit
called Ney in Brooklyn NY (though I ended up with some to fill out a
an order of other stuff to their $50 minimum, so it may not be the
best place for a small quantity). Chris (4419) |
| Actually I've been
looking for some Cerro metal. I'd like to use it to fix workpieces
to the faceplate and cast it around some of the parts I'm working on
to give me something to grab with the chuck. I figure I can cast it
around a projection in the workpiece to form a nub that I can chuck
it with, when I'm done machining it I can just melt the cerro metal
off and move on. Dave (4421) |
| Actually, I should
correct the errors in both my own post and the other one below. "Cerrotrue"
(which is what I intended to type) melts at 280 F, is composed of
tin and bismuth, has essentially zero-shrinkage, and is relatively
non toxic. It is moderately hard and brittle "Cerrobend" melts at
158 F (there is a also a similar alloy with a wider melting range),
is composed of tin, lead, bismuth, and cadmium (hence it is HIGHLY
toxic) and expands a little on solidification. When cooled at the
right rate it can come out ductile enough to be used as a filler for
tube bending. Chris (4422) |
| Gee there's been a
lot of inventive suggestions over how to measure this taper. How
about - cut a piece of thin scrap plywood to the approximate taper,
and roll up a 1/4" bead of plasticene or bluetack. Oil the bore,
stick the bead on the outside edge of the wood, and shove it in the
bore. Hey presto one very accurate gauge. If you're mega worried
about measuring over the softer surface, stick the gauge in the
freezer for a minute before measuring. Or use a soft wax instead.
Charlie
(4423) |
| David I suspect
that a direct measurement may be a better way to get at the taper
size than a transfer measurement using foam (or a low-temp metal).
You need a way to determine relatively accurately the distance
between two (internal) diameter measurements, but I can imagine ways
using a telescoping gauge, held by the compound to measure depth. I
expect a bit of thought might generate other methods as well.
However, an even easier way is to look it up. SB says that the
"small bore" Heavy 10 (they call it either the 10R or the "11/16
collet" lathe, depending on the context) has a diameter at the large
end of 1.231" (matching your measurement well) and a taper of
.623"/ft. This is in fact a Morse #4 taper. The SB spec shows the
hole through the spindle to be 1". If anyone cares, the "small bore"
13" lathe used the same taper and through hole diameter. This
specification shows up in literature I have from 1950 to 1973, so it
should cover most (if not all) such lathes. In any case I would
suggest borrowing, scrounging, or at worst buying something
(anything will do) with a Morse #4 male taper. Put some blue on it,
put it in the spindle, and be sure the blue wipes off over the whole
length. If you have to buy something, buy a #4 to #3 or a #4 to #2
Morse adapter, as that is likely to be at the low cost end of things
you can buy with a #4 Morse taper, and is something you will want
anyway (to hold a headstock center for turning between centers).
Frank (4424) |
| Were in Texas
Creek Co. but we only been at it for 28 years or so. We do just
metal refinishing like our tef-cote and stay away from full line
gunsmithing when I can. Check out our web site if you get a chance. Jim
(4426) |
| Frank, You win the
prize! In my book yours is the best suggestion yet! Mario (4427) |
| "Playin" with
gunsmithing (my own) is what got me into this little extra hobby of
mine. I'd love to do it full time, but I'm afraid I can't afford to
leave my day (night) job, or it's benefits. Brownells it pretty
proud of their stuff. (but they tend to always have "stuff" when I
need it). Matt (4428) |
| With the right type
of plastic it sounds a reasonable idea, you can at least see the
thing in your hot little hand. Using some Glass fiber resin inside a
layer of cooking film could be an answer. Are you sure the taper is
undamaged by say having a drill or collet turning in it? before you
start to get in too deep (4445) |
| Nose taper? |
| Taper education
needed: I see references to the 4 1/2 Morse taper. I've never seen
this in any charts. Is this a South Bend taper? Were the South Bend
tapers called by a Morse taper equivalent by South Bend or was this
just picked up on? Were the SB tapers just on older machines? I
don't see any reference to SB tapers in my 70s vintage catalog.
