This is a follow up to my recent post about the redesigned Beogram Commander remote control board, which now works in both (DC-motor) Beogr...
Tuesday, March 20, 2018
Beogram 4000: Glueing a Delaminated Platter Back Together and Installation of New Cabined Guidance Washers
The Beogram 4000 that I am restoring right now unfortunately had suffered some transport damage due to the inept packaging job of the ebay seller. Since he did not take out the platter, it bounced around and in the process delaminated into two parts. This shows the bottom and top parts of the platter:
It is interesting to have a peek inside the platter assembly. It appears that the lower part of each platter, which provides the main weight of the assembly, was individually balanced, similar to what is done with car wheels after putting on tires. They did that by drilling out small portions of the materials on the too heavy side of the platter (you can see the red pen mark from the balancing process next to the drill pattern):
It is also clear from the markings on each of the ribs of the lower platter that both parts were glued together. Inspired by this finding I used a slow curing epoxy glue, which I applied next to the original glue spots:
Then I placed the top part off the platter and aligned it as good as I could. A 4002 platter served as weight to secure both halves in place while the epoxy cursed for 24 hrs:
In the meantime, I replaced the old cracked cabinet guidance washers with new 3D printed ones. This shows the original center washer at the front of the enclosure:
This one is a strange design aspect of the 4000...it seems to be a flat Teflon washer that has no guiding feature. This one is best replaced with a 3D guidance washer printed in black, since white ones are visible from the front through the crack between the cabinet and the aluminum panels:
This shows the complete set of five 3D printed guidance washers:
They are available through the Beolover Shapeways store (see link under 'pages' on the right).