# 12" Atlas Reverse Tumbler Gear Stud



## paul s (Aug 6, 2019)

Just got a 12" Craftsman/Atlas, going through it and making it usable.

Regarding the two smaller single gears - were the nuts on the back side staked?  I took the assembly apart for cleaning, and there doesn't seem to be any provision for keeping the nut from tightening all the way against the casting.  There's a shoulder on the stud where it meets the front of the tumbler casting, but not on the back.

Also, why does the headstock pulley have indexing holes, just like the bull gear?

Paul


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## wa5cab (Aug 7, 2019)

To answer your second question first, in any given year up until the end of WW-II (roughly the Summer of 1945), Atlas built three models of 12" lathes, 101.0736x, 101.0738x and 101.0740x. where "x" = 0, 1, 2 or 3.  The first group of four models had no back gears, so the right face of the step pulley had the indexing holes.  The first two groups had babbit bearings and the third had Timken bearings.  There is probably no way to prove what happened, but either the factory installed the wrong pulley (either by mistake or because they had a lot of them in stock after production of the babbit bearing lathes ceased) or a PO somehow damaged the pulley and maybe the factory was selling off the pulleys with the holes cheaper to get rid of them.

On your first question, no.  The two nuts are torqued against the back side of the Tumbler which locks the L3-48A Shoulder Bolt against the tumbler and prevents it spinning with the gear and double keyed bushing.  The two gears are standard A-suffix  Change Gears with 20T and 24T.  Although the parts drawings have never shown it, the A-suffix gears still have the same 3/8" face as the original no-suffix gears supplied on the x=0 and x=1 models but they have a 1/2" long hub, which sticks out from each face or side of the gears, 1/16" to each side.  Note that all of the parts shown for the tumbler and change gears with an "A" suffix have the 1/2" hubs or are 1/8" longer than the original parts.  These are used on all machines with x=2 and x=3, which includes your 101.07403.

Not that it matters to you, but the change gears and 1" long bushings were all carried over to the late 12".  For some reason, they changed the two tumbler gears on the late 12" instead of using change gears there.


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## paul s (Aug 8, 2019)

Regarding the pulley; anything's possible on this machine - I pulled it out of an estate and the history is unknown. The bull gear was rubbing up against the index pin and I couldn't turn the spindle, until I loosened the set screw and moved the gear inboard.  So, I suspect it's not completely original.

Regarding the tumbler gears; you're saying the shoulder bolt is stationary, while the gear and keyed bushing rotate?  That's what I would expect, but that doesn't seem to be the case here.  The gear will not rotate with respect to the shoulder bolt, in fact, it appears to be a press fit.  I put it on the arbor press and pressed the shoulder bolt out roughly 1/16" and there's still no relative motion.  I notice that my tumbler casting is L3-21A, while the parts list shows what appears to be L6-21.

Meanwhile, I've almost got the spindle out, but I'm fighting the woodruff key on the bull gear.


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## wa5cab (Aug 8, 2019)

Remove the gears, bushings and shoulder bolts from the tumbler.  Press the shoulder bolts out of the bushings and clean up the bolts and the bore of the bushings until the bushings will spin freely on the bolts.  Then reinstall and tighten the bolts and then install and tighten the nuts.  And confirm that the gears still spin freely on the bolts.  Apply a few drops of SAE 20 oil to each bushing and bolt.

As to the question of L3-21A or L6-21, I will try to remember to call Clausing and see whether anyone knows what the story is.  All of the 12" flat parts lists that we have show L3-21A, the "A" appearing with the appearance of the "A" suffix gears.  The later Illustrated or exploded view parts lists show L6-21. The one model where we have both types of parts list shows L3-21A on the early one and L6-21 on the later one.  And to further confuse the issue, back in 2012, I started downloading all of the parts lists off of SearsPartsDirect.  And all of those lists still show L3-21A,


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## paul s (Aug 8, 2019)

Thank you, Robert.

One of the gears/bushings had some old lubricant that hardened - I used isopropyl and 4/0 steel wool.  The other, however, had more issues.  The bore was distorted slightly near one face of the gear, which was remedied by forcing the bolt through and turning with a wrench, repeatedly.  The distortion was enough to keep the gear from freely turning.  Even worse, the shoulder of the bolt did not protrude through the gear.  I fixtured the gear with an expanding arbor on my South Bend and took a few cuts off the face.  I was surprised at how far off square the faces were to the bore.  And I don't think it's a consequence of the bore being distorted, I think it's still on-axis.  I put the tumbler back together, and there's no binding between the two gears, everything turns freely.

Any advice on that woodruff key on the backgear?  I tried prying up the outboard end with a screwdriver, tried needlenose pliers, wouldn't budge.  I thought maybe I could rock it back and forth, so I hit with a pin punch on the inboard end, no go.  When I hit it with the pin punch on the outboard end, it rocked a bit - of course, that doesn't help much, maybe even worse off now.


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## wa5cab (Aug 9, 2019)

I assume you are trying to pull the spindle.  Although this works best if you are using a drawbar and receiver (which keeps the spindle centered), try moving the bull gear and everything else on the spindle to the rear.  Then extract the spindle until most of the key is visible.  Dribble a little penetrating oil down both sides of the key.  Wait a few minutes and then use a pin punch on top of the rear end of the key.


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## wa5cab (Aug 9, 2019)

Back on the original subject, if one of the shoulder bolts is too short, it is probably the original "non-A" version.

The gear with the damaged bore sounds like a hammer blow damage.


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## paul s (Aug 9, 2019)

wa5cab said:


> I assume you are trying to pull the spindle.  Although this works best if you are using a drawbar and receiver (which keeps the spindle centered), try moving the bull gear and everything else on the spindle to the rear.  Then extract the spindle until most of the key is visible.  Dribble a little penetrating oil down both sides of the key.  Wait a few minutes and then use a pin punch on top of the rear end of the key.


Yes, I need to replace the two spindle gears that interface with the backgear, apparently, the zinc "pests" got to them. I don't think I can expose any more of the key at this point - it's all the way up against the inner bearing cover and the gears/pulley/collar are all the way up against the other inner bearing cover. I've tried penetrant and I'll try the pin punch again.


