I have designed a 3D printable audio adaptor for the Motorola MC Micro radio. The design cab be downloaded on Thingiverse here :-
The design consists of 3 parts. The first is a grip which wedges between the internals of a 9 pin d-sub plug and the chassis of the radio. This isn’t strictly necessary but does help to avoid the plug vibrating loose. The internals of different plugs might vary so this grip might not always work but the design is made available in Tinkercad to tweak if required. I tried making a plug which would go all the way around but the minimum thickness of plastic most printers use is 0.4mm and there was insufficient space for this to work.
The second is a plate which holds the phono socket while making it easy to access the nut to do it up tight.
Finally there is a simple spacer piece to stop the end of the phono socket touching the d-sub contacts. This part is 20mm long and can simply be scaled to a different height when printing to compensate for a phono socket which has a much greater or shorter required depth.
All designs can be customised in Tinkercad :-
Parts Required :-
1* 9 pin d-sub plug
2* M3 * 30mm screws
1* phono socket
You will need to remove the metal surround from the d-sub plug. You might be able to snip it away using some cutters but I used a dremel type device with a small cutting disc to chop through it at the top and then peeled it back using a pair of pliers. If you do this please wear safety glasses as these small discs can shatter very easily if they catch and the sharp pieces can go flying off at quite a speed.
Step 1 is to push in the d-sub plug and then push in the grip behind it.
Next take the phono socket and solder wires to it and the solder ring. Make sure you do this before fitting as the heat will very easily melt the plastic.
Fit the phono socket. The plastic tends to deform a little under constant pressure so even with a spring washer it might loosen a bit after a while so I would suggest adding some silicone to fix everything in place and help stop the socket from rotating.
Feed the wires through the spacer and solder them onto the d-sub plug onto the speaker contacts.
Screw everything together and fit a phono plug onto the end of the speaker wires and it’s ready to test.