Skip (4903) |
| Skip, Search the
messages as this has been covered in great detail. I had the same
question. See the posts from Scott Logan. Joe V. (4905) |
| Skip;
4 1/2 Morse is a weird "non-standard" standard. The oddball proprietary
taper SB used has a taper rate of a #3 morse taper, very close in size
to a 4 1/2 morse taper, and is just generally a pain in the neck. I
think this goofiness was gone by the 50's or so, my 13 incher from the
'29 to '32 informational black hole period has the mutant taper. As I
haven't had a project that requires turning between centers on this
lathe so far, I've ignored it. As the bore is munged anyway, the most
likely fix will be to press in a roughed out short MT4 sleeve or some
other taper that seems reasonable for the job at hand. Another option
is to make a plate or block to mount on the face plate, bore it to take
a short piece of drill rod, and cut the 60 degree point. The block
could be remounted and dialed in readily, and the point re-cut for work
requiring greater precision than a simple dialing in would offer. If
you have a separate driver plate rather than just a face plate, this
could remain a permanent setup, with the point always locating to the
precision of the plate/spindle mating. Not as precise as using the
spindle taper, but good enough for at least the more common class of
work. Again, the point would be re-cur for work requiring that degree
of precision, and by using a standard size bit of drill rod, could
easily be replaced when (if) it becomes too short. Stan (4906) |
| Stan, If I had a
"big bore" like that I'd use a tool post grinder to clean up the
inside and keep as much through-hole as I could. I'd also make a
collet sleeve for it once I was done. I guess I'm just envious of
your big spindle. Paul (4909) |
| Paul; I wish I
had a big spindle! The older 13 only has a 1 inch through hole, and
the fun 1 7/8 -8 nose thread. I wish it was a MT5 so I could go with
a 5C insert, and measured things to determine if making a new
spindle with a larger through hole and 2 1/4-8 or 2 3/8-6 nose was
practical. Unfortunately, the outboard bearing ID and spindle gear
are too small to pull this stunt off. The existing bore has signs of
a few boring bar crashes, so it's fairly messy. Stan (4910) |
| Stan Actually, the
"mutant" taper continued at least to the 1970's for the
5C-compatible "classic" lathes, and I suspect to the currently (or
at least up until very recently) produced SB Heavy 10. Frank
(4916) |
| Frank; There
must be more than one mutant taper? The older 13 can't take a 5C,
the through hole is only one inch. It is very close to a short 4 1/2
MT, but with the taper rate of a MT3. I'll have to wander over to my
neighbors shop and measure the taper in the headstock of his 15,
it's something we've been meaning to do for a while anyhow.
Stan (4917) |
| Stan It sounds like
you are right that there is more than one mutant SB taper. The one I
was discussing is used in all of the 5C compatible "classic" lathes,
including the 10L, 13", 14 1/2" and 16". In all these lathes the
spindle bore is about 1 3/8". The spindle taper is somewhat smaller
than a Morse #5 (big end = 1.629" versus 1.748" for Morse #5), and
the taper is 0.602"/ft (same as Morse #3, but different than any of
the bigger Morse tapers). This proprietary taper has been discussed
extensively, both here and in other groups. SB did make a variant of
these lathes with a 1" through hole, at least for the 10" and 13"
sizes. Actually I believe these 1" through hole lathes preceded
their big bore sisters. The 1" bore 10" lathe was designated the
10R, and was very different than the (later) 10K. These 1" bore
lathes supported collets to 11/16" (using #2 collets), and had a
standard Morse #4 spindle taper (1.231" big end, 0.623"/ft taper).
I have an abbreviated 1946 catalog listing these lathes, showing the
10" as model 199 (with following letters for bed length, etc. and an
8 in front for a toolroom version). For the 13", the model number
with a 1" bore is 113. This 1946 catalog does not even show a 1 3/8"
bore 13" lathe, but does show the 1 3/8" bore 10" lathe, with model
number 187 (same as the later "heavy 10" lathes). By 1952 only the 1
3/8" bore versions are shown in the catalog. Still later, in 1957,
the catalog only shows the big bore versions, but mentions in a note
that 11/16" collet capacity versions are available at reduced cost.