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## paul s (Aug 9, 2019)

Regarding the short shoulder bolt - do I have mixed parts from different versions?  The SN on the bed is 30478.


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## wa5cab (Aug 10, 2019)

If the short shoulder bolt looks like the long one except for length, that would be my guess.  Most commercially available shoulder bolts are socket head.  So if the too short one is hex head, it's probably an Atlas part.  But the gear hub length change dates from about 1938 and your lathe from early 1951.  So it is unlikely that the mistake happened at the factory.


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## paul s (Aug 10, 2019)

The too short one is hex head and is identical to the other one, but about 0.003" too short.  I'm guessing that the gear got changed at some point.


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## wa5cab (Aug 10, 2019)

OK.  Then your problem is not mixed version parts.  The Rev A part is 1/8" longer that the base or original parts.  Your problem is an out of tolerance part.  As it is unlikely that wear from use is the culprit, my guess is that it came from the vactory that way.  You have two choices - replace it (Clausing may still carry the part).  or shim it.  Check on some place like McMaster for bearing shims, inner race shims, outer race shims.  You might also try a place like Ace Hardware.  You would pay more for one shim, but you won't have to buy a box of them to get one.  The shim OD must NOT be any larger than the shoulder diameter.  It can be a few thou smaller.

Another possibility, if you have the necessary tooling, would be to reduce the thickness of the hex head.


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## paul s (Aug 11, 2019)

Actually, I solved the problem by skimming down the face of the gear on my other lathe.


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## wa5cab (Aug 11, 2019)

Well, that's also a viable solution.  But now you have two non-standard parts on the machine.


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## paul s (Aug 11, 2019)

As long as it makes chips - and the lathe is going to be a gift for someone who doesn't have a lathe, so I think they'll be able to look past it.


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## paul s (Aug 13, 2019)

Finally got that woodruff key out.  I ended up drilling and tapping for a 6-32 screw near the outboard end, and used a slide hammer.

Spindle is out, inboard bearing is still in the headstock.  I'd like to take it out for a full cleaning/inspection - do I remove the inner or outer dust cover and do I pry it with a screwdriver, or use a pin punch?  Also, is it common practice to replace the "filter" material in the Gits oilers?


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## wa5cab (Aug 14, 2019)

Glad to hear that you got the key out.  I think that this is the first time I've heard of drilling and tapping a hole in it and using a small slide hammer.

Yes, to remove the cup, you will need to first remove the inboard dust cover.  Then you can try the pin punch but the best choice is an aluminum disk just smaller than the hole that the dust cup fits into and either a slide hammer or better a length of 5/8" or  3/4" dia. threaded rod and a larger shoulder disk that fits the hole where the outboard dust cover fits.

Yes, replace the felts.  They also serve as filters.  Clausing still has them but you should preferably also have something else to order as they only ship UPS and UPS has a one pound minimum.


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## paul s (Aug 15, 2019)

Regarding the back gears and mating spindle gears on my 12" - would a babbitt head have the same gears as the timken head?


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## wa5cab (Aug 15, 2019)

Short answer is Yes.  Longer answer is that throughout the production of the 3/8" bed lathes (except for the 9" and the models of 10" and 12" that did not have any back gears), both the 10" and the 12" used the same components throughout the back gear assembly except that the 10" and 12" did not use the same left back gear bracket.  This is even partially true of the late 12" made from 1957 though March of 1981 in that the two back gears, sleeve (that ties them together) and bushings and two spindle gears are the same all the way back to about 1934.


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## paul s (Aug 15, 2019)

And so, the gears would carry the same PN?


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## wa5cab (Aug 16, 2019)

Yes.  The Atlas part numbering system identified whatever type or size of machine a part was originally used on.  At least up until the palace coup that changed the company name from Atlas back  to Clausing, for the most part Atlas did not assign a new part number to an old part simply because the part was used on a different machine than what it started life being designed for.  If you look at almost any parts list for any type machine, you will see examples of part numbers that do not match the machine that the part is being used on.  So if a part number is 10-242, it is still 10-242 even though the machine it's being used on is a 12".  If a table saw had needed a gear like that, the part number would still have been 10-242.  Or to put it the other way around, if the part number isn't 10-242, then a 10-242 won't work there.


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## RobertB (Aug 16, 2019)

paul s said:


> The too short one is hex head and is identical to the other one, but about 0.003" too short.


Was that as measured compared to the other bolt, or as compared to the gear?

Just speculating, but the bolt may have been fine and the gear could have been the problem. You mentioned other gears suffering from "Zamac disease" or "Zinc pests" and one of the first symptoms of this is parts beginning to swell. It's possible you gear may have begun to swell a bit.


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## paul s (Aug 16, 2019)

RobertB said:


> Was that as measured compared to the other bolt, or as compared to the gear?
> 
> Just speculating, but the bolt may have been fine and the gear could have been the problem. You mentioned other gears suffering from "Zamac disease" or "Zinc pests" and one of the first symptoms of this is parts beginning to swell. It's possible you gear may have begun to swell a bit.


Good point - that's estimating, just by looking at the gear/bolt combination assembled.  I never did measure the two bolts, just skimmed the face of the "fat" gear on my other lathe.

So, am I sitting on a time bomb, as far as these gears falling apart?  Or are they good for another 20 years?

Paul


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## wa5cab (Aug 16, 2019)

The Suffix A gear hub lengths were 0.500".  Probably +/- 0.005".  Same is true of the early and late bushing lengths.  Measure the hub length of the gear that you didn't modify and the one that you did.

As far as the Zinc Pest problem is concerned, it is generally thought that at this late date, if the parts haven't already failed, they aren't going to.


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## RobertB (Aug 16, 2019)

Well if it took 70 years for it to swell a few thousandths, I would expect many more years of service left in it.


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## paul s (Aug 17, 2019)

I measured the bushing lengths at about 0.574" - each was within 0.001" of the other.  I didn't measure the gears, mute point now.

I did order a backgear off of ebay, and made an offer on one of the spindle gears, as well.  The only one I can't locate is the bull gear.  I did call Clausing, just for the heck of it - they have a new bull gear, they quoted $202.95.  All I see on ebay are entire headstocks or entire spindles.  I may end up buying a whole spindle, taking the bull gear off it, and selling the rest.


