I have bought this poorly treated radio at the local flea-market. With a very dirty bottom side, missing tuning knob and a crack case, it looked like it was treated badly by the previous owner.
Having a closer look at the poor radio, the battery compartment was spotless – thus, the outside dirt was just that, and not battery leakage. The white grime went away easily and broke down in small clumps – indicating a sort of a sandy construction material …
There was also a crack behind the missing tuning knob, as if the radio took a fall onto the knob:
Since the white grime was rather thick, I decided to open up the radio to see if there’s more inside.
Like any other radio of this type, there are two long screws on lower back of the case, with a third smaller screw hiding behind inside battery compartment.
Having a closer look, the radio was full of dust. Do not sneeze!
A soft brush was all that was needed to de-dust the radio – and a little elbow-grease to push back the cracked plastic. I didn’t glue it, since glue will leave residue and the plastic seemed tight enough to just hold.
Using the tuning knob from the other Radio International as inspiration, designing and 3D printing a similar button was easy:
There was a problem though, tuning the radio was very hard, the tuning knob was very stiff. Only 1 pulley was turning, the remaining 3 were stuck. Having a closer look, something drew my attention.
Metal shards were stuck between the pulleys and the plastic case. In one case (first photo), the melted end of the shaft was deformed because of the shard – most likely it got in when the radio was assembled.
Prying the shards out was very easy and this freed both affected pulleys. The lack of attention during assembly + the fact that thread seems a tad short putting a LOT of pressure on the plastic shaft of the pulleys indicates this radio wasn’t built to last.
The last remaining pulley to be stuck is a lost case. It is just pressed against the case of the radio. This thing won’t move. Not sure if it is intended – as in to artificially increase the tuning resistance – or is just one more case of not caring.
Having it cleaned as best as I could, I put the radio together and tested it. It works fine. Attention, loud volume:
Few more shots:
My 3D printer doesn’t have the resolution to print the small groves on the tuning knob. I will improve the design once I get into resin printing – for now, it is rather slippery to grab. But still works well.