For completeness, both the 9" and the 10K had a standard Mores #3
spindle taper. It sounds like your still older (?) SB 13" has yet
another spindle taper, and another mutant one at that, even though
the spindle through hole is still 1". When was yours made? Frank
(4923) |
| Frank; The SB13
with the weird spindle taper here was made between 1929 and 1932,
with most folks betting on 1929. SB had a fire and lost a batch of
papers covering these years, so no real detailed info by S/N is
available. It is old enough to have a numeric ONLY S/N :-), and is a
Catalog Number 86-D. Stan (4926) |
| I run a group for
the old 10E and 10ER Shopsmith users. We have a similar problem with
serial number/date of manufacture. There are no records available
from the old Magna America Corp. that manufactured these machines
from 1947 to 1953. What I have done is collected several different
manuals (7) that show different modifications made over the years
and the manuals are dated. I can tell by the features a machine has
about what year it was made. I sent out a survey to the group
members (around 300) and asked for the serial number and whether or
not their machine has this or that type whatever, about 8 or 10
different things. I have around 85 machines in my data base now. The
problem I have that you probably won't have with SB is that there
were two different mfg. plants that used different series serial
numbers. That makes it really tricky. I thought this idea might help
you with the SB lathes. Skip (4929) |
| Taper turning |
| I want to turn
tapers, with my 9c. Every pic I have seen shows a dog plate and lathe
dog. Is that a req when using a taper attachment? I want to build a
model cannon. rick
(5436) |
| Rick, if you have a
taper attachment, you do not need to turn between centers unless you
want to. I usually use a collet at the headstock end and a dead or
live center at the tailstock to resist deflection. Just be sure to
remove the screw from the cross-slide when you activate everything!
(assuming your 9"c has a standard, and not some rare telescopic
taper attachment:^)) Turning between centers or with a collet and
center is more accurate, if very close tolerance and repeatability
for future set ups is important. For instance, I recently made a
couple modified square thread taps with long tapers. It is important
that these can be accurately registered for flute cutting, (milling)
and for grinding after hardening them. Having the center drilled,
and turning to it, makes this more convenient. One reason many shots
of taper turning show the work between centers is because the
operator is not using a taper attachment; but is using the tailstock
set-over, or tailstock mounted offset boring head method. You "have"
to use a center or ball bearing at each end to accomplish this
successfully with any more than a few thousandths taper. Smt (5440) |
| Rick; Turning
between centers isn't a requirement for using a taper attachment.
The benefit of turning between centers is being able to unmount and
remount the work without having to fiddle with marking jaws and
such. Some (most?) taper attachment work tends to be on things
requiring somewhat tight tolerances, the class of work that would be
done between centers or in collets in any case, even if the taper
attachment wasn't part of the operation. I think perhaps the pics
you are seeing are ones where the taper is being generated by
setting over the tailstock, a useful method, full of all sorts of
little pains in the rear and neck in practice. Stan (5441) |
| Rick, I just did
some taper turning on my Heavy 10 South Bend and I used a good 3 jaw
chuck (very little run out) with the taper attachment and it worked
just fine. Bob (5446) |
| Taper for
spindle on SB 10 Heavy? |
| Can anyone tell me
what the taper is for the spindle on a South Bend 10 Heavy? I'd like
to get a center for it but I'm not sure what to get - it looks like
a MT 4? Mark (7752) |
| If you look
carefully at the table, the .623"/ft taper is for the 13" lathe with
11/16" max collet capacity (i.e. the "little" spindle bore 13"). The
same .623"/ft taper is used in the little spindle bore Heavy 10",
although the table doesn't list it. As I understand it, your 13" has
the large spindle bore (what SB calls "1 1/16" collet" in the
table). so yours is identical in terms of spindle taper to the
"ordinary" heavy 10. Both have a spindle taper which is about the
size of a Morse 4 1/2 or Morse 5, but with the taper per foot of a
Morse 3 (i.e. .602"/ft.). Where SB specifies a spindle Morse taper
of #3 (as "N"), they mean the taper available after an adapter (with
the special SB taper on the outside) is inserted. I'm intrigued that
a Morse #5 fits your spindle. There have been other occasional
reports of either heavy 10" or 13" lathes where #5 fits. Are you
sure it fits well,? It is sometimes hard to feel it if a male taper
with only slightly different taper foot is put in a female taper. Do
you have some hi-spot blue? If so a good test is to apply some blue
to your #5 end mill taper, insert it in the lathe spindle, and see
if the blue shows good contact at the back as well as at the front
of the taper. I'll bet it won't (but I have lost bets before). Frank
(7760) |
| SB 13 Spindle
Taper Measurement |
| I got home
(late) this evening, I took four different MT 5
attachments I own and tried blueing them all into the spindle of my
SB13 with the large spindle. I was mistaken about there being two
tapers, there is only one. What I mistook for the second taper was
the beginning of the straight bore. Anyway, all four adapters blued
in perfectly. I measured the four (an MT5 to MT4 sleeve, two
different end mill adapters and a Royal 5C collet adapter) and
calculated tapers of 0.6156, 0.617, 0.6162 and 0.6268. These were
relatively rough measurements, but all are around 0.62, which is
near the spec for MT5 and not near the .602 shown in the SB chart.