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## wa5cab (Aug 18, 2019)

Yeah.  It is good that Clausing still offers some parts support for the Atlas machines.  But unless they overstocked on a part 50 or 60 years ago, it is going to cost what it costs in 2019 dollars and wage scales, not 1940's or 50's.  Just price a similar part for some newer US built machine (if there are any).


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## paul s (Aug 22, 2019)

I've now got a backgear assembly and a 10-242 gear for the spindle.

Regarding the 10-242 gear:  The teeth are noticeably smaller than the gear they mate with on the backgear.  I'm assuming this is caused by wear, although the gear is so clean, it may have been media blasted.  I'll attach some pics - is this going to cause problems?  I've also noticed that the bronze sleeve that fits into the bore of the 10-242 is loose, which I also noticed on my original gear; a consequence of the Zamac swelling?  It's essentially a slip fit - should I fixture it with some Loctite?

Just need to source the bull gear at this point.


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## wa5cab (Aug 23, 2019)

Paul,

It would appear from your photo that the small spindle gear has been bead blasted.  But I wouldn't worry about the slightly loose fit.  It won't hurt anything.

The bushings are sintered bronze AFAIK,  But the nature of the lubrication of the step pulley and small spindle gear bushings makes that less important than on some of the others.  I would wash and dry the outside of it and use Lockwick primer and Locktite Bearing and Bushing Mount and let it cure a day or two before re-installing the spindle.  I would be more inclined to blame the bead blasting for the loose bushing fit.  I've not heard that bad Zamak castings swell appreciably but if they did and if that were a problem here, the ID would grow smaller, not larger.


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## RobertB (Aug 23, 2019)

That almost looks like the new gear is 20 deg. pressure angle and old gear is 14-1/2 deg. Where did you get the gear?


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## paul s (Aug 23, 2019)

I bought the gear on ebay - the PN, "10-242", is cast into it.  Interestingly, the bushing on the original part is loose as well - very loose.  Like maybe 0.020 under.


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## RobertB (Aug 23, 2019)

The correct part, then must just be well worn. Should still function but may be a bit noisy and have some extra backlash.


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## wa5cab (Aug 23, 2019)

So both gears fit the new bushing loosely?  Where did you buy the new bushing from?  

What about the old bushing?  Is it also a push fit in both gears?


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## paul s (Aug 23, 2019)

Yes, very loosely.  The bushing came with the new gear off ebay - I'm assuming that's the original bushing that came with the gear.  There is evidence of the new bushing having been media blasted on its OD.

The old bushing is loose as well.  Both bushings measure about 1.750 to 1.751 OD, while the new gear measures 1.756 in it's bore.  The ID of the new bushing is around 1.504, while the old measures about 1.502.

The old gear measures about 1.797 it it's bore.


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## wa5cab (Aug 24, 2019)

I don't know how well it will work on sintered bronze but I would try knurling and then install it with Locktite.  You will need an expanding arbor.  There used to be a cheap Chinese set on eBay pretty regularly.  I think it went up to 1-1/2".


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## paul s (Aug 24, 2019)

Might be easier to drill and tap down in the root of one of the gear teeth for a small setscrew to retain the bushing.  If needed, I could wrap some 0.001" brass shim stock around the OD of the bushing to equalize the gap.


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## RobertB (Aug 24, 2019)

paul s said:


> If needed, I could wrap some 0.001" brass shim stock around the OD of the bushing to equalize the gap.


That would be the option I would choose, whatever thickness you can get a good fit with a full wrap to keep it centered. Loctite doesn't grip oilite very well unless you remove all the oil impregnated in it, but knurling like wa5cab suggested would probably be enough to let the loctite hold it

If you had a working lathe you could just make a new bushing


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## wa5cab (Aug 24, 2019)

paul s said:


> Might be easier to drill and tap down in the root of one of the gear teeth for a small setscrew to retain the bushing.



I wouldn't try that.  Considering the bushing as being rigid, the set screw will push the bushing off-center.  And worse, compared to the gear and the spindle, the bushing is flexible.  so after pushing it slightly off center, further tightening will distort the bushing where it is under the set screw.  At the very least, knurling does not have either of those disadvantages.


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## wa5cab (Aug 24, 2019)

paul s said:


> ...  There is evidence of the new bushing having been media blasted on its OD.  ...



Sintered bronze bushings often have a surface appearance similar to one that has had light media blasting, except not shiny.


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## paul s (Aug 24, 2019)

RobertB said:


> If you had a working lathe you could just make a new bushing


You mean like this?  But then I would have to order a chunk of bearing bronze ($$$).  McMaster-Carr has bronze bushings, but the OD is 1.750 -0.000, +0.001, not much help.


wa5cab said:


> I wouldn't try that.  Considering the bushing as being rigid, the set screw will push the bushing off-center.  And worse, compared to the gear and the spindle, the bushing is flexible.  so after pushing it slightly off center, further tightening will distort the bushing where it is under the set screw.  At the very least, knurling does not have either of those disadvantages.


Brass shim stock wrapped around the bushing will keep the bushing centered, and drilling the hole with the bushing installed, I could lightly drill a depression in the bushing so that the setscrew wouldn't have to be tightened down much.  A little blue loctite on the setscrew, and done.

Or just shim stock and loctite - is the bushing oilite?  If so, I suppose that rules out gluing it in.


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## RobertB (Aug 24, 2019)

Definitely no set screw, either knurl or shim stock to a tight fit. Not much turning force on the bushing so loctite may not be needed in either case.

or https://www.mcmaster.com/6391k673 turn down to fit.


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## wa5cab (Aug 24, 2019)

paul s said:


> Brass shim stock wrapped around the bushing will keep the bushing centered, and drilling the hole with the bushing installed, I could lightly drill a depression in the bushing so that the setscrew wouldn't have to be tightened down much.  A little blue loctite on the setscrew, and done.
> 
> Or just shim stock and loctite - is the bushing oilite?  If so, I suppose that rules out gluing it in.



