| A/B Apron Gasket (Jun 3,
2001) |
Repair halfnuts (Jun 17, 2003) |
| SB Lathe Carriage gib adjustment?
(Aug 1, 2001) |
Non-functioning clutch on 10k (Oct 26, 2003) |
| Apron kicks into gear for no
apparent reason (Dec 12, 2001) |
Half nut repair (Nov 24, 2003) |
| Half nut restoration (Mar
22, 2002) |
9"
half nuts (Dec 8, 2003) |
| Unknown hole on end of SB9 apron
(Apr 26, 2002) |
Half Nuts and saddle questions (Dec 14, 2003) |
| 9A apron controls (Jun
25, 2002) |
SB
9A Apron questions (Jan 31, 2004) |
| Jumping Carriages (Aug 3,
2002) |
Question on heavy 10 Carriage (Feb 21, 2004) |
| Source of Bronze filings inside
Model A/B Apron (Aug 24, 2002) |
Apron worm gear replacement (Mar 27, 2004) |
| Clutch in a 9A apron?
(Nov 5, 2002) |
Apron clutch construction (Apr 6, 2004) |
| Restoring Half Nuts with a
bronze bushing (Nov 8, 2002) |
Half Nut Repair (Apr 15, 2004) |
| Sticky Clutch (Nov 25,
2002) |
Clasp nuts / Split nut SB 9" (May 4, 2004) |
| Key in Apron Falls Out!
(Dec 29, 2002) |
Worn worm wheel SB 9" (May 5, 2004) |
| SB 9A clutch assembly
(Mar 17, 2003) |
Fitting new half nuts (Nov 2, 2004) |
| Halfnut slack (Mar 30,
2003) |
Slop in apron handwheel (Jan 27, 2005) |
| 9" apron question (May
9, 2003) |
Worm and wheel drive for 9" (Feb 12, 2005) |
| |
| A/B Apron Gasket |
| In the
process of installing the carriage lock, I took off the apron and
saddle. Wow what a mess! In the years that I have had the lathe, I
never took it apart more than I had to. I think that the previous
owner used it for some wood turning: gunked up/oil soaked sawdust
everywhere in the apron, dried and hard. the oil holes in the half
nuts were plugged. I have taken off the half nuts and sheet metal
cover to the worm drive and friction clutch to get better access to
clean it in there. I put the whole thing in the parts washer and
flooded it for a while to soften the gunk. Bronze tooth brush and
toothpicks are handy for cleaning... I am missing the gasket between
the sheet metal cover and apron casting. From the parts breakdown,
it forms a well for the oil bath on the gear train Can anyone
describe it? Is it paper, felt or cork? I almost hate to find out
what SBL wants for the gasket. I am tempted to make my own. I have
some 0.030 EPDM rubber and some 0.030 cork gasket in sheet form. Is
it advisable to use either of these as a gasket in there? (775) |
| I went thru the same with
mine, I just made a new gasket from light gasket paper, worked good.
I agree on the prices from SB TOO HIGH! But available. Bob (776) |
| Yup, it
is a paper gasket. About .010" thick but you can use whatever
thickness gasket material you have on hand. Thickness isn't critical
on that cover. Just need to keep the oil in. Webb (780) |
| And remember, it's not under
pressure, so it should be straightforward. In a pinch, I used
form-a-gasket. Next time I have the apron apart, I'll probably make
a nicer one, though. Paul R. (783) |
| SB Lathe
Carriage gib adjustment? |
| I can feel motion,
maybe a couple of thousandths, when I lift the apron side of my 1969
heavy 10 carriage. As far as I know the only takeup is the two gib
screws under the opposite side of the carriage. Those do well for
the off side, and there's no lost movement there with the carriage
moving smoothly and easily. Do I live with this slop? The ways are
good, even excellent--this occurs at any carriage position equally.
Would it be OK to remove the apron and hone it's mounting surface to
bring it up and get rid of the play, or is this more or less normal?
(1242) |
| This is normal with
any lathe. Normal cutting force is down on the apron side, therefore
no need for gib control. If you wish to tighten this side up (like
when using a tool bit upside down) snug up your carriage lock a bit.
(1245) |
| Apron kicks
into gear for no apparent reason |
| I have this old
1947 SBL 9"x48" Model A lathe. For months the rig will run like a
Swiss watch and then all of a sudden like last night, I'm doing the
finishing touches on a nice little brass race and all of a sudden
the apron kicks into gear for no apparent reason. The clutch is
COMPLETELY out ( turned fully anti clockwise and then I always back
it back a hair). I then run the carriage back and forth a few times
and it is OK until for some reason a couple of months later it will
do it again. Lots of good lubricant, everything nice and clean. And
it always seems to happen when it can just wreck a sweet little job
like last night. I'd swear a invisible hand is making it move. Does
anyone else ever heard of this or know what the problem could be?
(2397) |
| As a relatively
uninformed guess, perhaps a chip is getting into the clutch and
creating enough friction to transmit torque for a while? Or perhaps
some sort of clutch material is flaking off? I tend to keep the
leadscrew off when I'm not using it, as the straight tooth gears
make a real racket at higher spindle speeds. Of course, in between
cuts it's hardly worth moving the reversing lever to neutral, so I
can see how unexpected clutch engagement would cause problems now
and then. Chris (2400) |
| I'll take your
advise Chris and take the apron apart and see if there is a chip or
a piece of whatever in there. Thanks for the info. I'll post my
findings when the job is done for future (spook hunters). (2403) |
| I always wondered
about the SB clutch. Is there any advantage to a friction device,
rather than a dog clutch? Would it not be possible for a friction
clutch to engage itself, if there was slight drag on it? (2408) |
| This applies to my
1929 SB13 apron, can't promise that it applies to other SB tapered
clutch drive aprons. My SB9 is a model C, so I can't check on that.
This model uses a knob you rotate to tighten a cone clutch assembly.
The tapered male part of the clutch revolves with the shaft it is
mounted on. There is a selector lever for power cross or
longitudinal feed. For the clutch to self actuate on this lathe,
you have to have the lever in one of the power feed positions, the
lead screw has to be revolving, and you have to get a sufficient
piece of crud into the tapered surfaces. Being a taper, when fully
disengaged, the spacing between the tapered surfaces is almost an
1/8 inch. While possible, it seems unlikely that a 1/8 inch chip
would get into this part of the apron, bounce at the just right
angle, and produce the needed drag to actually engage the taper.
Possible, but not something that keeps me up at night :-) Looking at
the PDF Army manual, it looks like the 9 uses a pair of shoes,
engaged by wedges when the lever is flipped. I notice there is a
spring that appears from the drawing to hold the wedges clear. If
this spring weakens or breaks I imagine you could get some
interesting clutch behavior. Stan (2411) |
| I thought the idea
of a friction clutch for the power feed was that it could slip when
the saddle, under power feed, hits an obstruction. This means one
could use a indexing stop to machine a series of items to the same
position. A dog clutch would not allow this. David (2416) |
| The handbook from
Boxford (UK Southbend copy) shows a set of six adjustable length
stop rods mounted on a rotatable 'turret' which is fixed to the
saddle. David (2420) |
| Well, perhaps the dog clutch approach is not quite so cut
and dried. My 11" Hardinge HLV-H uses a pair of single tooth dog
clutches in one of the slickest threading processes I've ever seen
on a manual lathe - one clutch for each direction. You can set the
end point within .001" and it will stop there *every* time as you
retrace the thread with increases in thread depth. After years of
threading at painfully slow speeds on the Heavy 10 so I could
manually release the half nuts in time at the end of each cut, it's
a rush to do it at 500 RPM or more and be sure the lathe will stop
at the right place. The method requires a small "landing zone" at
the end of the thread - you can't thread right up to a shoulder
because the spindle keeps turning when the tool gets to the stop.
