Your actual SDS setting is not that relevant it is what ever it is to run at the correct speed, that the setting is not exactly 60Hz is caused by the product the small deviations in all the mechanical interfaces from the motor to the platter. My SDS on one of my tables here in the showroom is set at 59.29.
What belts are you using from the motors to the flywheel ? maybe that is where the culprit is, I use these AS568A-155 Buna N 70 Only use one o ring per motor to the flywheel, then use 4 of the long ones from the flywheel to the platter if that is possible for you. The long ones are not readily available - we make them here from the same type material but thinner and available in 100M spools. If you need some let me know what length and I can make them for you.
Best of luck
Peter
What belts are you using from the motors to the flywheel ? maybe that is where the culprit is, I use these AS568A-155 Buna N 70 Only use one o ring per motor to the flywheel, then use 4 of the long ones from the flywheel to the platter if that is possible for you. The long ones are not readily available - we make them here from the same type material but thinner and available in 100M spools. If you need some let me know what length and I can make them for you.
Best of luck
Peter