Well, its your machine.  But I have never had any luck with shim stock that was too thin to itself stand up to being pressed into a bore.  What usually happens is that the shim stock will go just a little ways into the bore that you are pressing it into and then it stops going in with the bushing (or shaft or whatever) and just balls up around the outside of the hole.  Whereas lightly knurling the OD brings its OD up enough to be a tight fit in the bore without any shim.

As to whether or not the three bushings (one in the gear and two in the pulley) are Oilite or not I don't know for certain.  They don't really have to be as there is supposed to be a gap between the two bushings in the pulley into which oil from the oil hole can exit.  And from there, it can run fore and aft along the spindle.  The gap acts as a reservoir for a while.


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## paul s (Nov 8, 2019)

Finally getting back to this - I ended up using 0.001" brass shim stock in four places around the bore of the gear to keep things centered and take up some gap.  Held it all together with Permatex sleeve retaining compound.  It's not coming apart again, at least not without some intention.

Now I'm putting the headstock back together, and I would like the lathe to start it's new life with a fresh spindle belt. 
The original is marked "S7-126".  I measured it two ways:  by making a mark and rolling it - 31.5"; by a string around it's OD - 32".  An online search wasn't definitive - some sources say 32" (4L320), some say 31" (4L310).  Opinions?  Or is the tensioner range enough to cover either?


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## wa5cab (Nov 9, 2019)

As best I've been able to determine, it should be a 4L310.  S7-126 says that it was first used on the Shaper, which came out a little before the 101.07403.  The 101.07383 spindle belt is shown as L4-126.  My guess is that one of them is 31" and the other 32".  You could just buy one from Clausing to see.


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## RobertB (Nov 9, 2019)

An A29.5 or 4L315 would give you the 31.5" that you measured. These guys (never dealt with them) https://www.vbeltguys.com/products/s7126-atlas-press-oem-equivalent-conventional-v-belt say 32" and vintage machinery says 31" http://wiki.vintagemachinery.org/Atlas-V-Belt-P-N-to-Length-Cross-Reference.ashx


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## paul s (Nov 9, 2019)

wa5cab said:


> As best I've been able to determine, it should be a 4L310.  S7-126 says that it was first used on the Shaper, which came out a little before the 101.07403.  The 101.07383 spindle belt is shown as L4-126.  My guess is that one of them is 31" and the other 32".  You could just buy one from Clausing to see.


Yep - but I'd need to take out a 2nd mortgage


RobertB said:


> An A29.5 or 4L315 would give you the 31.5" that you measured. These guys (never dealt with them) https://www.vbeltguys.com/products/s7126-atlas-press-oem-equivalent-conventional-v-belt say 32" and vintage machinery says 31" http://wiki.vintagemachinery.org/Atlas-V-Belt-P-N-to-Length-Cross-Reference.ashx


Yep - lots of conflicting information out there.

I think I'll roll the dice and go with a 32" - thanks all!

In the meantime, I've been disassembling the tailstock and can't remove the quill because the quill lock is bound up.  I've got the lock handle and bolt removed, but the two lock sleeves are stuck and I can't get them out of the casting.  I'm guessing one needs to come out the top, the other out the bottom.  I may try to tap and thread the ID on the top one and use a slide hammer or just drill it out and make a new one.  Is this another case of the swelling Zamak?


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## RobertB (Nov 9, 2019)

paul s said:


> In the meantime, I've been disassembling the tailstock and can't remove the quill because the quill lock is bound up.  I've got the lock handle and bolt removed, but the two lock sleeves are stuck and I can't get them out of the casting.  I'm guessing one needs to come out the top, the other out the bottom.  I may try to tap and thread the ID on the top one and use a slide hammer or just drill it out and make a new one.  Is this another case of the swelling Zamak?



Could be swelling, but also corrosion or over aggressive tightening are possible. You can remove the crank, key, endcap and feed screw. Soak with penetrant and then with a brass punch gently tap the quill fore and aft and see if that will break them loose. Tapping the top one as you suggest could work. You could also remove the anti-rotation bolt and try and twist the quill. Heating the whole assemble a bit may also help. With the quill out both parts will come out of the top.


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## paul s (Nov 11, 2019)

Well, I've got the handwheel off, but the endcap is not moving.  I've tried wrapping thick leather around it and using pliers, and I've tried a rounded piece of metal in the radial slots, no go.  I'll attach a picture, you've no doubt seen it before; is there a special tool that engages the radiused slots?  The piece of metal that I used was a somewhat sloppy fit, wondering if I need to turn something exact on the lathe?  By the way, if you're wondering, I was able to turn the feed screw with a magnetic tool through the big end of the quill, to get it out of the way.  I could, of course, tap on the end of the screw and try to force the quill out, but I'm not sure that's in the best interest of the feed screw threads.  And after soaking in WD40, the quill lock is still stuck.

For a machine that's relatively unworn and not rusty in the least, it's just fighting me every step of the way.


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## RobertB (Nov 11, 2019)

Try some heat around the endcap. Wrap some fine (like 400 grit) sand paper around the endcap, grit against the cap and grip it with some channel locks. With some heat they usually break loose pretty easy. Get something better than WD-40 for penetrating oil, like Seafoam or Kroil.


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## paul s (Nov 12, 2019)

I Kroiled it, didn't make a difference.  Here's what I used - turned it on my South Bend, a "coin" 1.125" dia. 0.125" thick.  The thickness was a perfect fit in the slots, I think the diameter could have been a little larger.  Still took a fair amount of force with a large adjustable wrench.  When I got it out, there were metal filings in the threads.

I was able to tap the quill out with a brass drift, still can't get the lock out.  I've tapped the ID of the upper lock to 5/16-24 (it fit well enough without drilling).  I can lift the entire tailstock by the tap, so I'm not optimistic as to the lock coming out peacefully, but I'll get a 5/16-24 fastener and try the slide hammer.


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## RobertB (Nov 12, 2019)

Now that you have the quill out you can Kroil the inside ends of the locks. You can use a 3/8" or 1/2" drive socket that is just large enough for the lock to fit in and use it as a puller base. Thread the bolt with a washer under its head through the socket into the tapped lock and tighten to pull. If the lock didn't rotate when you were tapping it, it may be quite stubborn coming out.


