Vintage DD turntables. Are we living dangerously?

For those of you that have platters that have a raised lip - it is a very easy job for a competent engineering workshop to remove the lip ( without upsetting the balance) which would enable you to run any platter mat, or alternately reduce the height of the lip so the record does not touch the aluminium platter.

Lew, re:
"I am surprised that one good oil would be noticeably superior to another good oil in a tt turning at most 45rpm", studying fluid mechanics would indicate that the toughest lubrication applications are slow speed as opposed to high speed where lubrication "wedge" can be easily generated by the fast moving parts.
That is why slow turning gears use high viscosity lubricants with extreme pressure additives to reduce wear and minute "welding" of the gear parts.
This is basic lubrication.
Viscosity is part of the equation. Another part is film strength and anti friction agents to support moving parts at high pressure.
The lubrication of a tiny ball bearing moving against a disc at slow speed is actually a tough application. It's like stilettos: The pressure of the bearing is fairly high (P=F/A) where A (area) is very small and F (force) is not insignificant and the slow 33 or 45 RPM is not sufficient to easily build a fluid film between the ball bearing tip and the disc.
A good lubricant can help since reducing friction in this point will benefit in less noise which transfers from the spindle to the platter.
Just my thoughts and personal experience.
Stop times are dictated by viscous shear (internal friction of the fluid layers) and asperity contact at the tip of the bearing. The higher the lubricant's film strength the less the asperity contact would be a factor and stop times will be dictated by viscous shear. That is why adding weight didn't really change our results with RP.

Nice Post Doron.....😘

Doron,

+1
I have read your post a couple of times. Made me think!
Thanks.

Halcro,

When your Acromat arrives, you will notice that it has square edges. Looking at the inside of the base of the raised edge on the platter, you will see that there is a slight radius. Because the Acromat's diameter is a tight fit when placed in the lip of the Victor's platter,this radius to square corner bothered me so I did slightly chamfer (bevel), the underside edge of the Acromat so that I wasn't worried about interference (the square corner riding a radius). I might have been overreacting to a possible non-existent problem but had I not done something, I would have thought about this for ever. Anyway, the Acromat sands very easy so take my comments only as something to consider.
Hope you like what it brings to the party! (grin)

Regards,