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Beogram Commander Remote Control: Maybe This is the Final Version!..;-)

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...

Monday, November 23, 2015

MMC20 Cartridge Mount Replacement: Third Design Iteration

This is a follow-up to my initial posts about the design of a MMC20 cartridge mount replacement. The first design iteration is discussed here and the second one here. The result of the second iteration was pretty close as in that I was able to stick a cartridge on it and that the base fit into the arm tube of a Beogram 400x. The issues with V2 were that the angle at which the cartridge mounted was about 4 degree off and that the cartridge was a bit loose. Furthermore, the nylon based print was too flexible. 

Version 3 shown here uses a different, stiffer material and I changed the geometry a bit to ensure proper mounting angle and a tighter cartridge fit. Here are a few impressions:

The mount now fits with a decent press fit into the arm tube (I did have to sand it slightly - a concession to the still imperfect printing tolerances at Shapeways). It also looks fairly original, although the material is a bit rough in difference to the original injection molded plastic:

The good thing is that the tab is invisible once the cartridge is mounted. Here is a picture of the fit:

Quite prefect now, I would say...After I stuck the cartridge on I measured the coil resistances while wiggling the mount a bit. It seems the contacts between mount and cartridge are now stable!
To get this ready for prime time, however, I still need to learn to gold-plate the Cu strips. Another point is to find a more perfect way for glueing the contacts PCB. Beolove springs from continuous improvement! But I am fairly positive now that this design is getting pretty close for some in-situ testing.



1 comment:

Comments and suggestions are welcome!