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## paul s (Nov 12, 2019)

RobertB said:


> Now that you have the quill out you can Kroil the inside ends of the locks. You can use a 3/8" or 1/2" drive socket that is just large enough for the lock to fit in and use it as a puller base. Thread the bolt with a washer under its head through the socket into the tapped lock and tighten to pull. If the lock didn't rotate when you were tapping it, it may be quite stubborn coming out.


Good idea - better and easier than the slide hammer.  I'll try some Kroil, but I'm betting that I'm dealing with swollen Zamac.  And no, it didn't try to rotate while being tapped.


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## wa5cab (Nov 12, 2019)

That is probably the best way to break the upper lock/lock sleeve/sleeve loose from the tailstock.  But after 2 or 3 turns of the wrench, it will probably begin turning in the hole instead of the bolt threads continuing to extract it.  When that happens, shift to the slide hammer puller.  Then use the slide hammer puller and the original bolt that is still in the hole to remove the lower lock.


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## paul s (Nov 14, 2019)

Success!  The puller idea worked very well, a bolt, a washer, and a socket.  I knocked the lower one out with a drift and hammer.  There did appear to be some corrosion where the lower one sat.  Onward and upward.


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## paul s (Nov 17, 2019)

Found an inconsistency - I don't believe the bolt for the tailstock quill lock is correct.  The picture below shows that the square on the carriage bolt is much too small to engage the square in the lower lock.  The drawing I have shows 1/4-20, 1 5/8" long, square head.  It seems that either would work - I'm not really sure why the square would need to engage the lower lock.


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## RobertB (Nov 17, 2019)

That should be a square head bolt, not a carriage bolt. The bevel on the lock against the quill prevents it from turning and the square head in the recess prevents the bolt from turning. Being keyed to a fixed position also allows the lock lever to always lock in the same orientation. You can use one of 4 positions. If you are right handed, having the lever to the right when tight is most convenient.


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## paul s (Dec 9, 2019)

I ended up grinding down a 1/4-20 square nut to fit the recess, then fixtured it to a 1/4-20 bolt with the head cut off, using loctite.

I've got the tailstock and the headstock back together.  I replaced some of the backgears; regarding the pins that hold the eccentrics to the backgear shaft - they're set flush with the shaft, removing them entails tapping them out from the recessed side towards the flush side.

I've got the countershaft apart now and noticed something odd; I don't see any provision to get the oil from the gits oilers to the bronze bushings - no holes, slots, nothing.  Were these resleeved at some point?

On edit - these are oilite bearings and the oil will actually seep through?


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## GrayTech (Dec 10, 2019)

Bushings probably replaced and never drilled. Just drill them. I found the same thing on a lathe i repaired.


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## RobertB (Dec 10, 2019)

paul s said:


> On edit - these are oilite bearings and the oil will actually seep through?



Yes. the oil will seep into the oilite.


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## wa5cab (Dec 10, 2019)

Although it doesn't ruin anything to match drill a hole through the bushings after they are installed, it isn't necessary.  Oil the shaft itself during assembly and fill the cups immediately after assembly.  Then top up the oil in the cups when necessary.  The consequences of drilling a hole through the bushings is that you must thereafter re-fill the cups before every use, and the countershaft will tend to sling oil for the first few minutes after start up.

For those of you who don't recognize what;s being discussed, note that some countershafts have straight roller bearings and use grease, some have only sintered bronze bushings and use oil, and some have a combination of bushings and sealed ball bearings.


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## RobertB (Dec 10, 2019)

wa5cab said:


> ...and the countershaft will tend to sling oil for the first few minutes after start up.



and the biggest downside to this is it is likely to end up on your belts


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## paul s (Dec 10, 2019)

Thanks all!


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## paul s (Dec 12, 2019)

I've broken down most of the carriage/apron and found that the half nut guide has a hairline crack that runs from the hole where the spring and ball impinge, to the edge of the casting.  Is this something I can live with?  Can it be repaired?  Or should I look for a replacement?

This lathe only has power on the crossfeed, not on the longitudinal (other than using the halfnuts) - do I have that right?

The last part left on the apron is the handle/gear/shaft for the power crossfeed - the pin came out easily, the handle not so much.


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## wa5cab (Dec 13, 2019)

No, there is no practical way to repair the halfnut guide.  Yes, I would replace it.

Your 2nd paragraph is either incorrect and poorly worded or correct but poorly worded.  It is incorrect in that it does have power feed capability for both longitudinal and transverse (cross-feed) drive.  It is correct in that longitudinal drive for both turning and threading is provided by the Acme threaded leadscrew and the halfnuts.  Much more expensive lathes have two methods of longitudinal drive.  The lead screw and half nuts are only supposed to be used for threading because it maintains the thread accuracy for much longer.  For turning, the carriage is driven by another drive shaft through a gear arrangement that is conceptually similar to the cross-feed drive.  However, whether this is actually money well spent or not is subject to argument.  My attitude toward the  question (which would almost certainly be ignored or overridden by the sales department if I were running the engineering department of a lathe manufacturer) is that a lead screw, half nuts and the gears to drive them are almost certain to be cheaper, simpler  and more reliable than the drive mechanism including drive shaft and second set of gears.  So if the lead screw and half nuts need to be replaced in order to maintain threading accuracy, just replace them.  You still save money.  And the machine is automatically more reliable because it has fewer moving parts.

What's the problem with removing the cross feed knob?


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## paul s (Dec 13, 2019)

I was thinking that the crack in the halfnut guide is constrained by virtue of a pin on one side, and a threaded fastener on the other.  Initially, I thought replace it, but once bolted down, I'm not sure that crack can open up.

Don't know - I think the knob is just on there very tight.  I may end up leaving it and cleaning around it.


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## wa5cab (Dec 13, 2019)

OK.  If the guide looks like it would remain in place even if the crack were to propagate  across the part, and if the half nuts are not sloppy in the guide, then leave it.  

If none of the parts that you would have to remove the shaft in order to change look like they need to be replaced, then put the pin back in and leave the knob and shaft in place.  You might damage the knob or something else getting it off.  Then you would have to find a replacement for that or those parts before you could put it back together.


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## RobertB (Dec 13, 2019)

I would think about replacing it. I think you are correct, the crack would be held together once reassembled, but I would be concerned about the corners being broken off of the hole




I would think this may allow the detent ball to wander out of position and cause problems.