The half nuts are never released during the entire threading
process. They modestly recommend keeping the spindle speed below
1,000 RPM. Mike (2431) |
| You can use such
gadgets by manually winding the saddle to the stop, which is what I
assumed had to be done. Now I'm wondering: would it hurt the lathe
to use it as you suggest ?(2436) |
| Half nut
restoration |
| I built the
fixture described in HSM for restoring half nuts. I have bored out
the old threads and now I am thinking of silver soldering a bronze
sleeve in the resulting hole to be threaded 3/4 " x 8 Acme. I have
never silver soldered cast iron. I am a bit leery of brazing bronze
as the melting points may be incompatible. Glen
(3701) |
| Soldering Brazing I
don't know what is going on here. Glen
(3703) |
| Glen, I posted on
this around January. I had mine built up with WELCO 14 BARE nickel
silver alloy. I just got my 9" running last week and the halfnuts I
rebuilt with this procedure are as good as a new set if not better.
Here are a few added thoughts in addition to the article. 1. I did
all my work on a Bridgeport mill. This procedure can be done on the
lathe as in the article but the mill setup is sturdier 2. I bored
the original threads out to .85 dia. I reasoned this would leave .05
of alloy to act as a "base" for the threads. 3. The halfnuts appear
to be made from a single casting and split down the middle with a
1/8 cutter after all factory machinery is complete. When I sized and
cleaned up the silver solder I left the center portions heavy so
there would be .005 or less between the two nuts when in the
fixture. (In the fixture the nuts are in the engaged position on the
lathe.) In hindsight I believe this step was the basis for my
threads coming out as good as they did. I'll explain. I purchased a
new tandem acme tap for this project and during tapping I had to add
clamps over the threaded portion of the nuts as the casting would
flex away from the tap. I tapped about 1/4 turn and backed out. I
did this while advancing 1/8 to 1/4 turn each time. By having a full
diameter of metal around the tap I experienced none of the
"breakout" that would have been felt with the 1/8" gap between the
nuts. Also, you can purchase a single stage acme plug tap for about
1/3 the price of a tandem. Don't even try to do this with an acme
plug tap. I think the nuts would break from the forces required to
remove all the metal with the single thread former on the plug. I
have spent the last year rebuilding my 9" and at some point in time
I plan to post pictures in the files sections so the group can see
my toys. In this was to be pictures of these nuts and the fixture.
If you have any questions feel free to contact me.
Ed (3705) |
| Glen: That's
alright it happens to us all eventually. Randy (3707) |
| One of my
students busted the gears on the lead screw's drive on wends. I
forgot which lathe that was, but believe it is one of my Clausing?
Can someone help with a source to by new/ used gears. These belong
to the high school where I began teaching this year. Boy you can
forget a lot when you haven't touched something in ten years! That's
how long it's been since I ran a lathe at SIUC! Steve (3711) |
| Glen writes: I
am a bit leery as the melting points may be
incompatible. Use a low temperature silver solder such as EasyFlo or
PhosCopper. Both melt and run far below the melting point of bronze.
Some here will not use PhosCopper on boilers because of the sulfur
products in coal fired locomotives, so don't burn coal on your lathe
if you use PhosCopper ;-) John (3718) |
| John, One of my
many other hobbies is jewelry making (let's call it investment
casting here, it sounds more macho). I was intending to use some of
the solder I use for soldering silver to silver. I have several
different grades "hard, medium, easy, extra easy". They are intended
to be used in multiple step fabrication processes where the next
solder operation uses a lower temp solder than the last. This worked
fine on the cross slide nuts I made, but that was soldering bronze
to bronze. I have never tried it on cast iron. Glen (3731) |
| Ed, My thinking was along the same lines as yours. I bored out
the old threads to about .830 and planned to silver solder a sleeve
turned from a bronze casting sprue. The extra material would hold
the two halves together during the threading operation. A hack saw
and a broken rusty file would do to separate the two halves and
clean up the saw kerf. I purchased a tandem Acme tap on E-bay a
couple of months ago and I have been itchin to try it ever since.
Glen (3747) |
| Ed, I had the same
thought as you about leaving some room for thread adhesion, but I
was also thinking that a sleeve soldered into the half nuts would
solve the problem of the two halves wanting to separate. Glen (3761) |
| Glen, Sounds like a
plan. By using a sleeve and then splitting after tapping you will
probably not see the two half's flexing away from each other while
tapping. Let us know how this method turns out. Ed (3762) |
| Unknown hole on
end of SB9 apron |
| What is this hole
for? I've got two SB9A's and both have this hole on the right side
of the apron, below the thread dial stud. Its not threaded and its
fairly deep. It doesn't show on any of the documentation I have.
Anyone know why its there? I have a Trav-A-Dial I want to mount on
the SB9 I'm keeping, and am interested in using this hole as part of
the mounting. Don't want to do any irreversible modifications.
Rick K. (4091) |
| Rick, I picked up a
9" model A HMD last Sunday. It was manufactured July 30th, 1946 and
has the same hole. Due to the position of the threading dial I
cannot see that anything can go in there. I would suggest you call
South Bend and ask for Ralph, who works in parts. Everyone knows him
since he has been there for 40 years. If he doesn't know what the
hole is for then no one does. Fred (4098) |
| Rick: I looked
at my SB9C and I do not have that hole, so maybe it has to do with
the more complex carriage necessary for the power cross feed,
perhaps an access hole of some sort. I see you have two SB9A's, When
you put up an SB9A for sale recently, I thought that maybe you had
found the SB9A qualities to have been exaggerated and you were
returning to your Atlas. From your picture of the carriage, it looks
like you found a newer one with original factory paint, looks nice,
what I can see of it. Rich (4100) |
| Very observant.
Yes, newer, nicer, better, lots of candy. Plus a very nice cabinet.
No, the SB9A attributes have not been overstated. The Atlas was/is
just taking up room in the shop and in the way. I was presented with
an opportunity to upgrade in SB9A features, etc and just couldn't
pass it up. Bought new by a school in '56, bought by a retired
machinist in mid 60s, cared for very well since. Family joke was how
well oiled it and everything in his shop was. Photo attached.
Rick (4107) |
| Rick, wish I could
help on the Mystery Apron Hole. I have a 1937 "C" Model that my
Grandfather bought new in 1937, but it doesn't have it. I've had it
since 1964. Up until a month ago, I didn't know what the vertical
hole on the Tailstock was really for. I had always used it to keep
the key in for the Tailstock Chuck. I see you do the same thing.
Now I'm looking for an original "Dauber". Benny (4108) |
| Rick: Very Nice, I
would have been tempted also. Glad to know you are still enjoying
the SB's. Its amazing how many SB's are out there, they must have
made a lot of them. Rich(4109) |
| What a Beauty!! I
nominate this lathe for the monthly poster machine!! The paint is
also a very attractive color, is it original? If not could you tell
me what it is? Pete (4110) |
| I never used the
hole at all until this one entered my shop. It was in the dauber
hole when I looked at it and I've started doing it. At least I know
where it is now. Might have to add such a hole to my 7x12. Rick K.
(4113) |
| Just sold the first
one, the one you sent me the documents for. Made a copy for him, the
beat goes on. Now just the Atlas 10F to sell and I have my shop
space back. The candy that came with this one is way cool. Now that
the one is sold, I'll take down photos of it and post more photos of
this one, on my web site. Rick K. (4114) |
| Rick, I believe
this hole is use when installing or removing the interlock pin that
locks out the power feed lever when the threading lever is engaged.
The power feed lever must (if the interlock is working properly) be
in the center or neutral position in order for the threading lever
to be engaged. I had an apron where this pin was too short and
permitted the power feeds to be engaged at the same time the
threading half nuts could be engaged. Fortunately, I corrected this
before any accidents. Ed
(4117) |
| Interesting. So,
will it be possible for me to use a 1/4 or 1/2 of this hole for a
locating stud for mounting a Trav-a-dial to the end of the apron
without interfering with anything? Seems deep enough. Threading dial
would get mounted on the outboard side. Rick (4119) |
| Guess I didn't
finish my thought on using the hole for your purpose. I don't see
any problem using the hole to mount the travel dial as long as it
can be removed and the hole cleasrs in case you have to access the
pin. Same type of mount as the thread dial maybe? Ed (4127) |
| 9A apron
controls |
| I've had my SBL
9" A for a few weeks and have been cleaning and trying to figure how
to take things apart and attempting to determine what needs
attention and what kind of shape the thing is in. Since the only
reference I have is the old book 'How to Run a Lathe' that the owner
I got it from still had, I assume this will not be a dumb question.
