It's quite possible.

But that very tall magnetic stand anchored to the bench next to the bed with the flexible fine adjustment joint in the middle of the second arm could be flexing all over the place by several thou too.

A more stable set up might be to mount the clamp that holds the dial indicator gauge directly on the first upright bar of the magnetic base and then clamp the magnetic base to the lathe bed. The more direct the better. Whatever you do, get that fine adjsutment joint out of the equation. They have no place in precision measurement.

And I can't see exactly what you are measuring from there — the spindle itself or a piece of bar held in the collets, or something else. An overall view picture would help.

Edited By Hopper on 16/03/2021 03:17:42

Well if you are happy with your measuring process — I still have some mistrust of those flexible joints based on experience — then the answer is yes these lathes can have that little runout. Enjoy.

Edited By Hopper on 16/03/2021 04:51:44

Could the OP edit his first post so we know what the units are please, (2nd paragraph).

I presume the the lathe spindle is supported on plain bearings? If that is so then there will be some clearance so the bearing can be lubricated properly.

How where the measurements taken? Just by rotating the spindle, if so I would expect the results quoted. What about up and down/side to side movement? Try measuring with the DTI on top of the spindle and then gently lift the spindle, (simulating a cut) . I would suggest that the necessary clearance in the bearing would show if the measuring equipment is a s good as you suggest.

Also, some measurements after the the machines been running would be interesting.

John

It is good enough to make watches with. It doesn't need to be any better than tha so it simply doesn't matter what its absolute accuracy is. The quality is in the hands that use it.

Edited By Tom Sheppard on 16/03/2021 17:09:28

To a watchmaker it measures 0.00004432951''' but one such will be sensible enough to use microns which are a proper measurement and coincidentally, what the dial is calibrated to.

0.00004432951''', not 0.00004432951''. That is something completely different!

Is it the diameter of the head of a pin?

Having read the OP I thought I would see what runout my lathes would show. Here are a couple of shakey handheld videos. As I had a setup in the chuck of the Hobbymat I made the measurement on the chuck mounting flange. This is not very smoothly machined and as I realised afterwards it has an 0 stamped in it to position the chuck. The mearurements were made with a 1 micrometer resolution TESA indicator mounted on a Mitutoyo magentic stand. The runout is around 10 micrometers and I was not able to see any deflection with hand presure on the chuck.

**LINK**

I repeated this with my Proxxon FD150, this time measuring on the chuck register. It was difficult to get the indicator in place. The runout here was around 5 micrometers and I got a couple of micrometers deflection when pressing on the spindle nose.

**LINK**

Hoho. A watchmaking joke. Very droll. I'll pay that.

Interesting link. 1 ligne = a round wick folded over and measured. Whole different world those button makers live in.

Nope unless the Gladstone Pottery Museum has a pretend one, doubt any real ones are still living the way pneumoconiosis used to wipe out the old time potters.