The ,6268 was the Royal
collet adapter. All these tools lock in tightly and, as I said, the
Dykem test was perfect on all. I noted that there is a lot of
variation in length of these adapters (the taper part) varying from
1.72 inches for the collet adapter to almost 6 inches for the
sleeve. The collet adapter fits the spindle to within a few
hundredths of the nose. All the adapters are the same at the
back (small) end. The taper section in the spindle seems to be
slightly less than 2 inches long. From this, I have to state without
doubt that my SB has an MT5 taper. I really doubt it was modified
after leaving the factory, unless someone was really good with a
long nose grinder and taper attachment. Based on the contour and
finish of the taper and bore behind it, I doubt this happened. By
the way, the statement a lot of people make about MT5 adapters
sticking out of the taper a long way and therefore not fitting is
sort of off base. All the tapers except the collet adapter are so
long compared to the spindle taper that they would have to extend
out. Also, most full length tapers are so large at the big end that
if bored and inserted to the full length, there would be less than a
quarter inch of metal between the bore and the thread root. So, does
anyone think SB may have made some lathes with MT5 tapers? It would
be interesting to see a build sheet or tag on this lathe to see if
it is mentioned. (7794) |
| I find this to be
really interesting. It certainly sounds like your 13" really has a
MT5 taper. The SB spec sheet I have (I believe the same one Scott
posted) is dated 1973 and doesn't mention anything but the
proprietary taper. I wonder if yours is newer than this, and they
changed between 1973 and your lathe's manufacture date. Did you get
a better calibration on when it was made? It might be worth a call
to LeBlond, both to get the date and see if they know of MT5 spindle
tapers. Frank (7821) |
| I don't believe my
lathe is that new. It has a 10xxx serial number, which would put it
about halfway thought the postwar production. 13" really has a MT5
taper. The SB spec sheet I have (I believe the same one Scott
posted) is dated 1973 and doesn't mention anything but the
proprietary taper. I wonder if yours is newer than this, and they
changed between 1973 and your lathe's manufacture date. Did you get
a better calibration on when it was made? It might be worth a call
to LeBlond, both to get the date and see if they know of MT5 spindle
tapers. (7837) |
| Measuring a
taper |
| If you can put the
thing in question between centers and align the compound so that an
indicator does not move for some 1 or 2 inches of travel, you can
put the indicator on the opposite side and move the same 1 or 2
inches and then calculate the angle. pretty simple with no other
tools than the compound, and on that you do not need to use the
protractor. The trick is to use a dial indicator when moving the
compound on the measurement run. Since the compound is at an angle,
moving it exactly 1 inch on the dial will not be 1 inch on the part.
Dave (12513) |
| Dave the item is
the spindle bore it is stated as a #3 MT in the specs but it is much
larger than a standard #3MT as you can stick a 1 3/8"piece of stock
through it, so we know it is not a true #3MT.It is possible that it
is indeed a modified #3MT as was mentioned before, which makes
complete sense. Terrance
(12515) |
| I can't tell you
this applies to your South Bend lathe, but it might be worth looking
into. Many engine lathes have been built with maximized spindle
bores for use with through the spindle chucking, bar feed, or power
chucks. Most of these lathes have a large short taper, usually a
Jarno in the spindle itself. A spindle plug which adapts the spindle
to a standard morse taper usually comes with the machine when new.
You might inquire with le blond (who now sells parts for older South
Bend lathes) to see if South Bend ever used this method. From
personal experience I know that American, LeBlond, Colchester, Mazak
and many other engine lathes both domestic and foreign have spindles
made this way on at least their larger machines.
Rich (12516) |
| Or the 3mt spec is
for the tailstock spindle? Clint (12520) |
| I like to actually
measure things when there is any question. Also, I am not sure there
is a modified anything when it comes to things like a MT. it either
is a MT3 or it is not. a drill that is 0.5" dia is not a modified
3/4 inch drill. I have a Jarno taper that is between a MT2 and MT3.
seems like they made that just to prevent it from being used on
other machines, and to prevent other machine tools from being used
on their machine. If a 1.375 round stock can enter the large end of
the taper, it is larger than a MT4 It is can go all the way thru,
then it is larger than a MT5. Once you have measured the actual
diameters and angle, you will most likly find that they are some
standard taper. http://shopswarf.orcon.net.nz/sindex.html has a few
index sections of tapers as so does LMS
http://www.littlemachineshop.com/Reference/Tapers.php
Certainty is the absence of confusion. Dave (12522) |
| I am going to guess
it to be an MT 5 taper? Clint (12524) |
| I'm betting it is
the same South Bend proprietary taper which found its way into all
of the later (1940s-1960s) large lathes. As discussed extensively in
the past relative to the heavy 10 and 13", all of the "classic" SBs
capable of supporting 5C collets within the spindle used a
proprietary spindle taper with the same taper (0.602"/ft) as the
Morse #3, but with a much larger diameter, between a MT4 and MT5.
