New to me 5904

You could loosen the headstock and apply some shim stock on the flat side of the ways.
Note that there is a tapered pin on the front side near the vee way that pins the headstock to the bed.
 
Mounting the Edge test bar between centers effectively cancels out any height error hypothetically due to the headstock not being level. However, before doing anything, I would remove the test bar and slide the tailstock up to the headstock until the two centers almost touch. You should easily see any height error as large as 0.042". As another check to make sure that your MT taper in the spindle is not the culprit is with the two centers almost touching but not overlapping, rotate the spindle 180 degrees. Or alternatively, with the test bar in place, position your dial indicator back over the headstock end of the test bar and check the runout. Or both.
 
You could loosen the headstock and apply some shim stock on the flat side of the ways.
Note that there is a tapered pin on the front side near the vee way that pins the headstock to the bed.

Ya, Not sure I want to travel down that road quite yet. That could be a slippery slope!
 
I had the headstock off mine when I moved it. The tapered pin is in the front corner on the chuck end. Its going into the flat part of the way, not the vee as stated earlier (brain lapse). Easiest way to remove is to carefully rock/pry around the headstock (after removing retaining bolts).

Also, try turning your own center in a chuck as it will then be exactly concentric with the axis of rotation. (see pic).
center_homemade.jpg
 
Mounting the Edge test bar between centers effectively cancels out any height error hypothetically due to the headstock not being level. However, before doing anything, I would remove the test bar and slide the tailstock up to the headstock until the two centers almost touch. You should easily see any height error as large as 0.042". As another check to make sure that your MT taper in the spindle is not the culprit is with the two centers almost touching but not overlapping, rotate the spindle 180 degrees. Or alternatively, with the test bar in place, position your dial indicator back over the headstock end of the test bar and check the runout. Or both.

I executed what you stated and found the tail stock center clearly higher. I checked runout on the center I had in the head stock which is 3mt then an adapter to 4mt for the spindle. It has .003 in runout. I dI'd notice I can see daylight through the two halve of my tail stock...hmmmm? I should probably start there and take it apart for examination. 20200322_145832.jpg
 
OK. The tailstock is high. It wasn't quite clear to me where you were seeing daylight through the TS but as you probbly have a V-bed, it could have been designed that way. Or another possibility is that a shaving/swarf could have gotten embedded. Removal and inspection should show that.
 
Found my .042in! I did some research in the manual and it appears this tail stock is not original to the lathe by serial number. This particular tail stock goes on the later serial numbered lathes. I took the tail stock off today and it appears some brilliant human used the end of the stock as an anvil. Hammer marks all over it, under the spindle. They deformed the joint where the stock splits in two. I spend some time cleaning and stoning the surfaces. Reassembled the stock. Put a center in it. Slid it over to the head stock. Threaded out the spindle, and VOILA, money shot!20200328_123609.jpg20200328_123621.jpg20200328_123634.jpg20200328_135934.jpg20200328_142942.jpg
 
pretty crazy what people do to machine tools! glad you found the error and was able to fix it.
 
pretty crazy what people do to machine tools! glad you found the error and was able to fix it.

Thanks. I'm glad I didn't have to get into the headstock as you stated. When I saw the damage I had a fuzzy feeling it was going to be the fault.
 
Very nice Clausing Lathe. I have a 5903. I absolutely love it. Really a great machine.
 
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