[How do I?] "map" The Errors On A Older Lathe?

This lathe, but mine has a box pillar under the headstock with a door on it which gives access to the belt adjuster .
 
Hi Again, you posted while I was typing.............. we need to get the terminology clear here, most important. If you mean by "the diameter of the test cut being smaller at the chuck end of the test cut bar." You mean that the lathe removed more metal nearer the chuck, or to put it another way the diameter of the test piece is smaller nearer the chuck, and gets larger as you move away from the chuck. If this is the case this would more likely be a slight twist in the bed, which can be corrected, and would mean that if you stand at the headstock end of the lathe, looking down the length of the bed, the twist is clockwise, IE the vees get slightly further away from the centre as you move away from the headstock.. Embedded chips I don't like the sound of! Is there visible scoring on the Vees, if so as long as it doesn't cover the whole of the vee, the bed should not have dropped, and you can correct wear (to a certain small amount, by slightly twisting the bed in the opposite direction, but we are getting way ahead of ourselves here) can you post up some pics of the lathe, and some closeups of the bed, especially the areas you think are the most worn.
Phil
I will post some pictures tomorrow. I"ve been busy with family today. Just thought I would respond , you've been so kind to offer all this information. The vees are scored somewhat. The lathe did indeed remove more metal nearer the chuck. I am headed out to the shop to work on a side project, I will snap the photos for you. I have some of the saddle and ways posted in my album on the yahoo Rockwell Delta forum. Can you see those? If so I will add all photos there for future reference. My lathe is on a wood platform which is on a flat concrete floor. The lathe bed is bolted to sheet metal cabinets.

Thank You again.
 
No Ken, we don't, that is good work, and a machine that is as accurate as it needs to be, in fact probably more so! Of course you could try a .0015" shim under the front tailstock end foot....................................here we go again!!

Won't work on my lathe! It has a center leg in the equation. I could shim the center leg. I leveled it with a 199 level for twist only. I could have left a dip in the middle, I doubt it though. It's setting on a 3" slab at most, with fairly stable ground under the concrete. I sure if I had a lazer with readings down to six places, it would pick up me walking on the concrete! May even pick up into a tenth or two, walking across the concrete floor!

Anyways, getting way out of text here.
 
A centre leg! never thought of that, now that complicates things no end................................I think i feel a headache coming on!
Phil
 
Hermetic,
I could not create an album in this forum , got a server error. I posted some photos in the Yahoo Rockwell Delta Forum album under "John Wrights Rockwell 14". Can you see those?
 
John,

The wear you're showing in your pictures, is about the same wear I have in my 58 year old 13" Sheldon Sebastian lathe. Really not bad! Could be better. I just live with the wear. I do have intentions of rebuilding the lathe in the near future for the second time since I've had it. For me, there's a place in Dallas I can take the bed to and have it reground for a start. Just realized you are over in Mississippi. I don't know if there is anyone closer to you or not? If you want to have the bed reground, I can give you some direction on getting it done and shimming and scraping and fitting the saddle to the freshly ground bed.

edit: BTW, my Rockwell lathe may be in a little better shape than yours as for the bed. Now the rest of my lathe may not be.

Thanks for sharing.

Ken
 
Here's some pictures of the "mapping out" of the wear on my L & S bed before and during grinding. I made a "sled" that ran up an down the bed tracking on areas that are not worn by the saddle or any other equipment on the lathe to map out the wear on the bed, similar to what John has done.

I also used this sled to do the grinding on the bed too.

DSCN0588.JPG DSCN0589.JPG DSCN0638.JPG DSCN0640.JPG
 
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