Enco 13x40 Spindle bent or headstock mis-aligned?

For those interested, I am going to post the instructions that Richard sent me and others his method of tailstock to headstock alignment as well as the evaluation of one other occasionally used method that he had heard about. I will post this under a new thread in the Machine way scraping and restoration though it might be better in the Metrology section, but Richard doesn't moderate that one, and since it could go under others that's just where I'll put it. If anyone knows how to make it an article, it would be good to do that. Anyway check this link here to get to the method he uses:

http://www.hobby-machinist.com/show...-Tailstock-with-Headstock?p=106737#post106737
 
I have read through this thread with some interest.

The observation is that when work is held in the headstock only (No Tail stock center) and turned results in a shallow taper being observed.

Step #1 Check the level of the machine right to left and front to back at several positions along the bed. Use a precision machine level with a graduated vile to measure.
Step #2 Shim the machine legs to get the machine level.
Step #3 Make a test cut ( two disks attached to a shaft reduces cutting time).
Step #4 From now on the shimming is at the tail stock end of the bed only. If the tail stock end of the test piece is large, shim the front right leg. If the headstock end is large shim the right rear leg.

The issue is caused by an out of level condition twisting the bed ever so slightly.
I cant advise how much to shim, as several variables are at play, amount of correction required, bed length, and what foundation the lathe is on are the most important.
 
Barry's head stock has a pivot under it and after he had the lathe bed level he turned the head-stock to get the alignment correct. I would also set the level on the top of the cross-slide and make it level with the earth by placing a feeler gage under one side or by turning the leveling jacks or shimming in the old lathes that did not have leveling screws. In some older South Bend Lathes I would tap the hold down bolts or drill and tap leveling screw holes 5/8 fine thread near the hole so no shimming is needed.

Lathes do not need to be leveled, but the ways need to be Parallel to each other As some other and I have always said, how do you leverl a lathe on a Aircraft carrier or a Slant bed lathe? You don't but you ude a level that is attached to the cross-slide that is level with the earth and move the saddle to check for twists in the bed. This way you are also checking the invisible tool path. In some cases you can adjust the bed in a twist to compensate for wear. This will affect boring a hole and tail-stock alignment. Many will shim the head-stock, but I never recommend this.

If you can't twist or tweek the bed then you need to rebuild the machine. You can also mount a mag base and indicator on the crosslide / compound or a indicator mounted in the Aloris tool post with the indicator on the tail-stock end collar (you say disk) and I find that you move it 1 to 1 on the indicator as you shim, turn the head or adjust the leveling screws. So if the outside TS end collar is big by .002" when you mic, then you adjust the front TS leveling screw down to lift the bed and the indicator reads .002+. Then re-cut the bar again. It's a trial and error method that works quit well.
 
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