Turntable speed accuracy

Speed is also NOT of utmost importance to me.
I do nor 'suffer' from perfect pitch, and am glad I do not.
So n problem for me. Whatever the speed as long as it is reasonable I am fine.
So 31 rpm is probably not reasonable here... Just to fend off jokers..

I have the Kab strobe disc and laser pointer which I have used reliably for the last two years and I have now just obtained the Sutherland Timeline laser weight.
The Timeline demonstrates that the Kab strode is merely an 'approximation' of correct speed.....or at least is not capable of detecting instantaneous 'stylus drag' which is clearly visible with the Timeline.
I can assure anyone......that once you have heard a record played without stylus drag.......speed constancy will become an important factor in your vinyl experience :^)

What Viridian said and Halcro hinted at. More important is stable speed regardless of groove modulation, as opposed to bang on 33.33 rpm. If a table can stay at 32 rpm whilst tracking any and all passages, then it could probably be adjusted to run stably at 33 rpm, so absolute speed is less of an issue, IMO. I read a very insightful piece somewhere on the internet last week which pointed out that the turntable provides fully "half" the music, as its speed past the stylus provides the horizontal axis of the complex sine waves that represent music, if it were graphically displayed for example with an oscilloscope. The cartridge can only give us the other half, the vertical or amplitude direction. All musical timing must come from the tt. Pretty sobering, eh? Well, I knew that, but I had never thought of it that way.

Quite right Lew.
It really doesn't matter if your TT is revolving at 32.4rpm or 33.3rpm (other than pitch)......as long as it it is unwavering!
And that article you read was the one I posted by Peter Moncreif of the IAR. It was like a thunderbolt for me. The man is a real thinker :^)......in a field where there are some stinkers :^(

The turntable speed should be at least as accurate as the tape recorders used to record, master, and playback the tape.

Constant speed is "much more" important than absolute speed.

Just buy a strobe disc and illuminate it with a light bulb.

The 60 Hz AC frequency does not fluctuate enough to worry over.

Adjust the speed of your turntable, or AC input (if you have a variable frequency supply like VPI SDS) for the lines or dots to appear stationary or slightly vary around a fixed position.

This is simple and more than sufficient. Tape decks are not all that accurate, and do go out of spec.

On my VPI TNT the SDS AC line frequency is set within .01 Hz.

If your platter is heavy, playing a record will not affect the speed.