A Beogram 4002 DC platter motor recently arrived from Pennsylvania for restoration. It exhibited the typical symptoms of dry bearings: When I powered it up for an initial test it emitted a screeching noise. Definitely, this motor needed a re-lubrication of its bearings! This shows the motor as I received it:
I disassembled it to get the bearings out for oil infusion:
The bearings are the two small donuts on the black pad. I put them under oil and pulled a vacuum:
Immediately, vigorous bubbling started. This indicated that the vacuum extracted the air from the pores in the bearing material, creating space for oil to diffuse back into the bearing. After about 48 hrs the bubbling stopped, indicating that the infusion process had completed. I extracted the bearings:
I put the motor back together. I used my 3D printed tools for installing the top bearing:
After it was put together, I installed it in one of my Beogram 4002s for a RPM stability test with the BeoloverRPM device:
The BeoloverRPM allows logging the RPM for extended periods of time. After about 36 hrs I had this curve:
This is about as good as it gets with Beogram 4002 DC motors. This motor is ready to serve again! Home you go to Pennsylvania!
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