Beogram 4002 (5503): Adjustment of Sub-Chassis, Platter and Tonearm Weight and Limits

The final step of the restoration of the mechanical systems of the Beogram 4002 (5503) that I am currently rebuilding was to balance the sub-chassis, adjust the platter height and bring the tonearm up to specifications. The sub-chassis needs to be adjusted that it sits centered between the opened transport lock clamps for maximum range of free motion. Then the platter height and vertical alignment needs to be adjusted that it sits flush with the aluminum covers of the Beogram. Once this is done, the arm lowering limit can be set and the tracking weight can be calibrated to match the scale on the weight adjustment dial on the side of the arm weight housing.

Here is a picture of the platter after all the adjustments. It sits centered in and flush with the opening in the surrounding aluminum plate:

Then the arm lowering was adjusted that the stylus just misses the lower parts of the ribs on the platter. This is an important adjustment since it will save the cartridge if the arm is accidentally lowered without a record present in case of a sensor malfunction (the control system is not setup to detect a photosensor failure):

Then I replaced the flimsy circlip that holds the counterweight adjustment screw in place with a nut. This ensures that the tracking force calibration is still correct after shipping the unit. This shows the original setup:

And with the M3 nut installed:

Then I balanced the arm:

In case you would like to do these adjustments on your Beogram, there are two videos on my YouTube channel that show how to adjust the platter bearing and the subchassis (in a Beogram 4000, but the process is very similar in the 4002). There is also a video about the tracking force calibration process, and there is another video on my youTube channel that shows how to adjust the lowering limits. 

On to rebuilding the electronic parts of this Beogram!