In the South Bend book mentioned the apron controls have two levers
and a clutch knob. In the book the carriage and cross feed lever has
three positions. One for carriage movement and one for cross-slide
movement and one for neutral. Mine has four. Two down drive the
crosslide and one up drives the carriage and the fourth one which is
the second up I cannot engage. There does not seem to be a neutral
and I am hesitant to try threading until I am more sure of what I am
doing. Jim
(4738) |
| Jim, The hole at
"twelve-o'clock" is an oil hole and you can't get the lever to it.
At "one-o'clock" is the long-feed. At "two-o'clock is neutral --
allowing the split-nut to be engaged for threading. Finally the
"three-o'clock" position is for power cross-feed. Paul R. (4739) |
| Paul, after further examination with your information I
now notice that the 12 o'clock hole is smaller than the other three
and the 2 o'clock as you put is in fact neutral. It still doesn't
look like any of the other pictures I have seen but you are correct.
I surmise from the serial number 145442 and the tag that confirms
this lathe meets War Board standards that it was made during WWII.
Imagine that. Older than me by not a whole lot and still turning
metal. I really don't have a crying need for this machine but it's
like owning a piece of history. I am going to do my best to restore
it to somewhere near new and leave a legacy to one of my
grandchildren if any of them appreciates it. I guess like other
people in this group I am a tool freak, always have been. My first
question is normally "How did they do that?". Which invariably leads
directly to what tools did they have? How did they build those
battleships with huge guns. How did they make a lathe in 1900 that
could turn and bore a 14" rifled barrel? I seem to have digressed.
Jim (4741) |
| I can't speak for
the turn and bore of the barrel, but I know the rifling was an
insert sleeve. During Viet Nam the Navy dusted off the New Jersey
and the Missouri to use as gun platforms. Both needed to be
re-sleeved and there was no shipfitter or machinist mate left in the
Navy who knew how to do it. They found a retired master chief who
hired on as a consultant to do the job and document it for
posterity. Flash (4746) |
| Jumping
Carriages |
| Folks Vertical
movement of the carriage under cutting forces can be due to lathe
assembly or set-up errors. The minions of SMAMAMT (Society for
MalAlignment and MisAssembly of Machine Tools) are ever active.
Frequently their efforts can only be uncovered by the sort of full
check out which is understandably unattractive in the excitement of
installing a new lathe especially when preliminary checks and first
cuts suggest that all is well. My recently obtained heavy 10 did a
couple of beautiful jobs on dural but turned its nose up at mild
steel. Close inspection showed that all the headstock bearing shims
had been removed and the rear thrust bearing for the crosslide
leadscrew was missing! I would suggest that anyone suffering the
same sort of problems as Mario makes a careful check of the
headstock bearing adjustments. I have always found that accurate
setting is much more important when trying to get a well finished
bore than when turning outside diameters. It is also worth checking
that the carriage is riding properly and snugly along both sides of
the guiding vee. Its quite easy for a determined meddler to misalign
the leadscrew so it either takes some of the weight of the carriage
or is trying to pull it down. Little bits of gunge, wiper felt or
even (please no) swarf can also get caught underneath which does not
help. If its been run with the back gib loose an oil bound dust/gunge
layer can build up which leaves things springy when the back gib is
tightened down as it should be. (I know a man who spent two years
nursing good results out of a 9" model C with the last problem! The
comments after a couple of hours worth of stripping, clean up and
reassembly fixed the problem were said to be "educational".) Clive (5558) |
| Source of
Bronze filings inside Model A/B Apron |
| I bought a Model
A/B apron for my model C. On disassembly and cleaning I found a ton
of bronze filings but have not been able to determine their source.
The gears and half nuts seem fine and everything functions properly.
John
(5967) |
| I'd have
to guess that the previous owner did a lot of bronze turning, there
isn't much bronze to be found in most lathes. Stan (5968) |
| Stan,
I didn't find any bronze parts inside the
apron and was hoping the filings were from turning, but the
particles didn't look like swarf, rather more like fine particles
from a worn out component. Anyway, I have to locate the appropriate
screws to complete the upgrade. There were several on Ebay when I
wasn't looking for them. It happens. John (5970) |
| Clutch in a 9A
apron? |
| Please excuse
the ignorance, but I am not aware of a clutch in the carriage of my
9A. I thought the only entities engaged when feed was actuated were
the half-nuts, engaged by flipping the lever. Please enlighten me as
to the location of this clutch. Bilal(6997) |
| The star knob,
bottom dead center. Clockwise to engage, counterclockwise to
disengage...and the lever immediately above it chooses power long
feed, power cross feed or neutral. There's an interlock so you can't
engage both kinds of drive at the same time. There's an excellent
series on rebuilding an "A" apron with lots of pics of how it works
at www.steammachine.com/hercus/ (6999) |
| Folks, I
wonder if the 9 that I have is a model A or not; for the following
reason: I don't have either the star knob for the clutch or the
other three-position lever shown on the Hercus' carriage. I am 99
percent certain I have a model A, though. All I have is the lever
for engaging the half-nuts...other than that, there is nothing on
the carriage. Is this a model A carriage at all or not? The bill of
sale dated from 1980 identifies this as a model A. Bilal (7056) |
| Bilal, Does it have
a double tumbler gearbox or a stack of change gears to vary the feed
rate? Glen (7057) |
| Look at E-Bay items
1784542127 (A Model) and 1785319432 (C Model). These should show you
what you want to know. Maybe someone swapped out the parts. Does
your lead screw have a keyway slot along it? Tom (7058) |
| Glen, I have BOTH a
double tumbler gearbox AND a stack of change gears...to make the
matter even more confusing. Any suggestions? Bilal(7062) |
| Bilal, It sounds
like you have a Frankenlathe. If you want to convert it to a "full"
"A" model, it shouldn't be too difficult. The hardest part is the
gearbox/leadscrew which you already have. Your leadscrew does have a
keyway milled down the whole length doesn't it? If this is the
case, all you will need to do is obtain an apron from an "A" model
and install it. There are 2 or three screws holding the apron to the
saddle plus the carriage stop bolt and it's "brake shoe". remove the
right side leadsrew support (have a friend support the lead screw
while you are doing this) slide off the old apron and on with the
new. You need to determine if your saddle has an opening in the
bottom for the new apron worm gear to engage the gear on the cross
slide lead screw. My model "C" Frankenlathe had a model "A" saddle,
so this was not a problem for me. You will be very pleased with the
power cross feed feature. The clutch feature is also useful when
turning to a shoulder. I am always a bit tense when using the
halfnuts for normal turning. There is no "give" in the system unless
the belt slips. I see model "A" aprons on eBay from time to time in
the $100 to $125 range. I relined a set of half nuts before I
obtained an "A" apron. The "new" apron half nuts were tighter than
the ones I relined. Since the half nuts are only used for threading,
they see much less wear. Glen (7065) |
| Bilal,
http://home.attbi.com/~wasser/SBLathe/index.html
Did you look at the E-Bay items I listed? If not then also look at :
(Damn thing won't paste stuff where I want to.) Could have someone
changed some parts on your lathe. Does you lead screw have a slot or
keyway long its length? Tom (7067) |
| Bilal If it does
not have the 3 position lever and the clutch knob, it is a Model C
Carriage/apron. Does the lathe have a QC box? Clint (7068) |
| Bilal Is the QC
gear box mounted on the lathe or is it separate? Clint (7070) |
| Glen, Tom and
Clint, I most assuredly have a "Frankenlathe." The serial number is
49584-NAP-10, which identifies it as the 49,584th 9" Model A built.
It just has a Model C carriage and a set of Model C change gears.
