Beogram 4002: DC Platter Motor Restoration

A DC platter motor of a Beogram 4002 arrived from North Carolina for restoration. This shows the motor as received:

I disassembled the motor to get to the bearings for oil infusion:

The bearings are the two small donuts on the black pad. I immersed them in motor oil and pulled a vacuum. Immediately, strong bubbling started, indicating that air was drawn from the bearings to make room for fresh oil interdiffusion:

After about 48 hrs the bubbling stopped indicating that the oil was replenished in the porous bearing material. I reassembled the motor and installed a new pulley:

These pulleys are perfect replicas of the original ones. The shows one in comparison to an original type:

There is virtually no difference, except that the new one looks new!...;-). If you wanted one, I will be happy to put you in touch with the B&O enthusiast in Vienna who designed them. Just send me an email or use the contact form.

After assembling the motor, I installed it in one of my Beogram 4002s for an RPM stability test with the BeoloverRPM device.

The BeoloverRPM allows logging the RPM for long periods of time, which is very useful for detecting intermittent RPM stability issues. This is the curve I measured after about 24 hrs:

This is as good as it gets with the Beogram DC motors! This motor is back in business. Time to send it back to North Carolina!