This proprietary taper is documented in many places in SB
literature. The difference in taper per foot between this taper and
a MT5, with 0.623"/ft of taper, is quite small, and correspondingly
hard to measure by practical means. The difference in taper is .020"
per foot, or about .0017" per inch, which is really hard to measure
on a tapered surface. Probably about the only way to be sure would
be to find something with one taper or the other (SB proprietary or
MT5) and blue it into the spindle. Even the wrong taper will feel
pretty good in the spindle, due to the small taper error,
necessitating the blueing to be sure. Another source of confusion is
that SB frequently quoted a "Morse taper" for the spindle that
referred to the inside of an adapter provided with the lathe. For
instance the heavy 10 shows a Morse #2 taper as the "headstock
center" as well as the tailstock in the specifications, which if
course is not the taper in the spindle itself. Frank (12534) |
| Didn't we go
through this a while back and agree that its a half length MT 5 with
only the small end present. The MT 3 (or 2) refers to the internal
taper of the head stock adapter. Measuring my Heavy 10 that seems
right. HTH Clive
(12536) |
| According to SOUTH
BEND LATHE CORP, it is a proprietary taper of 0.602 inches per foot,
with a gage line dimension of 1.629". See:
http://groups.yahoo.com/group/SouthBendLathePix/files/Specs_and_Tech_Info/sb_7324.pdf It is NOT a Morse #5, front, back, middle or sideways.
The Morse #3 referred to in SB sales literature is the internal
taper of the standard spindle reducing sleeve. Scott
Logan (12538) |
| Tapers |
| I cut some #3 and
#2 Morse tapers years ago using just the compound. To adjust the
compound correctly I set up a Moris taper I already had between
centers and locked the compound down when a tool point would run
along the taper when I turned the compound wheel. Gary
(16453) |
| Making a
taper is a good lesson for the novice as well as the experienced
machinist. The 3 most common methods are: 1.Replication,2.bore
setting,3.sine bar method 1.replication: Having standards in your
tool box like tapers allows you to make almost any tool on the
lathe. In this case a set of tapers that fit your lathe, drill
press, and or mill, make it possible to quickly build cutter-holders
like chucks. Chuck the taper between centers making sure they run
dead-true. Using an indicator, set the compound to the desired
angle. Keep in mind that you need to have the gib adjusted so the
tool will run smoothly without side-slop. I set my tapers up so the
big end always faces left. The blank is then turned out of some tool-steel, NOT
CRS! Even 1144 or4140 is better then cold rolled.
2.bore-matching:This is another way to attain the same result. Set
the compound off the head stock bore. Keep in mind which side you
locate from. Set the compound off the FAR SIDE of the bore. This way
you will have the blank's big end to the left. 3.sine-bar method:
This is a bit tricky. A sine-bar is placed on it's side up against
the compound. A spacer the right length cocks the bar to the proper
angle. Place the dial indicator on a long rod and use this to '0'
your sine-bar. If I recall, the side of your compound must have a
machined surface parallel to the ways. Of the 3 methods listed, this
is probably the most involved. IN GENERAL: Make your tapers when you
have no other job to distract you. Use good steel even though you
may never harden it. Be sure your cutter is honed sharp with a 1/32"
or less radius. Once you do this, you'll want to tackle other jobs
that build you tools and more confidence. Ron
(16456) |
| Further to Ron's
excellent advice I suggest that before attempting to do accurate
tapers you fake up some sort of screw controlled adjuster for the
compound or taper turning accessory. The British Standard tolerance
on Morse tapers is 0.0002" end for end (i.e. the total error between
the correct and actual diameters at the large and small ends).
