@cjaronica Order several. Soft and medium and then you can try both. Measure all parameters like inner/outer diameter and thickness. Red color silicone ones are very high quality.
Silicone is fairly soft and stretches. I would order one size as close as possible to what you measure and maybe another one a size smaller.
They also carry o-rings made out of just about any rubber material. Prices are cheap and most items are in stock. It's a great place.
I have a TTW GemV2 with a 42 pound copper platter. This was a demo unit. I did get a brand new momentus motor and speed control.
if the motor pod is set too tight to the platter you will get motor vibration. tap it out a bit just so it drives the platter. try and dress the oring with 1000 ,1500 grit emery paper. the more accurate the diameter, the more accurate and consistent the speed will be. make sure the pulley is locked tight to the motor shaft, any wobble there will cause improper speed.
I actually changed the drive unit to the Teres Verus pod and controller One of the best things I did for this table.
So here is a cheap tweak :)
The Teres uses two little pads set off the centerline under the motor pod. this allows the pod to lean into the platter using gravity to maintain an even consistent pressure. dressing the oring is much simplified as you just stick the emery between the platter and drive pulley, letting gravity apply the pressure. this results in accurate and consistant speed with all the goodness that comes from that.
Using the same principle of the Teres motor pod, I used 2 kitchen cabinet snubbers, those half moon stickon things you will find on most cabinet doors to cushion the impact of door to frame, just off the center line of the pod and let the pod lean into the platter, like the Teres system.
More accurate and consistent speed control with simplified oring dressing.....sweet !
Now you do say "orings..does this mean you have the double oring spindle", or is it single ? mine is single, so the tweak is easy. with the double it would be slightly harder, but still worth it to try .
I have a TTW GEM Ultra table and found some O-rings on amazon.ca that I have just started to use.
014 Buna-N O-Ring, 70A Durometer, Black, 1/2" ID, 5/8" OD, 1/16" Width (Pack of 100)
It makes no noise and I am using it to see how durable it is.
I tried a red silicone one but it did produce a low hum so I went back to the rubber one.
$7.36 for 100 of them is cheap.
I am using these o-rings with my copper platter Momentus TTW turntable. They are very close to the clear ones that were an option with the rim drive set up. I have had a lot of success with them. They are very quiet and last a long time. I see people are using 1/16" wide o-rings. Too thin, they will transfer noise to the platter. These are 1/8" wide which is what you want to use.
206 Polyurethane O-Ring, 70A Durometer, Round, Translucent, 1/2" ID, 3/4" OD, 1/8" Width (Pack of 5) https://www.amazon.com/dp/B0053V30TY/ref=cm_sw_r_cp_apa_i_JtHmCbVXB59NK