Maybe the previous owner had a Model C parts lathe sitting around,
and he decided to swap the carriage for some unknown reason. Tom, I
did look at the eBay items you mentioned and by seeing them, as well
as the link you provided, I decided I DEFINITELY did not have a
Model A carriage. Thanks. Clint, as would be on a Model A, the
gearbox is attached to the lathe, ie: appears to be integral. Bilal (7076) |
| Bilal You will be
able to find a Carriage/apron for it but you will need to check the
saddle and make sure it has the gear for the power cross feed. That
is all you are missing at this time is power cross feed
capabilities. Just to bad you did not get the carriage in the pile
of parts, but that's the way it goes. Be thankful you have what you
do have. Clint (7077) |
| Clint, Is that what
the three-position lever above the star knob on an 'A' carriage is
for? The power cross-feed? Bilal (7079) |
| Restoring Half
Nuts with a bronze bushing |
| Not wanting to wait
for Brett to figure out how to get into the group, I've uploaded his
description and photos of how he restored badly worn SB9 Model A
half nuts using a bronze sleeve. A short description file and two
photos have been uploaded to the FILES area.
http://groups.yahoo.com/group/southbendlathe/files/RestoredHalfNuts/ Rick K.
(7061) |
| That is a beautiful
and innovative way to handle the problem. Will have to file that
into the back of my brain for a future project that I have. I never
would have thought about doing that way. My congratulations. (7074) |
| What an innovative way to restore the half-nuts. No special welding
or fixturing equipment needed. I'll be curious to see how the repair
works over the long haul. Many thanks to Brett for the technique and
Rick for bringing it to us. Brett should have no difficulty to get into the group. Paul R.
(7083) |
| Sticky Clutch
|
| My new to me 13x40 Model CL145C. has a
sticky clutch, when disengaging the crossfeed or carriage feed it
will sometimes stick, more with the cross feed than the carriage
feed. It seems to be adjusted properly, as it engages fine and at
the proper angle according to the book. This machine has been
sitting idle for some time now, and I am thinking possibly I need to
flush the old sticky oil on the disc plates. or is this the nature
of the beast? I have previously owned a Logan, and an Atlas. however
this is my first South Bend. Thanks Dee
(7547) |
| A South Bend
Maintenance page says-- To remedy a sticky clutch. The cause of a
sticky clutch can usually be traced to dirty oil, improper oil, or
edge of clutch disks are burred. To remedy. follow the steps
outlined below. 1. Drain apron oil from reservoir and fill with
kerosene. 2. Operate the lathe for a day or two and drain kerosene.
3.Flush with kerosene until clean. 4. Refill with South Bend CE1600
or equal. 5 If clutch remains sticky it is necessary to remove
clutch assy to examine the discs. There are 15 more steps on how to
do No. 5 on this page. Walt (7549) |
| I went out and drained the oil pretty thick stuff! added kerosene
and Wa La just like you said after cycling it back and forth a few
times it already was better! after about a 1/2 hour use it does not
stick at all. I am going to leave it in there for a day, and refill
with the proper oil. Dee
(7551) |
| I am interested in
your post because you appear to have a valuable manual I hadn't
heard of. Would you tell us what publication your maintenance info on
the apron came from, and if you know about it's availability. Thanks
to the wisdom dispensed on this site I have a number of small
publications for parts maintenance adjustment for my South Bend
Lathe. I would love to add to it to get smarter about
restoring/maintaining my lathe. Mike
(7555) |
| Mike, when I
bought an SB lathe at a High School auction years ago that sold out
everything, the school guy there said to take any of their manuals
related to the machine I bought. I picked up a large loose leaf
manual that appeared to have all the data on a lot of SB lathes.
Most of it is the regular parts lists, but mixed in under maintenance
are a number of them such as the Sticky Clutch, procedure for
converting from star wheel to lever on the Apron, and changes of
installing large feed dials, etc. Since these are SB publications,
Rose at LeBlond may know of them. I may not have all of them. I am
not sure of the copywrite laws or I could copy what I have.
Walt (7558) |
| The method on
clutch cleaning is in the South Bend parts manual. It's a little
over a hundred pages. I got a copy on CD. You should also get a copy
of "How to Run a Lathe" from 1942, and a complete copy of "South
Bend Lathe Bulletins". I got a copy of all these bound in one book.
There are generally multiple copies of all these on eBay being
offered by several different vendors. Just go to the Machinery
section and look under lathes. Do a search on South Bend. Most are
available via Buy it Now so you don't have to fool with bidding.
They generally run about $12 to $17. (7574) |
| Dee I
just uploaded a PDF file in the "techinfo" file section. It is a
scan of the "How to Remedy a Sticky Clutch" page from the SB parts
manual. Hopefully this will help. FYI, I've scanned all but a couple
pages of the entire parts list/manual and will be soon providing a
link to the PDF file. Jeff (7596) |
| Key in Apron
Falls Out! |
| The 10L
I'm working on came without the keystock that connects the leadscrew
and the (don't know the name) gear in the apron. Without this, I
obviously don't have power crossfeed and traverse. What is supposed
to keep this in? Is it interference fit into the slot in the (don't
know the name) gear that goes around the leadscrew? Wallace
(8335) |
| One end of the key
has a little baby dowel pin p/n 160X19 that goes through the key,
through the wall of the wormgear, and through the nut that threads
on the end of the wormgear. There's a good explanation of the apron
disassembly/reassembly with lots of good photos at
www.steammachine.com/hercus Lurch (8341) |
| Wallace, On my 9
inch lathes there is a small pin that goes through the worm gear (
the one that is keyed to the leadscrew) and into the key that runs
in the groove in the leadscrew. The pin is pretty small, about 1/16
inch diameter or so. If your apron came without this key or pin, it
shouldn't be too hard to drill a key for a new pin. It was near the
headstock end of the worm gear as I remember. Good luck finding it!
Glen
(8342) |
| Yep--it also locks
the nut that threads onto the end of the worm, from unthreading off
the worm. (8345) |
| What holds the pin in place? Interference fit? Its' placement
in the keyway? The site where the guy rebuilds the Hercus is very
helpful - what a tale! I've decided my $350 10" Heavy was a bargain
after seeing what that guy went through! Alternatively, is there an
exploded parts diagram available on-line anywhere?
Wallace (8348) |
|
http://www.john-wasser.com/SBLathe/ (8349) |
| Wally, It was an
interference fit into the key. The leadscrew keeps the key in place
when it's all assembled. It was tight enough in the worm and nut to
keep from falling out when the apron is removed from the leadscrew.
Glen (8364) |
| I came home and
took the apron off - no hole for a pin in the keyway of the worm.
Also, my worm doesn't appear to be held in place with a nut: it
looks like there are pressed on bushings on each end that hold it in
place. I'm kind of torn now: do I try to make an interference fit
key (again) or drill a hole for a pin? The SN on my 10L (170216)
puts in in the early 40s. I wonder if they came out with the pin
design later, or if that is just a 9" and 10K thing? Thanks again
folks - I'll figure something out. Any more suggestions or info
welcome. Wallace (8365) |
| Wallace; This
may be an apples and oranges sort of thing as I have a 9 and a 13
but not a 10. On the 13 inch apron, the key is longer than the
keyway, and at each end there are ears that press against the ends
of the worm. These ears help hold the key in place during assembly,
and keep the key from sliding out of the worm, which would happen if
the leadscrew keyway had sticky oil or a bit of grunge. (8367) |
| Wally I think the
heavy 10 may approach this differently than the 9/10K. In the parts
diagram it looks like the worm key has a step at both ends which
protrude axially beyond the ends of the worm gear, such that once
the leadscrew is in the worm gear with the key in place, the steps
at the ends keep it in place. I also have a sheet from SB describing
the replacement of the knob clutch with a lever clutch. After
describing removing the apron by sliding it off the lead screw, it
just says to remove the key (no mention of pins, etc). Same story in
the instructions for reassembly. My first guess is that you may have
a key from some other lathe. BTW, the same sheet says that the
bushings at the end of the worm are threaded to the worm. There is a
pin from the bushing to the worm which maintains their alignment.
The same sheet suggests parking the relative position of the collar
to the worm gear before removal to allow returning to the same
relative alignment (although I don't understand why the pin doesn't
serve the same purpose). Frank (8369) |
| Now I see! I got
impatient and made one that is a tight fit in the worm, and put it
in place with some Loctite. Now that I hear the description of the
one from you and Mr. Stocker, it seems so obvious! If this one comes
out, I'll make one as you guys described. Wallace
(8370) |
| Any hope you'd scan
and post that lever-clutch-conversion sheet? Does it apply to the
9/10K?
