Featured Post

Beogram 4002: Restoration of DC Motor Video Published - Check It Out!

By popular request (really, I got quite a few emails about this!...;-), I finally completed my Beogram DC motor restoration video! It demon...

Sunday, May 28, 2017

Beogram 4002 Type 5513: Progress Update

The next restoration steps required removing components from the Beogram chassis since I have to remove the floating chassis assembly to get to tangential arm related work. I also really need to vacuum out all of those disintegrated transport bushings.






















I found little pieces of the original bushings everywhere. Even inside the tonearm cover.





































Here is the Beogram chassis finally clean.




























Next I installed the Beolover 3D printed replacement bushings.
























They fit perfect. It is important when reattaching the floating chassis lock down bolts to make sure the top and bottom locking washer pieces are at the same point of their respective threads. That is so their gap with the bushings are the same on the top and the bottom as the lock down screw is tightened or loosened.

As I continued the restoration work I removed the tangential arm assembly drive screw. You can see there was a lot of excess oil and I discovered the drive pulley didn't have a set screw. It looked like glue was used to secure it.


























After removing the drive components and cleaning off oil I also discovered the drive screw bearing housing had a crack in it. The plastic had been stressed and become brittle.

























Fortunately I have a spare.

























































This picture shows better the drive pulley missing set screw.


























I marked the drive screw mounting bracket position and removed it so I could continue cleaning up oil and replace the drive pulley.





















For the replacement drive pulley I use Nick's aluminum machined pulleys. They work great and look better than the original plastic pulleys. No chance of these metal pulleys cracking either.





















That also solved the missing set screw problem as Nick's pulleys come with their own set screw.

There is still work on the tonearm assembly to do before I can start reassembling any of these drive components. Another task on the list was to change out the fixed arm detector lamp that detects if a vinyl record is present. To do that the end cap of the fixed arm must be pulled out to get to the original lamp.






























This is fairly easy but obviously the tonearm assembly must be removed to do this. I un-soldered and removed the original lamp. Here are the disassembled parts alongside the Beolover replacement part.



































Here is what I think is really nice about this replacement lamp assembly. Its shape is such that it fits into the mounting shell exactly as it needs to in order for the LED to be in proper position for the detector to do its job.



























Another tangential arm component I am replacing is the tracking sensor lamp assembly. All during these tonearm related tasks I was constantly sopping up excess oil which it turned out was just about everywhere in and around the tonearm components.
























I lost track of how many Q-Tips and Kimwipes I used.

Interestingly, when the tonearm assembly board that supplies power to the tracking sensor assembly was unbolted one of the tracking sensor leads popped loose from the solder pad. It must have barely been hanging on for a long time.  You can also spot another small, yellow piece of debris from the transport bushings in the picture. Its amazing that I keep finding them.


I de-soldered the two leads for the original tracking sensor lamp housing and removed it .























Here is the Beolover replacement part installed in place of the original one.






















Note that I haven't soldered the leads of the new sensor lamp assembly yet. I will wait until I get the tangential arm put back together before I solder in the leads on the new lamp assembly housing.

No comments:

Post a Comment

Comments and suggestions are welcome!