# New to me 101.21400 with broken parts



## Skinnywater (May 1, 2017)

Greetings. I have started disassembly of this lathe to see if it is able to be put back in working order. So far I found the tool holder on the cross slide was previously brazed back together,  obviously it will have to be replaced. The carriage travel gear is stripped and will also have to be replaced.   I found both those items on Ebay, but is there anywhere else I should look?

I "think" I need a new back gear, the manual appears to show these gears to be a single piece, mine is 2 separate gears with obvious damage to the edge of the small gear. Am I correct this should be a single piece?


----------



## westsailpat (May 1, 2017)

Parts here http://www.searspartsdirect.com/model-number/10121400/0247/0728000.html . When you say "tool holder" do you mean the top slide of the compound ? Mine was welded it's hanging in there . Also you can go direct to Clausing  to get parts . I have found EBay a good source , but be careful some guys are looking to make a killing .  How bout some pics ? Welcome to the machine .


----------



## kd4gij (May 1, 2017)

Sears is way over priced. Some parts are cheaper from Clausing  Then eBay  Best to shop around. And pic would be a big help.


----------



## Rob (May 2, 2017)

Yes give Clausing a call 269-345-7155 or 800-323-0972.  A lot of time the price for new is the same or cheaper than EBay.


----------



## wa5cab (May 4, 2017)

AFAIK, any parts that Sears would have or could get would be from Clausing.  Which is why Clausing would normally be less expensive.  However, I think that Sears did stock parts at one time so if they still have it, it could conceivably be cheaper unless their bean counters have periodically jacked up the price on older inventory.


----------



## wa5cab (May 4, 2017)

Also, on your implied back gear question, the 6" back gears (not including bushings) were actually made as two parts, the large gear, and the small gear and sleeve or tube.  And then pressed together and the bushings installed.  Later manuals only show a part number for the complete 4-part assembly.  Plus do show the bushing part numbers.  Perhaps they had too much trouble with damaged parts when owners tried to hammer them together.


----------



## Skinnywater (May 8, 2017)

Thanks for the info on the back gear.
I spent the weekend cleaning up the spindle and ways so that I could check the run out. First off, I pulled the made in China 3 jaw chuck off and the back plate so I could get a true reading on the spindle. With an inexpensive dial indicator, I was seeing .003" runout just behind the threads on the spindle, and no slop or movement in the bearings. With the back plate and chuck installed, total runout was over .030.
If I find the rest of the lathe salvageable, should I get a direct thread 4 jaw chuck, or try with another back plate and 3 jaw?
I am still digging into the counter shaft, lead screw gears and tail stock.


----------



## wa5cab (May 8, 2017)

There is one disadvantage to using a flat-back chuck with separate back plate, and that is that the resultant assembly will be longer (sticks out farther from the headstock) than one made from scratch to fit 1"-10 spindle threads.  But before giving up on the one that you have, I would try a few more things.  

First, make sure that the male and female threads are clean and lightly oiled.  Then check the repeatability by loosening the jaws and re-tightening, both with and without rotating the test piece.  Check the runout at at least two different diameters.  It should be the same.  Then check the runout at say 1" and 6" from the face of the jaws.

The back plate is attached to the chuck body with 3 or more screws.  Loosen them and see whether or not there is any appreciable movement between plate and chuck body.  If there is, see whether or not you can reduce the runout that way.  If there isn't, mark the hole for the screw nearest the #1 jaw as 1 with felt tip marker.  Mark the chuck body 1 to however many screws there are in the same order as the 1, 2 and 3 jaws.  Without removing the test piece from the jaws, remove the screws, rotate the body so that 2 on the chuck matches 1 on the back plate and repeat the measurements.  Repeat this operation for the other possible positions.  It is always possible that a PO took the chuck off of the back plate and didn't put it back on in the original position.

If you can, borrow another similar chuck and repeat the tests (except don't loosen the back plate screws!).


----------



## Skinnywater (May 8, 2017)

Makes sense, I will try rotating the chuck in relation to the back plate. One thing I noticed was that 2 of the three bolts screw in easily, and the third binds on the side of the back plate.


----------



## wa5cab (May 8, 2017)

That isn't a good sign.  That means that the holes in the back plate do not match with to the tapped holes in the chuck.


----------



## markba633csi (May 9, 2017)

Did you say the spindle itself had .003 runout just behind the threads?  That could mean a problem with the spindle itself (bent). 
I would try to get a reading on the inner taper if you can, or put a dead center in and check for runout.  
Mark S.


----------



## wa5cab (May 9, 2017)

Actually, on a 6", TIR of 0.003" isn't too far off of the mark.  According to a factory partial drawing that we have on the Atlas M6-81B Bearing, in between the two Timken numbers is written "CLASS 2 FIT".  According to ANSI-ABMA 19.2. the allowable "Assembled Bearing Radial Runout" is 0.0015".  If a PO replaced the spindle bearings with the cheapest things he could find (which would be normal for too many users) he probably got bearings that don't even meet Class 4 (0.0020") made you-know-where.

Also, according to one of the catalogs, the three-jaw chucks sold by Atlas and Sears would only meet 0.0050".  And the way in which the catalog ad was written didn't make it clear whether they meant 0.0050" TIR or +/- 0.0050", which would be .010" TIR..  So I would concentrate on getting the 3-jaw runout on an accurately ground gauge bar within that and for anything that needs to be better, use a 4-jaw.  And concentrate on the other issues.


----------



## Skinnywater (Jun 4, 2017)

Update, I have gone through the lathe, cleaned, lubed and reassembled it. In addition to replacing the carriage travel gears and back gears, I also need the following:
1.The pulley shaft is scored and the bushings are sloppy on the counter shaft.
2. Tailstock lock assembly is missing.
3. Questionable whether I can fix the chuck, or replace it.


----------