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## paul s (Dec 13, 2019)

Here's a picture where I've circled the crack, it's very faint.  The crack has already propagated across to the edge, and it's all the way through.

I saw a picture of another casting - the hole for the detent ball is drilled similarly.  It's so close to the edge, that breakout is unavoidable, I suppose.


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## markba633csi (Dec 13, 2019)

Hi Paul- you're at the point now where the truly devoted Atlas owner whips out the milling machine and makes a whole new part from scratch, adding additional material where possible to strengthen the weaknesses in the factory design.  Then he installs said part where no one but him will ever see it and appreciate the back-breaking and Herculean design effort he put forth.
If you are not quite so devoted and perhaps a little more sane, you go to Ebay and buy one. 
Mark


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## paul s (Dec 19, 2019)

Still working on the apron, now dealing with the thread dial.  It's got a "rough" spot in its rotation, so I'm trying to take it apart for cleaning.  I pressed the gear off, didn't expect a knurled shaft - it won't fit through the body.  I'm assuming that the dial portion presses off?


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## wa5cab (Dec 21, 2019)

Yes.  But no one that I know of has reported as to whether or not the top of the shaft is also knurled.


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## wa5cab (Dec 21, 2019)

The lower gear looks to have the tips of the teeth worn a little bit.

If the Locktite treatment doesn't appear to work, you could mount the bushing on an expanding mandrel and run a knurling tool over it lightly to increase the effective OD 2 or 3 thou.


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## paul s (Dec 21, 2019)

I didn't think about that - I guess they could have put the shaft through and knurled both ends in place.  That's a dirty trick.


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## RobertB (Dec 21, 2019)

wa5cab said:


> Yes.  But no one that I know of has reported as to whether or not the top of the shaft is also knurled.


I wonder if this design changed over the years. I don't recall having to take the dial off to get the shaft out, but then again it has been so long I don't even remember if mine was knurled on the gear end or if the knurl was just a snug fit going through the bore.


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## wa5cab (Dec 22, 2019)

The gear and the dial on my 3996 are pressed onto the shaft.  But I do not know whether either end of the shaft is knurled.  I don't know how other than a press fit you would hold either one in place.  The shaft itself is much too small for any available key type.  As to how it was done on earlier machines, I have to admit that I happen to own the newest lathe in the database.  I bought it in early 1981, just before production ceased.  But I don't think that the part numbers of the three parts ever changed.


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## RobertB (Dec 22, 2019)

I would try carefully tapping the shaft out of the dial. Tap it until it just barely starts to come out of the dial and check and see if it feels like it is binding when you rotate it. If not, tap a little farther out and check again. Rinse and repeat. If it feels like it is binding stop and see if you have gained  enough of a gap between the dial and the body to see if the shaft is knurled.

On the 6" lathe it is just the opposite, the dial end is knurled(splined) and the gear end is smooth.


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## paul s (Dec 27, 2019)

Only the gear end is knurled.  I suppose I have to re-index this on the lathe?


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## wa5cab (Dec 27, 2019)

OK.  That;s useful to know. 

Yes, the dial has to go on last.  If you have a drill press, I would suggest chucking the shaft in its chuck and using the quill down feed to try to get the shaft started into the gear straight.  If you can see the spline marks in the bore of the gear, try to align the splines an the shaft with thise in the gear.  Then use a press, not a hammer, to push the shaft into the gear.  When you put the dial on the other end, leave about 0.005" end float.  

Ideally, when you get the dial back on, using the "1" mark as the reference, it should be misaligned with the witness mark by the same amount when running the carriage toward the headstock as when running it toward the tailstock, but of course on the opposite side of the mark.


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## RobertB (Dec 27, 2019)

paul s said:


> Only the gear end is knurled.  I suppose I have to re-index this on the lathe?



To index it, after you have the gear back on the shaft place the assembly back on the lathe and engage the halfnuts. Then just push the dial on enough with your fingers to hold its position with the marks aligned. Remove the assembly and finish pressing on the dial. (Squeeze in a vise if you don't have a press)
As wa5cab said, make sure you leave a little clearance. There are no shoulders on the shaft so if you press it together too tight it will bind.


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## paul s (Jan 8, 2020)

OK - I've got the apron, the cross slide, the compound, the banjo/gears, the headstock, and the tailstock back together, cleaned and lubed - I'm in the home stretch.

I'll attach a picture of the motor - is this original to the machine?  It's got a cord and plug coming out of it, a switch at it's base - looks more like something from a bench grinder.  The shaft is 1/2" diameter, the pulley (10-428) is 5/8" bore, with an adapter on the motor shaft that looks home made.  The headstock has an on/off switch.  I don't care about being able to reverse it, so how would this have been wired originally?  I also noticed the PN of the pulley in my pdf is 9-428.


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## RobertB (Jan 8, 2020)

Don't know on your particular model, but Craftsman used that motor on a lot of the power tools they made, everything from drill presses to band saws. That is one of the best motors they ever used and the HP ratings on motors back then were more conservative than now. The only downside is they use a flat capacitor in the base that is no longer available. When they go bad you have to do some adapting to replace it with a modern round or oval one. At some point they changed to 5/8" shaft motors and for a lot of their tools afterwards if you bought a replacement motor pulley it would be a 5/8" bore and come with a 1/2" sleeve so you could use it for either shaft size. The quirky thing about them was the power switch, when used on a drill press, up was "on" and down was "off".


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## wa5cab (Jan 10, 2020)

Up = ON and Down = OFF is standard in the US and reversed in the UK.  The motor, from the 6.7 FLA shown on the nameplate is a 1/3 HP.  The buggered up keyway needs to be dressed so that the pull is a slip fit onto the spindle.  And don't ever run it without the square key (probably 1/4") in place.  You can see a circle at the bottom of the keyway which shows that some dummy put the pulley on without a key at some time in the past.  That may also be what caused the damage to the shaft.


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## paul s (Jan 10, 2020)

Keyway?  The shaft is 1/2" diameter with a flat on it.  There's a sleeve on the shaft to adapt to the 5/8" bore pulley.

