Beogram 4004 (5526): When Disaster Strikes - Ripped Off Leaf Spring Adjustment Bolt

I made good progress with the restoration of the Beogram 4004 (Type 5526) that I recently received from a customer in California. Until I came to the part where I adjust the floating chassis and align the platter etc...what is usually a tedious, but fairly straight forward process quickly turned sour with this unit, giving me fodder for another post in my 'when disaster strikes' series!...;-):

What happened was that when I tried to adjust the height of the three leaf springs to get the floating chassis level, one of the adjustment bolts ripped off. I thought it was turning a bit difficult, but in this case it turned out that one of the previous owners had epoxied the nuts to the threaded sections of these bolts. Since I usually use a ratchet with a nut to turn these screws, I did not see that I was actually twisting the bolt and not just turning the nut!

This shows the assembly before the disaster struck (luckily I took a picture after straightening out the grossly bent alignment pins for the aluminum cover plates). The bolt in question is behind the pin to the right: 

This is the section that came off:

After removing the leaf spring it looked like this. The bolt had separated at a level flush with the threaded hole in the enclosure bottom. Pretty Beounlovely!!:

At least, after heating the bolt with my solder station blower I was able to get the nut separated from the bolt fragment:

The next step was dealing with the broken off bolt fragment that sat flush in its threads. Such twisted off bolts are dreaded by anyone how deals with mechanical things! It is usually a bit of a mess to deal with such bolts. Since I only have a mini drill press for delicate tasks, I opted for drilling the M4 bolt out in three steps. First I made a mark with a center punch as centered as possible on the bolt surface. Then I used a 2 mm drill to hollow out the bolt. I used some oil to prevent the drill from getting stuck:

The next step was re-drilling the hole with a 3 mm drill:

And then I finally went in with a 4mm bit. This cleaned out all the remnants of the bolt:

Then I Installed a M4-45mm stainless steel flat head bolt with a nut and a washer:

This was possible since the mounting posts for these adjustment bolts are hollowed out and accessible from the bottom of the enclosure. The flat head of the bolt fit perfectly and flush into the hollow:

And this is how it looked with the spring installed again:

Looks like it never happened! Beolovely!

Beogram 4002 (5513): Repair of a Missing Leaf Spring on a Plate Lock

When I set out to do the sub-chassis, platter and tone arm lowering adjustments on the Beogram 4002 (5513) that I am currently rebuilding I realized that the larger aluminum plate was not seating properly with the plinth pushed back. If that happens it is impossible to properly adjust the platter to be flush with the plate.

The plate was wiggling up and down in the back left corner where one of the locks that are supposed to pull the plate down onto the frame when the plinth is moved back did not do its job. The locks accomplish the pull-down with a leaf spring that is attached to the bottom of the lock plate. This shows the right-back lock that still has the leaf spring attached.

I thought a bit about how to fix this, and I know that many Beograms either never had the springs or they fell off at some point and were discarded. In these cases often a tech bent the lock plate to act as a makeshift spring itself. Now in this case since the other three lock plates still had their springs attached, I did not want to bend just one of them. Somehow this did not feel Beoloving enough. So I came up with this fix:

A 3D printed wedge that fits to the bottom of the lock plate:

I glued it to the bottom of the plate using double sided tape. I always try to do things in a reversible way in case someone comes up with a better fix in the future and wants to remove my fix. 

When I put the aluminum plate in and pushed the plinth back, this wedge very satisfyingly pulled the plate down to where it should sit. All good now with this plate lock! No detail to small for my attention! This is Beolove! On to the platter and sub-chassis adjustment.