telefunken: TFK 33GL zamak loudspeaker base replacement

Dear Gentleman

 

I want to share some experience restoring a Telefunken 33GL radio.

The base for the driver of the speaker is made of a material similar to zamak.

As I received the set this base was in very bad conditions, unusable.

This is a common problem with zamak, lack of stability of the alloy.

 

Fortunately the part was good enough to do some reverse engineering.

With this information the attached drawing of the part was done.

The idea was to do the part in a CNC router. But the workshops with this tool refused to do small batches. The cad drawing is made in layers for use with these tools.

I don´t know how to upload a dwg file, but is available by mail.

 

Using this drawing I did a wooden mold, and then transfer the shape using silicone rubber.

The final part is made of epoxy resin. The part on the left is better finished because vacuum was applied after pouring the resin.

The machinability of the epoxy is very good using steel tools.

I did only two parts, the ones on the photo.

 

I will be very glad to answer questions on this subject.

 

Jose

 

Attachments:

• loudspeaker base (32 KB)
• base mold (41 KB)
• driver assy. (23 KB)

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