(8379) |
| Wally writes: What holds
the pin in place? Interference fit? Its' placement in the keyway?
The site where the guy rebuilds the Hercus is very helpful - what a
tale! I've decided my $350 10" Heavy was a bargain after seeing what
that guy went through! Alternatively, is there an exploded parts
diagram available on-line anywhere? Attached is the relevant parts
list page from the Army Manual. Anthony (8383) |
| Evidently it is a 9" and 10K thing. The 10L uses a key that is
hooked over on each end to wrap around the ends of the worm. With
the apron assembled and the key in position, when you insert the
lead screw into the worm it locks the key into position. The key
can't shift axially because of the hook on each end and can't shift radially because the worm is on one side and the lead screw on the
other. I haven't yet scanned the parts list page so I can't attach
it to this message. Anthony (8384) |
| lurchix I don't
have a scanner. In any case, it applies only to the heavy 10, and
discusses how to install a conversion kit offered by the factory
after they changed to the lever clutch as part of the standard lathe
in 1958. The conversion kit was at least several hundred dollars
about 10 years ago (it included the complete clutch assembly,
including the pinion gear). If somebody needs a copy of the sheet I
can snail-mail it to them. Frank (8386) |
| You reckon the
ears-on-ends key idea is adaptable to the 9 and 10K? (8387) |
| SB 9A clutch
assembly |
| Does anyone
have knowledge or an available picture for the 9A clutch assembly on
the apron other than the exploded view parts drawing. I took my
apron apart to check it over and clean it. I have it all back
together except for the shoes, expanders and spring. There are a
number of ways these could fit together and I am ashamed to say that
I did not pay attention to how it came apart in the first place.
Actually, when I took the knob off the front, the clutch assembly
fell apart in the back before I could really eyeball it. Anyone have
knowledge of how these should fit together rather than trial and
error? Brian (9799) |
| Brian Check out the
pictures at http://steammachine.com/hercus/page5.html There are a
couple of shots of the clutch assembly. As the text that accompanies
the pictures says, "it's a job that needs 5 hands".
John (9802) |
| My lathe clutches
had a spring that went in last (I think) to hold the butterfly in
place. I didn't see one in the pictures. Maybe three hands and a
spring are enough to assemble it. Glen (9803) |
| Stick the clutch
guts in the wormgear, then lay a piece of cardboard against the
wormgear and turn the whole assembly face-down on the bench and it's
relatively painless to assemble. Don't ask how many times I had to
do it before I figured this out. Lurch (9805) |
| Halfnut slack |
| This reminds me. How much slack is ok in
the halfnuts? On my 9" model C, with everything off I engage the
halfnuts and I can use the handwheel to rock the carriage back and
forth perhaps as much as 1/16" or 1/8". Does this mean I need new
halfnuts or is it normal? Mark (10000) |
| Slop in the half
nut is no big deal you only start and finish the threads in one
direction anyway. our big machine at work has a good amount of slop
in the lead screw so you need to make sure you back the tool
completely out of the threads before you reverse. Kerry (10002) |
| 9" apron
question |
| Does anyone know
what the end play there should be on the worm gear on a 9 inch model
A/B apron? (10961) |
| I just got through rebuilding mine,
and reported that I got it to 0.003". Then Rose posted that IS the
factory spec from South Bend! (10963) |
| I think you've
answered the wrong question. I think your answer applies to backlash
in the cross feed screw, Steve was asking about the end play in the
worm surrounding the leadscrew which converts leadscrew rotation to
drive the automatic longitudinal and cross feeds. Anthony
(10984) |
| Repair
halfnuts |
| Has any one heard
of repairing the half nuts by pouring babbit in the? Roy
(12074) |
| There was such an
article in either Home Shop Machinist or Machinist Workshop within
the past year or two. www.villagepress.com The author removed the
worn thread, built up the area using a torch and brazing rod, then
cut new threads. Ken (12076) |
| I finally got
around to it. I fixed the halfnuts on my lathe. It's pretty cool and
came out pretty well I think. (this got a little long, but I'm a
little excited) Built up an angle plate jig out of 4" angle iron.
Mounted my half nuts with the proper spacing and then bored them out
on the lathe. Chucked up a piece of brass (that was even in the
drawer when I got it) and turned it down to a few thousands less
than the bored out halfnut. Coated it all good with some JB Weld and
let it sit over night. I was going to tap it on my mill but did not
have nearly enough travel to run a full tandem tap though the
bushing. Set it up on the lathe and used the tailstock to get it
started straight and then just ended up hand tapping it. The
splitting of the halfnuts was probably the crudest part of the whole
procedure and that was mostly due to my impatience (excitement) at
that point. I split them using a hacksaw. It came out ok, I would
have preferred to use a slitting saw or something similar to get a
nice clean, parallel cut. Drilled out the little oiler hole and then
put everything back together. First time I tried to engage the
halfnuts everything jammed up. Couldn't figure out what was going
on. Pulled the apron back off again. Moved all of the levers and
what not, and did not see anything wrong so put it back on (again).
Everything worked fine this time. First 1/2 dozen engagements or so
were a little stiff, but it is very smooth now. After all that, had
to find something to thread. Look around a little bit, hey here's a
bit of 3/8 rod. Perfect 3/8 - 16. Don't need to pay attention to the
thread dial or anything. Just click it in anywhere and it will work
out. Having fun now! Jeridiah (13034) |
|
Non-functioning clutch on 10k |
| The clutch just
blew on my recently purchased 10k. Any observations, advice, or
instruction?
(14616) |
| I believe you are
talking about the clutch on the apron. First thing to do is to
dismantle the apron and see if there is any broken parts. You would
be surprised to see what can gather in this area on the apron
(specially that it is anew lathe for you and you don't necessarily
have the full history of the machine). When I bought my 10K that I
am currently rebuilding, it was filled with a mix of wood dust and
metal filings (and a bit of oil) First remove the lead screw, then
the two screws that hold on the saddle that hold the apron. There is
a sheet metal cover that protects the clutch, with 4 screws. remove
the screws. Be careful when removing the cover, there is a small
paper gasket. You don't want to damage it. At this point, you will
see the clutch mechanism. To get the clutch apart, you will need to
remove the clutch knob. there is a screw in the middle of the clutch
knob. Be careful, this a left hand screw! After you remove this
screw, everything should come apart. Observe carefully how the
clutch parts are assembled. There is a small spring that holds in
place 2 half discs. To remove the worm, you will need to remove the
split nuts. Then, there is a small pin that has to be removed from
the collar (right side when you have it on the table). The key
should come out at the same time. Then, turn the worm and it should
slide out after a few trial and errors (do not apply any force,
there is a position it slides free, the way the worm is cut) Good
luck. Do you have the part manual? The explosion view is not very
good but useful. If you don't I could send to you a scanned copy of
the 2 pages (including the part list) Guy (14625) |
| Half nut
repair |
| I made a jig to hold my Half Nuts
for my SB9 just as they would be clamped up on the machine. I am now
ready to do what ever repair I need to to get them back going. I
looked at boring them out and putting in a Bronze bushing but it
looks like the casting will be too thin if I do that. I am thinking
brazing will be the way to go. Does anyone have a clue as to what
brazing material I should use or should I weld them up. I plan on
boring the hole to size on a horizontal boring mill here at work
then threadmilling the acme thread in there so I guess the rod
material could be pretty hard and wouldn't hurt anything. Any other
suggestions on how to do this repair? I am tempted to just make the
hole thing out of stainless billet. No one can see them anyway.
(15178) |
| In the files
section, see the folder "RestoredHalfNuts". In this repair an epoxy
is used. I believe this guy offers this service, as I think I've
seen these on eBay. Jeff (15181) |
| There was an
article in HSM about renewing halfnuts. I made the bracket and bored
out the worn threads and filled in the old halfnuts with brazing
rod. I used furnace patching material to build a dam to keep the
molten brass from running all over the place. The guy Jeff is
talking about seems to have a better system. If I was going to do it
again, I would try the bronze sleeve and epoxy route. Glen
(15188) |
| I have rebuilt
about eight or nine sets of half nuts for 9"/10K South Bend lathes.
