Siemens RD 127 Autostop

[Edd]

Hello there!
I am repairing an old and rare Siemens RD 127. It's a combi machine with radio, cd and double cassette. There is a problem with 1 of the cassette players: the autostop constantly activates, even with a tape in the player. It seems that there needs to be a "rocker" with very small notches on the take-up reel. During playback this rocker's notches are pushing on the autostop mechanism, preventing it to be activated. One player has this rocker and is working fine; the other one hasn't: I found a broken bit elsewhere inside the unit.
The million dollar question: where can I get this part? Or anyone suggestions how to fabricate one myself?

 

[BoomboxLover48]

The best option is to make a 3D print of the good one.

With some patience and skill one can fabricate it from hard plastic.
It will be a little hard to find the correct plastic type.
The hardness looks close to Bakelite types.

Looks like you can make one with the same thickness out of Al or brass.

First drill the hole with the same diameter on the substrate and then work on it to get the right shape.
You are halfway there in the making when you drill the right size hole.

 

[Tinman]

3D printing would probably be the easiest if you can find someone that can do it.
I'd probably do what BBL said and fabricate one from something I had on hand.
Another suggestion would be casting a new one with resin.
You can find kits online.

 

[BoomboxLover48]

The resin system Tinman mentioned is basically unsaturated polyester resin in a reactive diluent like styrene that is catalyzed by peroxide as an initiator.
It is a polymer chain reaction initiated with a free radical.
Fillers are added to the mix for strength and hiding/color.

A perfect mold is made in the beginning.

 

[Edd]

Thanks for the replies BoomboxLover48 and Tinman.
As the part is very tiny (center ring piece 0.5mm thick; notches at the end 2mm thick) it's quite delicate to fabricate. And making a mold would not be that easy as well. But I'll start drilling/filing from a piece of aluminium.
By the way; would you know the name for this piece? I called it "rocker" as I saw it constantly moving back and forth around the spindle during operation, while gently pressing on the lever for the autostop.

Best regards!

 

[BoomboxLover48]

If you decide using Al as substrate there will be wear and tear on the parts especially if it is always in action.
That is the only downfall, unless you smoothen it and lube with light grease.

Hard plastic is another choice. If you look around, you will find one.