I would lubricate the bearings yearly. Around every 12 months I would sense speed instability. Bearing lube fixed it immediately. Motor oil for the motor is probably needed less frequently.
I agree with the above - ALWAYS use VPI bearing grease and motor oil. It's cheap relative to the cost of the investment in your turntable.
I agree with the above - ALWAYS use VPI bearing grease and motor oil. It's cheap relative to the cost of the investment in your turntable.