These have been sold through eBay for $100.00 per set which beats
the LeBlond price by about $140.00. I seemed to have saturated the
market at this point and business slowed down, so I haven't been
listing them for a while. I get the old nuts back in exchange. I
have two sets ready to go right now in case you are interested.
Their is plenty of room on the castings to bush the nuts. These
dimensions are from memory now since I am sitting at my work
computer and my notes are at home: my jig is designed to hold the
nuts in the same orientation they are in when they are in the closed
position on the leadscrew. I use a special tool to get the nuts
properly centered, and then bore them out to what I remember to be
0.090". I then make a new flanged bushing out of bronze that has an
outside diameter of 0.860", and an inside diameter of about 1/2".
The nuts are then taken off the jig, opened and the bushing is glued
in using ordinary JB Weld epoxy. The nuts are then placed back in
the jig in the proper orientation for the epoxy to set. Next I bore
the inside of the bushing to the correct minor diameter for the acme
thread. I don't remember what this dimension is at the moment but
have it in my notes at home. The nuts are then threaded with an acme
threading tool in a boring bar on the tool post. You have to go slow
with this threading tool and take small cuts only, since this is
actually a form tool and as such, it is being advanced straight into
the work. I use an old leadscrew as a gage to determine when the
thread is finished. This process is better than brazing and does
away with all the distortion and gaps where the bronze doesn't want
to go (or where gravity is working against you). Since the bushing
is flanged, it is sound in terms of taking up lateral load. Once the
thread is complete, you slice the nuts and clean up the surfaces on
the mill. I also sand blast the nuts to make them look really nice.
I have had no complaints and only compliments. None of the nuts have
come back, so they must be working fine. They work fine on on my 9"
South Bend. Perk (15196) |
| 9" half nuts
|
| Exactly what should
I look for to evaluate the condition of a set of 1/2 nuts? I suppose
they should have flat surfaces and sharp corners, but is there
something specific? Jerry (15435) |
| I have
rebuilt a fair number of these half nuts and have seen a lot of worn
nuts in the process. New half nuts will look like perfect acme
threads. The lands on the threads will be the same width as the
bottom of the grooves. As they wear, the lands will become thinner
and thinner while the grooves will become wider. Looking at the side
of the thread that takes up the load, you will over time begin to
see a wear line from the leadscrew just above the bottom of the
thread. You can use them until they fail, and strip out without
sacrificing accuracy in thread cutting. In threading, you always
take up the slack in the same direction for each pass, so the slop
doesn't affect the operation. Perk
(15436) |
| Half Nuts and
saddle questions |
| Upon
further inspection of my lathe, I noticed the Half nuts are warned
down for the leadscrew. Also, I could pick the whole saddle up off
the ways. The tab that holds it on the side opposite of the apron is
there, however I do not see such a thing for the side of the apron.
IS gravity trusted to do this job? Also, what should I do about the
half nuts? Buy used ones in slightly better condition? OR is there a
source for new ones that are not very expensive?
(15610) |
| There is a note in
the "files" section on half nut repair. also see 15196 on a source
or repaired half nuts. Jim B. (15613) |
| Thank you, I have
read that, and I would do that modification if I had a decent lathe
that was operable. I would have to use my Chinese mini lathe to do
that boring/threading/turning operation. I'm not sure it would be
worth doing on that boat anchor. I'm going to look for some used half
nuts in good condition, will check my local classifieds. If anyone on
the list would like to sell me an extra pair they have, contact me
offline. (15615) |
| Message 15196
details the process for repairing half nuts. I have posted some
pictures of the finished half nuts in the SouthBendLathePics group
under "Half Nuts". I currently have a couple of these ready to go
for the price of $99.00 plus your old nuts in exchange. Perk (15616) |
| Just the nuts, or
the mounting studs and nuts as well? I was wondering how to contact
you because your email is not present. I will have to think about
it, If I cant find any used ones locally, I'll let you know. (15617) |
| You can find the
used half nuts on ebay , also there is a seller that sells rebuilt
half nuts on ebay if you are talking about you being able to lift up
the saddle/apron side that is closest to you, this is normal, the
backforce from running keeps this against the ways, there is a
saddle lock down clamp available to keep the saddle from moving
horizontally when facing etc. Clint(15623) |
| The nuts you see in
the pics file is what you get. I ship them within 24 hours of
receiving your old nuts and $99.00 plus $7.00 for shipping (total of
$106.00). Or, you can get new nuts from LeBlond for $244.00 plus
shipping. Maybe I didn't read your post carefully but I have never
heard of someone replacing the studs and nuts also. These do not
wear out. I suppose if you had to, you could make them. I'll bet
LeBlond would also sell them to you for a tidy price though! Perk (15630) |
| SB 9A Apron
questions |
| I found a few
problems inside the apron. The spring (part #16) is missing from the
clutch shaft. Does anyone know the dimensions of the spring? Is it
available? Another spring (20A) on the end of the same shaft was
also not there. This one seems like a locking thingy. Same
questions. What is the thickness of the sump gasket? Is thickness
critical? The sump was packed with a mixture of swarf and either
heavy oil or grease. Very dry, glad I got in there. I could also use
a little coaching on the clutch (shoes, expanders, etc) reassembly.
I'd like to get it right.
(16961) |
| Rose Marvin
at South Bend Lathe should be able to help with parts.
http://www.southbendlathecorp.com/index.htm
The sump gasket on mine was paper thin. I don't think the dimension
is critical. Tightening the clutch knob pulls the shoes in from the
center and forces them out to contact the inner surface of the
"well" that they sit in. The (20A) spring thingy kinda keeps the
shoes lined up with the center shaft. Glen (17022) |
| Question on
heavy 10 Carriage |
| I got a heavy 10
South Bend lathe with 3-1/2 foot bed. On the carriage on the back
part there are two spring loaded steel balls that are on top of it
on each side. What are these for? Also on mine it is missing the
back part of the cover for the cross slide. The cross slide threaded
screw is exposed in that area and I need the piece that goes there
to cover it up so chips don't get down in there. I don't have the
taper attachment although it looks like one could be installed on
it. I can't afford the taper attachment right now but would like to
get the cover for the back part. Gary (17412) |
| Gary, Why not make
one out of sheet metal for the time being? I have "Rube Goldberg" or
shall we say "creative attachments/lights" all over my machines.
Larry (17413) |
| The spring-loaded
steel balls you describe sound like oilers. (17414) |
| Gary, They are
on page #2005 of the Mc Master Carr catalog. Just press on the little
ball and it will allow a few drops of oil to get in then reseal
after you stop pressing. I too was stumped by them first time I saw
mine. Now I feel like I'm not the only one that didn't know that BTW
one of mine isn't working right and I need to order one. The ball
won't depress. Is there a way to clear them easily, folks?
http://www.mcmaster.com/
Tom (17417) |
| Tom I thought
that they might be for oil. Just wasn't sure. I just got back in
from the garage. I went through everything on it taking it apart and
oiling everything back up with proper machine oil. I understand how
everything works and where all the oil goes now. It really is simple
once you see it apart. On your sticky ball problem maybe you could
spray some WD40 or penetrating oil on it and take a brass punch or
similar soft item and lightly tap on it to loosen it up. It is
probably full of crude. You might have to take the carriage off and
clean it out from the under side. It is really easy to do. Just take
the 3 bolts on the back bottom side loose and remove the clamp bar
thingy. Then take the two large screws loose up front on top and
lift the carriage off. Gary (17418) |
| Gary. I wanted to try taking off my carriage but those two
screws on the front top section of my carriage won't let go. I'm
afraid to really force them and bugger up the slots. Might try
penetrating oil or something. I never thought of wd40 to release the
ball in the oiler. I'll give it a whirl. I'm like you ,I don't seem to
really get a handle on how it works unless I can take it apart. Tom (17419) |
| Tom, To clean the
oilers you can try brake cleaner in an aerosol can sprayed in from
underneath and you may have to pick out some of the crap with a
needle or small pick while you do it. If you can't take the front
screws out you can always slide the saddle off of the end of the
bed. Remove the leadscrew end bushing and put a wood block under the
lead screw for support while you remove the saddle. You will be able
to better see inside of the apron from behind and clean that out at
the same time as you clean the oilers. JP (17422) |
| Hey great Idea
JP. I'll try that sliding off the end idea as soon as I feel well
enough to do it, Thanks. I always wanted to get inside that apron
anyway. Tom (17425) |
| Gary, My
heavy 10 did not have the back cover for the cross slide, so I made
one out of sheet aluminum and it has been doing a good job. Russ
(17436) |
| Apron worm
gear replacement |
| I am in the process
of re-construction of a South Bend 10K lathe, a big challenge.