Trying to set the angle to achieve that accuracy by tapping, or
pushing by hand, the compound or taper turning slide gets old rather
rapidly. I reckon that if you bolt a "U" shaped bracket enclosing
the base of the compound, with a suitable clear space each side, to
the fixed steady mounting holes it would be easy enough to arrange a
pair of fine thread pusher screws to adjust the top slide angle in a
repeatable and controlled manner. Geo. H. Thomas suggests in his Model
Engineers Workshop Manual that the top slide be serviced, lubricated
and carefully adjusted before doing fine tapers as virtually the
complete travel will be needed and any imperfections will show up in
most grievous fashion as the extremes are approached. He also
advocates fitting a dowel pin to the top slide and gib strip
preventing the strip from moving longitudinally on the adjusting
screws. Obviously this does not apply to taper gib systems, only
those with conventional side adjusting screws. I have found that
fitting such a pin and paying careful attention to the condition of
both the ends of the adjusting screws and the gib strip holes in
which they sit makes a great difference to the operational feel of
the slide and the ease with which it may be set just so. When doing
fine limit work it is impossible to overstate the advantage of
having the machine set so that it does exactly what you tell it to
do rather than having to be carefully coaxed. My mentor, the late
Robin Bacon, advocated the use of two pins to fix the gib strip
longitudinal position with floating ball bearings interposed between
the strip and the adjusting screws. This layout is often found on
high precision systems for optical instruments. I don't know whether
its worth doing to a SouthBend but Robin did this when renovating an
elderly, and sadly distressed, Portass with great success achieving
much "better than new" performance. Geo.H.Thomas also advocates the
addition of a supplementary locking screw pressing down on the gib
strip somewhere near the middle to lock the slide in position during
the cut. Locking either the cross or top slide as appropriate to the
job in hand is a great help in getting precision cuts and good
finish, especially if your feed screws and nuts are past the first
flush of youth and exhibiting significant backlash. As an aside it
should be noted that when the gib strip, dovetails and other details
are correctly attended to it is virtually impossible to lock the
slide by correct, equal, adjustment of all the screws. Smooth,
albeit mildly stiff motion still being possible at remarkably high
adjusting screw torque. Naturally excessive torque on a single screw
instantly brings things to a halt. Although dovetail wear is
inevitable on the older lathe I find that many of the deficiencies
attributed to wear are primarily due to gib strip and adjuster abuse
coupled with crud build up in the points of the dovetail recesses.
On the ageing lathe remarkable improvements can often be achieved
by:- 1) Cleaning out and undercutting the dovetail recess points
slightly with a fine hacksaw blade. 2) Putting a narrow, 1/64 inch
or so, vertical flat on the dovetail points. 3) Making a new gib
strip correctly tapered to fit snugly into the top of the dovetail
and of thickness such that it only just slides in. 4) Fitting nice
new adjusting screws with correctly domed ends engaging in decent
conical recesses in the gib strip (use a centre drill). Whilst you
are at it fit the locating dowel pin and lock screw as mounted
above. I successfully followed Mr. Thomas in using 2 BA lock screws
with an 11/16 long lever on one side, I guess 10-32 ANF is
appropriate for those SouthBends still residing in their native
land, giving about 1/4 turn betwixt lock and free. Obviously any
marks of abuse on the sliding surfaces must be removed. Another job
for the famous worn out No 6 file liberally coated with cutting oil.
Clive
(16458) |
| Morse taper
chart |
| I sell a lot of
tapered parts and am too lazy to look them up in the Machinists
Handbook. I found this chart on the net and printed out a copy to
make it easier.
http://www.morsecuttingtools.com/data.html (17065) |
| Also try:
http://www.loganact.com/tips/tapers.htm Scott Logan (17066) |
| Back Toolpost
arranged on Taper Turning? |
| Much as I
love my Heavy 10 trying to do without a back tool-post is driving me
nuts with all the changing from cutting tool to parting tool and
back. I equipped my old SB 9" with one and I now realize just how
useful and convenient having a properly aligned parting tool at the
ready all the time in a back tool-post was. Being a 2 tool turret
having the knurling tool there two was handy as well. I can't think
of any sensible way of getting a back tool-post onto the Heavy 10
without risking serious damage or loosing the taper turning
capability, but if its possible at all I'm certain one of you good
folk knows how. I think the usual trick of having an extended cross
slide casting wont work due to the taper turning attachment. Failing
that do you think that anything could be done in the way of a QD
supplementary parting tool mount latching onto the front of the
cross slide. Superficially the idea seems sort of possible but
keeping the cutting tool out of the way when parting off could be a
bear. I frequently work with the tool and top slide at odd angles so
the usual type of QC tool post will be no great help. Current
practice is to have a stock of nominal "4-way" tool posts with
suitable tool sets and change the whole post from cutting set to
parting / knurling set and back. Its quick enough, half turn on the
lever and slide out of the top slide slot, slide in the new one and
half turn to lock but aligning the parting blade square with a job
mounted up can be tricky. Clive
(17918) |
| What if you made
your 4-Way Tool Post so it was indexable with a spring loaded ball
underneath to stop it at exactly 90 Degree increments each time? Ron
(17923) |
| Morse Taper?
