Mini lathe problem

This is my first lathe and I am just a beginner and have been playing with the lathe for a while. I found that when taking a facing cut on my mini lathe (Chester Conquest) the cut is concave by about 0.07 mm in 20 mm. I have read that facing cuts should be slightly concave but this seems excessive to me. I am fairly sure that the head stock alignment is OK as it turns reasonably parallel. I have searched the internet and although there is plenty stuff on tuning lathes but not much on this problem. It seems to me that problem is that the carriage is out of alignment and either the V groove that runs on the bed or the dovetail for the cross slide could me attacked but which one and how? I thought that I could mount the carriage on the Conquest Mini Mill and run a dovetail cutter along the carriage but I am worried that I f**k it up completely. Any thoughts anyone?

Archie

Reply to
Archie
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Sorry. Wrong Group.

Reply to
Archie

Which one did you intend?

Reply to
Andy Hall

I'm sure someone on here will know enough about lathes to be able to answer your question.

sponix

Reply to
sponix

Your problem is either the slideways or the headstock alignment. Without knowing which one, anything you do could make matters worse. You need to address the problem not the symptom. Check the headstock alignment first. Do this by setting a long piece of straight bar in the chuck and, using a dial guage on the saddle, it should read the same along it's length as the carriage is moved from headstock to tailstock. If that's OK the problem may be that the cross travel isn't at 90 deg to the saddle. What you can do about any of this (if anything) depends upon the lathe. Personally, I would take it back to the supplier and explain the problem. The difficulty is that the manufacturers don't give any tolerances in their specs. At least, not on the web site I saw. You may find that they consider a taper of 1 in 300 acceptable.

Reply to
John

uk.rec.models.engineering.

Archie

Reply to
Archie

Are you by any chance dry-turning a plastic/nylon material.....something soft which also has a high coefficient of expansion as it heats up?

Reply to
Tony Williams

No. Just running a DTI mounted on the cross slide across the face of the chuck.

Archie

Reply to
Archie

But your original post used the words "when taking a facing cut"?

Reply to
Tony Williams

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