Recently I decided to manufacture a new apron worm gear. My previous
gear was in a poor condition.... years of abuse by previous owners.
There was the ebay solution..... not a challenge. At first, it looks
like something almost impossible to manufacture in a home shop. I
found a piece of cast iron round stock 2 1/8 in dia. and cut the gear
blank to the original dimensions. Everybody can do that with no
difficulty. The problem starts when comes time to cut the gear
teeth. As it is a worm gear, conventional method of gear cutting
cannot be applied. I made a small jig that holds the gear flat on
the compound rest at the proper height so the middle of the gear is
at center height.. For indexing, I used a 36T gear from my metric
gear transposing set. A small arbor drilled through held the
indexing gear on the gear blank with a press fit. I mounted a fly
cutter with acme screw profile in a a piece of 7/8 in dia round bar
mounted in the spindle. I set up the gear box to 6 TPI and reverse.
I cut the teeth like a screw, indexing the gear once in a while.
(taking many cuts for one set of teeth at a time. The cutter works
up to 5 teeth at the same time. I run the lathe at very low speed. I
stopped after each pass, moved the carriage back and increased the
depth of cut by 4 to 5 thou at a time. Every time I indexed, I
started the depth of cut to 0 again. With the exception of very
minor cosmetic glitches during the cutting process, (once getting
close to the final depth I realized too late that I was engaging the
split nuts with the gear blank too close from the fly cutter... the
carriage was not moving yet but the fly cutter was taking a light
cut on the top of the first gear tooth of the pass) I ended up with
a gear that runs very smoothly in the apron. This technique can be
used to cut any worm gear. It is time consuming. It took about 6
hours to cut gear teeth. Couple hours to manufacture a jig that can
be used only on one lathe because of the distance height between
the compound rest and the lathe center. (has to be within a few
thousandth of an inch) In my case, it was done on a Atlas 12 that had
the saddle re-ground after I discovered it warped. The compound rest
was also hand scraped to remove manufacturing defects. My jig
thickness was 0.893 in thick for a 1.190 in from the center to top
of compound rest. The fly cutter was running on a 1.42 in diameter
path. The worm is 1.375 in diameter but there is a need for bottom
clearance in the gear. From the original gear, I figured out a 0.022
in clearance required. I will try to post pictures on the web site
next week. Guy (18016) |
| Apron clutch
construction |
| I own a couple
lathes and am looking to add another. I have a couple Chinese
lathes, and I'm looking at a full sized SB 10 or 13 for larger
projects. I also would like to make a modification to my Import 920
lathe. Back in my shop class days I learned on a SB Heavy 10. I
purchased a grizzly G4000 a couple years ago and have been happy
with it. I looked at SB's but the beds were shot, the machines were
abused or the price for one in good shape was not worth it for a
small 9" lathe. Anyways, I would like to modify my G4000 to have an
apron clutch like the SB. The lathe already has a power feed, but it
is geared the whole way, meaning that if a micrometer stop were
placed on the ways, the stop would move or some part would break. I
would like to replace the geared feed engage lever with a clutch
design based on the one found on the deluxe SB aprons. I have found
exploded diagrams of the apron, but the are very hard to follow and
very confusing. Has anybody taken their apron clutches apart? What
does the Knob/ Lever (depending on year) pull up on to engage the
feed? G.
(18228) |
| On my 13" SB Apron
Clutch Handle pulls UP to engage. Ron (18238) |
| The clutch is a
multi-plate clutch, with alternating plates connected to inside and
outside splines. The outside sleeve (which contains splines on its
inside for one set of the clutch plates) has an integral pinion gear
which rides on the worm gear which in turn rides on the feed shaft.
The (hollow) shaft inside the clutch plates (which has outside
spines to pick up the other set of alternating clutch plates) drives
the selected feed (when the clutch is engaged). A pull rod which
runs down the middle squeezes the alternating clutch plates
together, engaging the clutch. On the knob clutch, a simple screw
(tightened by a knob) pulls on this pull rod. In the lever clutch, a
cam arrangement pulls on the pull rod when the clutch lever is
lifted. Does that help? Frank (18251) |
| Half Nut
Repair |
| Doesn't one of you
guys out there in radio land repair half nuts? This "new" 9 inch SB
I just got has some pretty bad half nuts. I'd be interested in
swapping for a rebuilt set. (18444) |
| Craig, Do an
archive search as there are members here who do the half-nut
rebuilds. Also check the files section for info on how to repair
them yourself. BK (18445) |
| There is some files
in the drop box for the rec.crafts.metalworking group. This is the
author. contact him about what you want. Brett Flemming
efficientvelo@a... Jack (18453) |
| Check out post
17906. He goes by "Perk in Cincinnatti" and I believe he has
repaired half nuts on the shelf ready to ship, not just through
ebay. I searched the archives for "perk" and found him.
Mike (18455) |
| Craig; I am
the one who does the rebuilds on South Bend half nuts for the 9" and
10K. If I can ever find an extra pair of worn out nuts for a Heavy
10, I will begin doing those too. I have a pair currently listed on
ebay as item number 3809481581. You can get the complete story on
the ebay listing. If you want, you can also email me off the list to
conduct a transaction through this list, or to get more information.
Perk (18458) |
| Clasp nuts /
Split nut SB 9" |
| I have a South bend
9" model A that has a very worn out set of Split nuts ( Clasp nuts )
. Does any one know where I can get a set of these at reasonable
cost. (18834) |
| There is somebody
on the discussion group that rebuilds them. You trade your old split
nuts with $$$, against refurbished nuts with brass/bronze inserts.
If you go on the photos, his work is displayed there. Guy (18836) |
| DW Carter; Depends
on what you call a reasonable cost! I am the one who rebuilds half
nuts for South Bend 9" lathes. For more information, see messages
18458 and 15196. If you want to see the finished product, go the the
picture repository at SouthBendLathePics and check under the file
labeled half nuts. The price is $109.00 with exchange of your old
half nuts. This includes shipping anywhere in the US. I
occasionally list them on ebay also. If you want, you can get them
from LeBlond for $244.00. If you have an interest, email me off the
list and I can tell you where to send your old half nuts. Perk (18860) |
| Worn worm
wheel SB 9" |
| I have a Southbend
9" with a very worn worm wheel. This is the worm wheel that encases
the feed clutch !. Has any one got a source of reconditioned / used
or new units. (18856) |
| DW; It's me again!
(perk in Cincinnati). I just happen to have a complete clutch
assembly with a like new worm gear. How I came about this is another
story, but what is important to you is that I have it. I will sell
it to you for $79.00. Before choking, check out the price of this
assembly from LeBlond. If you are interested email me off list. Perk
(18861) |
| If you have some
time to spend, can still use your lathe without the gear in place,
have basic threading skills, you can cut a new gear on your lathe. I
have done it , using a atlas 12 lathe, using a 36T gear as indexer,
and lot of time on the machine. If interested, I can send you
pictures of my setup as well as pictures of the result. You need to
send me a email home as I pick up all traffic from the web site. It
is a nice project for a home machinist. What is required: a 7/8 in
round stock steel bar some blocks of steel a couple screws a piece
of cast iron 2 id dia X 2 in long (extra required to hold the blank
in the chuck) a broken center drill 1/4 in dia a lathe that can be
set up to cut 6TPI LH a small milling machine or shaper many
enjoyable hours in the shop. Guy
(18866) |
| Fitting new
half nuts |
| I just installed some replacement half nuts onto my SB9C.
After I reinstalled the carriage I engaged the nuts (without
running) and noticed that they were causing the lead screw to
deflect downward a slight amount. I didn't measure it, but would
guess it deflected the screw by say 0.075 inches. I'd have to think
that this extra pressure between the lead screw and the half nuts
will cause unnecessary wear. I was thinking about shimming the lead
screw bearing at the tailstock end to try and eliminate the bending.