|
| I am the
one with the 1944 16" SBL I do not have a tailstock, and I am in the
process of getting one. I was wondering if anyone knew what Morse
taper the tailstock should have? I have some huge drills for a M5,
but I have been told that it should have a M3? Is that right or
what? (22772) |
| I think the
tailstock might be a #2MT (22774) |
| It's a #3 on our
1957 16" SBL tailstock. (22776) |
| My mid fifties 16"
SB has a #3, I would be surprised if a 16" had a smaller taper
tailstock as its the right scale size for a 16". Mark (22785) |
| MT5? That
would be HUGE for a lathe. remember the twisting forces are kept in
line with the bed and headstock. I have used a MT2 male /MT3 female
adapter to hold MT3 drills in both my drill press and my lathe, but
make sure there is a lot of meat in the hole. don't try to remove a
little sliver. Having a nice 1/2 inch pilot hole for a 1 inch drill
gives the 1" drill some room to cut. if you tried to open up a 15/16
hole, the drill will thread into the work and break something. Dave
(22792) |
| My Sheldon 13 uses
mt5 in the spindle; it s BIG!!!! Tailstock is mt3 on it. Lew
(22794) |
| Interesting
Taper that I cut |
| Yes, I measure my
piece smaller in the middle and a thousandth
LARGER at each end! It is a 6-inch piece of 1-inch diameter
aluminum. I haven't heard of this before. Is this caused by heat
expansion? I was using a new carbide insert tool, and of course
running my machine faster than I ever had before! Not even the
surface cut speed allowed, but around half of that, around 1300 RPM.
I was using cutting fluid. How do people work around this heat
expansion? Bernie (24111) |
| I'm not sure this
is what happened, but if your toolbit was a bit high of center to
begin with and your bed is worn a bit right around where it got
smaller, that might explain it. Alan (24125) |
| Very interesting.
And very possible also. It is a new carbide insert tool, and maybe
the higher RPM than I am used to cutting ACTUALLY cut accurately,
the IN-accuracies of my bed!! Not a huge problem yet, but definitely
one to solve. I will let you know. Bernie (24131) |
| Taper Math,
etc |
| I was trying
to turn a double taper (basically a wheel that tapers from the
middle toward each end). I thought I had it figured out, but
although it will work, I'm totally disgusted with the result. I was
curious if there is a way we could have a file that would give
different equations on various machining formula's. Today, I could
have used something that to give me a X diameter at one point and Y
diameter at another point, what degree or inches of pitch would I
set my taper attachment to. I learned a lot by today's experience,
but wasted a lot of time and some precious (to me) material, and
still didn't get the finished product I wanted. Does anyone else
have a tough time trying to figure out the math? I did take algebra
and geometry in high school, but that was a darned long time ago
(sine, cosine, and tangent is a different language as far as I'm
concerned). There has to be some way of getting some simple
formula's to do common layout. Dave
(24876) |
| Forgive me if I get
too basic. Lets start out by saying that usually the angle of a
taper is small. (Unless you have a big mill with one of those 40
tapers) a small angle is one that is close to zero. The sin of 0
degrees is 0. The cos of 0 degrees is one. Tapers are usually
specified in terms of the depth one cuts in inches per inch or in
degrees or in terms of the big diameter, the small diameter and the
length. If you are given inches/inch you need to find the angle to
set the compound or the tailstock or the taper attachment. Note that
on a lathe if you take 0.001 the diameter is reduced by 0.002 so you
need the half angle. Now lets say you wanted a MT2 taper. My
reference says 0.7000 big end, 0.57200 small end, and a length of 2
1/2 The taper I need, on one side, over a 2 1/2 length is
(0.7000-0.57200)/2 = 0.064" over 2 1/2". Over one inch its 0.064/2.4
= 0.026" per inch. If I am setting over the tailstock I would need
to set it over 0.064" I have never used a taper attachment so I will
defer to somebody else. If I am using the compound either I need an
angle or I can put a dial indicator on the compound an move it one
inch (allowing for the angle, here we need the cos, but for this
small an angle the difference is too small to worry about) and
adjust the angle to get a change of 0.026 or over two inches 0.052
etc. If you need an angle to start try this. Now if I knew the angle
I would multiply the sin (since the depth is small) by the length
and this would give me the depth that I would cut over 1". To find
the angle I reverse the process. I divide the depth I want to cut by
the length and that gives me the sin of the angle. I need the angle
not the sine of the angle. However there is a shortcut. For small