I'm just wondering if any of this is original to the lathe?


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## wa5cab (Jan 10, 2020)

OK.  But the motor pulley has a keyway broached in it.  Which is standard for all of the 5/8" bore pulleys.  In that case, the proper installation would use a 1/4" wide key, with the other dimension ground or milled to be a slip fit.  Probably around 5'16".  Having 1/4" of set screw sticking out is just asking for a damaged motor shaft.


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## RobertB (Jan 10, 2020)

paul s said:


> I'm just wondering if any of this is original to the lathe?



They sold lathes (and many of their other power tools) without motors for those that wanted to supply their own. 
The era of that motor appears to be early to mid 50's (look for a stamped date code on the label) so would have been available the same time as your lathe.

In the 50's and 60's there were an awful lot of Craftsman tools powered by old washing machine motors.


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## paul s (Jan 10, 2020)

wa5cab said:


> OK.  But the motor pulley has a keyway broached in it.  Which is standard for all of the 5/8" bore pulleys.  In that case, the proper installation would use a 1/4" wide key, with the other dimension ground or milled to be a slip fit.  Probably around 5'16".  Having 1/4" of set screw sticking out is just asking for a damaged motor shaft.



Good point - the pulley did have a bit of a wobble before I pulled it off.  Having a key might mitigate that, certainly couldn't hurt.

I'm guessing that the previous owner must have used the switch on the motor, reaching all the way around the headstock, since the motor has a cord and plug on it, uninterrupted.


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## wa5cab (Jan 10, 2020)

If the motor switch is the only currently working switch, I recommend  hooking up the headstock mounted switch and just leave the switch on the motor in the ON position.  Reaching over or around the headstock is just asking for trouble.


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## paul s (Jan 10, 2020)

Agreed - I'll need a junction box then.  Wondering if I could use the motor itself as a J box - the cover plate has three holes on it's perimeter that are appear just large enough to accomodate a piece of SO cord.


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## RobertB (Jan 10, 2020)

Things are a bit cramped in there, but it is workable.




Another option would be to remove the switch from the motor, find a suitable grommet for the hole and run the wire through there to the headstock switch.


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## wa5cab (Jan 10, 2020)

Subject to where the motor mounted switch is located, that might be another way to do it.  However, if you have rug rats or other knob twiddlers around, the motor mounted switch might be treated as a safety measure.  Whenever you are done wtih the lathe, turn off the motor mounted switch.  Someone just walking by who has an irresistible urge to flip the headstock mounted switch and does so will be rewarded with nothing happening.

If you do decide to tie the headstock mounted switch into the motor and leave the motor mounted switch in place, identify the hot wire coming from the switch.  Disconnect it from its terminal and splice it to the black wire going to the headstock switch.  Connect the white wire coming from the headstock mounted switch to the terminal from which the wire from the motor mounted switch was removed.  And connect the green wire in the cord from the headstock mounted switch to some convenient grounding point at each end.


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## paul s (Jan 10, 2020)

RobertB said:


> Things are a bit cramped in there, but it is workable.
> 
> View attachment 310160
> 
> ...


That's a great idea - and there's probably enough room in the base for some strain relief.


wa5cab said:


> Subject to where the motor mounted switch is located, that might be another way to do it.  However, if you have rug rats or other knob twiddlers around, the motor mounted switch might be treated as a safety measure.  Whenever you are done wtih the lathe, turn off the motor mounted switch.  Someone just walking by who has an irresistible urge to flip the headstock mounted switch and does so will be rewarded with nothing happening.
> 
> If you do decide to tie the headstock mounted switch into the motor and leave the motor mounted switch in place, identify the hot wire coming from the switch.  Disconnect it from its terminal and splice it to the black wire going to the headstock switch.  Connect the white wire coming from the headstock mounted switch to the terminal from which the wire from the motor mounted switch was removed.  And connect the green wire in the cord from the headstock mounted switch to some convenient grounding point at each end.


Green wire?  No such animal here - hadn't been invented yet, apparently.


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## wa5cab (Jan 10, 2020)

OK.  As you didn't mention it in any detail, I was assuming that the 2-wire cord or the two loose wires in flexible conduit (BX) was missing and that it would be a new piece of 3-conductor.   If the BX is still present, I doubt that it will fit into one of the three holes that the photo shows.  What do you have?


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## paul s (Jan 11, 2020)

wa5cab said:


> OK.  As you didn't mention it in any detail, I was assuming that the 2-wire cord or the two loose wires in flexible conduit (BX) was missing and that it would be a new piece of 3-conductor.   If the BX is still present, I doubt that it will fit into one of the three holes that the photo shows.  What do you have?


The motor has the typical sj/so cord coming out of it, with a two prong plug.  That's why I'm unsure of how this thing was being powered on, other than using the switch on the motor.  The lathe came out of an estate in Denver, I never met the owner, or saw it being used.  The headstock switch has a short piece of so/sj cable attached, with bare wire on the end.


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## wa5cab (Jan 11, 2020)

OK.  The motor power cord is probably original 70 odd years old.  The cord to the front switch is probably the same age but may not be original as the few that I have seen photos of were usually in BX flexible conduit.  For safety, both should be replaced with new 3-conductor SJOOW 300 VAC rated.  And the plug should be replaced with a 3-pin one.  Wire gauge should be the same as the original.

You only need to identify the wire that comes from the switch and that is not connected to anything else internally.  It is, unfortunately, possible that there is no such wire under the cover plate.  In that case, you can't run the wire to the front of the headstock out of the junction box without taking the motor apart, and knowing what you are doing.


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## paul s (Jan 21, 2020)

Still at it - trying to replace the motor bearings, which are quite noisy.

The motor cap without the centrifugal switch comes off easily.  The one with the switch, is constrained by wires, of course, and the bearing on that end prevents the armature from pulling through, as the hole in the centrifugal switch is not large enough.  I can pull the armature towards the switch end just enough, I think, to get a puller/bearing splitter behind the bearing on that side.  Is that how this has to be done?


