Turntable speed accuracy

I picked up a Timeline as I was interested in how our Scully Lathe was doing while cutting lacquers.

The Scully uses a 1/8 horsepower Bodine AC synchronous motor, driving a transmission that then drives the platter via a drive shaft.

With the cutterhead cutting on the plate, the laser does not move- over the entire side you can't see the change even when you use a micrometer. Not bad for being built in the 1940s :)

Atmasphere - think of all the "wear and tear" of all the drive train over 70 odd years. I think whilst we have gained in technology, we have probably lost ground in metallurgy, it's the age of junk metals ( PC & non toxic manufacturing processes required ). I still marvel at the lack of main bearing wear in the Final TT which is now over 30 years old.
Love to hear playback via a lathe and good old Mcintosh MI200's that I lusted after years ago.

Lewm - distance from wall is 400mm if you want to do the maths.

Henry - just to say thanks for the inspiration - your video challenge has really upped the game for die hard analogue folk.

Dear Dover, I don't. But I am surprised you were even able to perceive (visually) a 2-mm displacement, although I guess over time you could measure a larger distance and then extrapolate backwards to determine 2mm per revolution.

Lewm - I positioned vertically a silver metal marker, about 25mm wide, on the wall - it was quite easy to check the moving distance from the leading edge.

Dover, it has been sitting for some decades, I suspect.

The trust bearings are interesting. They are a set of polished platforms that reside beneath the platter. The drive shaft comes through the center and has nothing to do with them!