angles the sin = tan = angle (angle in radians) Well what good it
that I want it in degrees. You can either remember the conversion or
do as a I do and figure it out every time. There are 2*pi radians in
360 degrees. (My last post had a typo in it) so take your depth of
0.026 and multiply by 360/(2*pi) = 0.026*57.3 = 1.49 degrees. (If
you chose you can memorize the 57.3) (24878) |
| The calculator
program that comes with windows has Degrees Radians and Graduations
buttons, you can enter the angle in Radians and click on degrees and
Waalaa instant conversion. Jeff
(24880) |
| Here's my set of taper
formulas. There are four factors -- Larger diameter (DL), smaller
diameter (DS), length of taper (L) and angle (A). If you know any
three, you can figure the fourth, using one of the following
formulas: L = (DL-DS) / (2 * TAN(A)) A = ARCTAN ((DL-DS) / (2*L)) DL
= 2 * L * TAN(A) + DS DS = DL - (2 * L * TAN(A)) I use a TI-36X
calculator that I got at Costco for under $15 to handle all the
dirty work. Bruno (24881) |
| So, the answer to
David's question is either buy a scientific calculator and learn how
to use it or get a table of trigonometric functions such as the one
on page 60 of Machinist's Ready Reference, 9th Edition?
Indispensable reference book and it also has the formulas for tapers
in Section III. (24883) |
| Dave, Being lazy, I
generally draw up anything I'm going to make. Now days I use a
commercial CAD program, but just doing a quick Google I see there
are still plenty of free CAD programs out there. Doing a drawing
has, in my opinion, several advantages, first you can see if it
looks right and if it doesn't you adjust it till it does, next it
will give you a hard copy with all the dimensions, including any
angles, and then if you save it you don't have to tear your hair out
when you realize that the wife has thrown out the napkin your
masterpiece was sketched on. It's still useful to know the math to
be able to do quick calculations in the shop, but I don't start any
new projects until I've got the design down on the computer, if it's
a milling job the computer's going to be doing the job anyway and I
just drink coffee and change tools. Bernard R (24886) |
| I'm
going to take those methods and formulas, study them and try to make
sense of it. I'm thinking I need to go to the library, or research
on the internet the meaning of some of the terminology AND I could
look it up in the Machinery Handbook (16th ed), Mechanics Vest
Pocket Reference Book or Pocket Ref that I already own!!!! I'm sorry
if I wasted anyone's time....I should have done some research myself
with the reference material I had on hand, or at least done some
internet researching. I was so frustrated with myself yesterday
after screwing up that wheel that my thinking process shut down and
I took the easy way out (it really was that bad). My problem is that
I know what I want something to turn out like, and when I can't meet
my own expectations I get totally frustrated. (24888) |
| I think there are a
few amateur machinists, like me, on this users group that will learn
a little math from some of the experts. I have gone to the bottom
row of the old living room book shelf and dusted off my 1968 copy of
"Elements of Trigonometry" from my high school days. It is out in
the shop now. It is what I look at when I take a sit down break. The
slide rule is staying lost. I am getting a calculator to do the
dirty work. I am saving all the math answers in an outlook mail
folder that I called "South Bend Math". That way when I know more
about Trig, I can go back and make sure that I understand what these
guys were talking about. I think the consensus of this group is that
a frustrated machinist is welcome on this users group. And I am glad
of that. Nick (24893) |
| Dave, I did not
mean to chide you for not researching your question on your own.
Hope you did not take it that way. Like you, I passed Algebra and
Geometry but was lost in trig. I also had hopes that there was an
algebraic answer to this problem but apparently there isn't. I also
wanted to point out that there are tables that will answer the
question but, for me, I am not confident that I am using them
correctly so I have to make a drawing to scale and measure the angle
to make sure the answer is in the ballpark. Thanks to all who
provided the usual helpful and accurate information. Working thru
your explanations added to my understanding. Thanks to Dave for
asking. (24898) |
| I didn't take it
personal, I was just ticked cause I didn't think of it first. But
actually some of the answers I got looks to be easier to figure out
than the books. (24899) |
| As someone else
suggested, I have found the Machinist Ready Reference to be the most
used book I have, both at work and at the home shop. Its printed by
Prakken Publications and the ISBN is 0-9703398-0-1. Jim (24903) |