Anyone ever run into this and am I on the right track?
(21676) |
| IMHO you
will cause yourself more problems by taking this approach. If the
leadscrew was ok prior to the halfnut change, then obviously there
is nothing wrong with the leadscrew WHY "fix" it. The problem is
with the halfnuts, so you REALLY need to fix the "halfnut problem"
-- Peter
(21701) |
| Presumably this
implies that the top half nut is getting there first. I'd be more
inclined to try shimming the bottom half nut (if that's possible) so
that the two halves meet the screw at the same time.
(21702) |
| The half nuts are
on pivots. No way I can think of the "shim" those. (21706) |
| One way to move the
pivot point is to re-drill the hole oversize, on the desired center
and bush it, or you could use an eccentric bushing and make it
adjustable. Mario (21708) |
| I guess I'm missing
your point. This sounds like a massive PITA when compared to
shimming the lead screw brackets to make it ride a few thou lower.
The half nuts are designed to fit in the carriage and track a
theoretical centerline. On my machine it appears that the
theoretical centerline and the lead screw axis are displaced. If the
half nuts were pulling the lead screw up then I could shim the
carriage down a bit. since the half nuts are pushing hte lead screw
down it seems that lowering the lead screw would be the way to do
it. (21710) |
| Graig, you wrote
that there was .075 of movement. That's 7 and a half thou. I wouldn't
worry about it. The nuts will where in anyhow. the only time you use
them is cutting threads and the lead screw runs slow. Duane
(21712) |
| When I went to
school, and that was a long time ago, 0.075" was seventy five
thousands of and inch. about 5/64" Jim B(21713) |
| I can visibly see
the movement. It is not quite a tenth of an inch so I guessed 0.075.
Yes I agree that is 75/1000 of an inch.(21714) |
| You're absolutely
right, Peter. 75 thousands is a pretty fair amount and with a 9C
where your half-nuts are used for turning as well as threading,
you'll see accelerated wear. I'm wondering if you bought new or used
OEM half-nuts or did you have them bored and bronze inserts
installed? If the latter, you might check to see if it looks like
the bored out iron body got bored off- center when the old threads
were removed to make room for the insert. If that's the case, you
might be able to remove the bronze inserts, build up both halves of
the iron body with iron-filled epoxy, rebore and reset the inserts.
Maybe clean off the oil, blue the nuts and see where they're making
contact on the lead screw as a clue? Might be they're tilted enough
to make contact at one side or the other first and thereby deflect
the lead screw. I'm assuming that the situation exists along the
entire length of the bed so that the nuts won't close at all near
the tailstock-end bearing support where the lead screw cannot
deflect under the pressure? If you ultimately decide to shim, don't
forget about also shimming the lead screw bearing at the headstock
end. Ed (21715) |
| Sorry Peter, Sorry
Craig for getting you mixed up in my below message. Ed (21716) |
| It sounds a lot of
misalignment to me. Is your apron properly screwed to the saddle?
Such deflection could also be caused by the wear on the bed/saddle
but never to this extent. Guy (21717) |
| Jumping in here. You said in your
first message that you'd shim the tailstock end of the lead screw. I
don't see how that would work. If the half nuts are pushing down
on the lead screw, then they're still going to push down at the
headstock end when the saddle is at that end. It would fix the
tailstock end, but then the leadscrew would be at an angle to the
bed. Are you sure there isn't something else wrong? Maybe the apron
or even the whole saddle has been displaced down, pushing the
half-nuts into the screw? How's the alignment of the saddle rack?
(21720) |
| OK, but you will
need to shim both ends rather than just the tailstock end, otherwise
the deflection will simply vary in amount along the length of the
bed. (21721) |
| It seems to me that it
wouldn't be much trouble to remove the appropriate amount of metal
from the pin of the upper half nut. Therefore reducing the downward
travel. I wouldn't think that would weaken it too much. Marshall
(21722) |
| Are the new nuts a
matched pair, with the same numbers on both halves? If there was a
mix up that might do it too. The nuts are bored threaded then split
apart later. Jim (21734) |
| My first impression
on reading this was that there must be a piece of swarf or something
between the saddle and the apron. Is the apron and saddle original
to the bed? I have repaired a set of half nuts per the article in
HSM a while ago and I had no problem with alignment. Where did the
new half nuts come from? Glen (21738) |
| Yeah I'd probably
have to shim both ends. The lead screw should be parallel to the
carriage line of travel. I really didn't get a lot of time to
examine the issue along the whole length of the ways. I'm in one of
those modes at work and home where "free" time for my own ends is
rather limited. I was really doing good to just get the new half
nuts installed. (21742) |
| These are old stock
used half nuts from a parter-outer. They still have a good amount of
life left. But as you well know the half nut cast iron is soft stuff
when compared to the steel lead screw. Unnecessary pressure or side
load is just going to wear away nut surface much faster. Definitely
though I'll end up having to check the "fit" along the whole bed.
One problem though is the lead screw gets stiffer the closer you get
to either end of the bed (due to the proximity of the supports). So
at either end it may be real tough to see the deflection.
(21743) |
| Didn't check that.
Wouldn't have thought of that possibility. Picked them up on Ebay
from Jeff Burris. (21747) |
| Yeah some crud between the saddle and apron
could push it in the direction I'm seeing. I thought I had it
cleaned but it is easy enough to take apart and try again. The
saddle and apron are matched and original to the bed. The half nuts
are Ebay. I wanted to go fix my old ones with bushings like you did,
but finally had to admit to myself that I'd never get around to it.
(21748) |
| Slop in apron
handwheel |
| I have an old Southbend lathe and the serial # is 34124k
Cat.# CL0670Z. The apron handwheel has a lot of play. Not so much
play in the actual feed, but as if the apron handwheel shaft is worn
out. Are there bushings in the apron? If not does anyone know how
this can be fixed? Also is it just the tapered pin that holds the
wheel onto the shaft? I called the factory before they went out of
business, and they told me that it was made Oct. of 1976. But for
now I am just concerned about fixing the slop in the handwheel.
(24350) |
| Mine has a little
slop also, doesn't hurt a thing but it bugs me. There is no bushing
when new. I thought about reaming the apron casting a little bigger
and a rounder hole maybe use a shell reamer, than bush my shaft to
fit. I think its just a taper pin that holds it all together. (24355) |
| My '49 9" also was pretty sloppy- I drifted out the taper
pin in the handwheel and pulled the shaft. Very little wear at the
pinion end, but a lot out near the handwheel. I cleaned up and
polished the shaft, then worked a piece of copper shim about 1" deep
into the lower side of the gap between the shaft and casting from
the front, wrapped around about 60% of the circumference of the
hole, then trimmed off the exposed shim and re-installed the wheel.
I made the end of the shim that goes into the hole first narrower to
ease insertion. Works good so far. There may be a better material
than copper for this, but that's what I had at hand. Still some slop
but a huge improvement. I'll be paying close attention to the oil
hole in the future. Mark (24370) |
| Mark, I don't think
the oil hole is much to blame. It is a poor design. Any time you
have a big wheel with a little shaft and one bearing point there
will be trouble some day. The biggest thing is fixing it or reducing
the slop as you did. Bob
(24375) |
| My nearly 70-yr-old
9" had a lot of slop in the wheel, too; I shimmed it and tightened
it up some but the shim didn't last; finally I bored out the hole
and turned a cast iron bushing and pressed in; probably last as long
as I'll care about. Rick A.
(24395) |
| Worm and wheel
drive for 9" |
| Does any one know
where I can get a reconditioned worm and wheel drive for the model A
9" Southbend, any advice will be greatly received. (25124) |
| I assume you are
talking about the worm and worm gear located in the apron. For your
info, the worm gear is easy to manufacture if you know how to
thread. I manufactured one on my Atlas lathe last winter. All you
need is a piece of 2 1/8" dia piece of cast iron, a 36T gear (for
indexing), a few blocks of steel to make a jig and a few hours to
spend on your lathe. It is not rocket science. Guy (25140) |
