Make your own sanding cartridge

If you have an 8-track player that is struggling with a bit of "uneven play" on several cassettes that usually play fine in other players, the problem could be a TOO polished "capstan". This can happen after many years of use where pinch rollers and tapes have polished the capstan so smooth that it no longer gets enough grip to pull the tape forward properly.

The permanent and best solution to the problem is to have the capstan sandblasted, but this is a complicated process and I am not sure how easy it is to find competent personnel in this area in this country. Therefore, here is a VERY GOOD "quick fix" to this problem, namely to transform an old cassette into a kind of "sanding cassette".

The sanding cartridge looks like this. It has a roller with sandpaper glued on it that sands the surface of the capstan in the player so that it has a better ability to pull the tape forward again.

The procedure is simple:
Take apart an old cassette that you can sacrifice. Remove the tape, pressure pad and take out the pinch roller. Use a cassette with rubber rollers, plastic ones will rarely work. Cut a fairly thick strip of 240 grit sandpaper and attach it to the pinch roller with a thin double-sided tape. Make sure to get the sandpaper joint as tight as possible but without overlapping. Play this cassette in the player for a few minutes, but make sure the roller rotates the whole time! The result will be a duller capstan that will have no problem pulling the tape forward. Finally, clean the capstan in the player with alcohol.

If you use the player often, the problem may return, so you may have to repeat the process after a while. It may therefore be a good idea to save the "grinding cassette" for later use 🙂

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