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## wa5cab (Jan 21, 2020)

It is many years now since I last needed to pull the armature out of a capacitor start motor, but I do not recall ever having to pull the switch end bearing in order to extract the armature.  That being said, it does sound as though your motor is different.  And that you will have to pull the bearing first.  It might be wise, once you have the bearing off and the armature out of the way, to inspect the switch and see whether the hole through it can be enlarged just enough to get the bearing through.  I would assume that you will have to disconnect the switch from the wiring in order to do that, though.


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## RobertB (Jan 21, 2020)

You should be able to push the whole armature out of the switch end cover all the way through the motor, the bearing should stay in the end cap. If you have a puller that will fit in the slots on the cover near the bearing use that. If no puller, you can put the open end up on blocks with the edges of the iron core on the blocks and the shaft free to drop an inch or so then tap on the other end of the shaft with a soft hammer or wood block to drive it out of the bearing. (be sure and clean any rust off of the shaft first) If my description isn't clear enough let me know and I'll cobble together a drawing to explain it better.


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## paul s (Jan 21, 2020)

Done - used a bearing splitter/puller, enough space to fit it between the back of the bearing and the end housing.  Now, off to source new bearings - do they have to have the shoulder on the inboard side?


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## RobertB (Jan 21, 2020)

If yours has the New Departure 8502 bearings, the modern equivalent is 87502. They are not a very commonly used size so they are usually expensive compared to similar size bearings, $15 or so each. It may be worth trying to clean and lube your existing ones, there may just be old crud in them.


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## paul s (Jan 21, 2020)

They're 87502 - can I substitute a 6202 and make a spacer to account for the lack of shoulder?  Given the flat capacitor that's made of "unobtanium", I'd like to put as little as possible into this motor.


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## RobertB (Jan 21, 2020)

Likely they have been replaced already then. You should be able to use a spacer, the bearings in these have a bit of leeway. One bearing is fixed and the other end "floats" a bit, being held lightly by a wavy washer.


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## paul s (Jan 24, 2020)

Ordered two Koyo 6202 bearings from thebigbearingstore.com - $11.44 including 1st class mail shipping.


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## paul s (Mar 3, 2020)

I'm still on the job here, have a new issue:  The two miter gears in the apron were stripped badly.  I found both on ebay, but the one I bought that rides on the leadscrew has a thin ridge, where the cast in key should be.  I've searched and read here regarding sheared keys, but the strange part is that there's no evidence where the base of the key would have been, that it had ever been there.  Unless action from the leadscrew wore the ID smooth, so as to remove any jagged traces.  It almost makes me think that it was intentional, like a shear mechanism to protect the gears.  The other notable difference, is that the original gear had a steel wear liner, apparently cast into it.

I have a broach, I suppose I could broach, insert a new key and secure it.  Also, wondering about the possibility of cutting/turning the original gear off, cutting the new gear section off its "shaft" and mating the good gear section with the original shaft.


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## wa5cab (Mar 3, 2020)

I don't know what it would look like "in person" but in your photo appears a dark line approximately where the right side of the cast-in key would have been.  My guess would be that it never got lubricated.  I would attempt to return the gear as worn out or defective.  It would be better if you had a new gear to photograph to prove what it should look like.


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## paul s (Mar 4, 2020)

I just messaged the seller, sent a picture, along with a picture of the original, which has the key intact, although the teeth are all sheared off.


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## paul s (Mar 4, 2020)

By the way, installed the two new motor bearings yesterday, along with some 0.064" thick spacers I turned, to make up for the difference in bearing thickness.


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## wa5cab (Mar 4, 2020)

Well, good luck on the gear.

I just reread several posts back about the motor bearings.  Were the original bearings flanged instead of plain?


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## paul s (Mar 4, 2020)

Yes, they were.  The Koyo bearings were less than half the price, and the spacers were easy enough to turn.


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## paul s (Mar 4, 2020)

The seller refunded my money and told me to keep the part.  So, I've got nothing to lose - should I broach a key way?  It'll extend through one of the gear teeth, not sure if it'll make much difference.

Got the motor back together today with the new bearings.  There are two flat compression type springs on one end - I'm pretty sure they were both oriented in the same direction (they're not symmetric).  Can anyone here confirm?


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## paul s (Apr 9, 2020)

Still on the job, here:  The original apron miter gear had sheared teeth but a good key; the ebay one had good teeth, but a sheared key.  I combined the two, sleeving them together and securing with Permatex sleeve retainer. Since I didn't want to thin out the area under the gear too much, the part ended up a bit longer than the original, 1.962" vs. 1.745".  There's enough clearance in the apron, that the gear could be almost 1/2 inch longer than it is.  As a bonus, I retained the full length of the key.

Meanwhile, the 2 step motor pulley has got quite a wobble - I thought it was the shaft reducer on the motor.  I turned down a piece of stock in my other lathe to a tight slip fit for the pulley bore and spun the pulley on the lathe - same wobble.  I don't know if it would work to true it up or not, I suppose I would have to use an expanding arbor, but I would end up changing the profile of the v section.  So, I've got a nice cast and machined Browning pulley that fits, runs fairly true, but it's single step, somewhere between the two original steps.  I calculated a top speed at the spindle of roughly 1200 rpm, which should be enough, although I know original is closer to 2000.  At the bottom, I suppose back gear will take care of things.


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## paul s (Apr 14, 2020)

What's the correct orientation for the bearing dust cover -
	

		
			
		

		
	



	

		
			
		

		
	
 semi-circular cutout on top and aligned with the oiler?


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## wa5cab (Apr 14, 2020)

Yes,  The oil has to be able to get through to the bearing.  And same with the rear oiler.

And never ever put grease on the spindle bearings.  Murphy says that the probability that it will block the oil path approaches 1:1.


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## paul s (Apr 19, 2020)

I'm just about done - got the thread dial back together and indexed correctly, got the countershaft and motor mounted, leadscrew cleaned and installed.  Have a little issue with the right hand leadscrew bracket, though.  With the stack up of spacers and thrust bearings, when the two jam nuts are installed, the leadscrew shoulder on the left hand side doesn't snug up against the bracket.  Is something amiss with the number or size spacers?  Just want to make sure I'm not overlooking something, before I go off modifying or making spacers.

The spacer that I'm holding in my hand is one that was mounted on the RH side bracket assembly, which when included, leaves the right most jam nut with only about 1/2 the threads engaged.


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