I always fancied giving one of these a go, having used the real thing at Sony and Panasonic and failing to bring them home when I left, forgetting that I paid for them in the first place, there’s been a few instances where I’ve needed to check the take-up tension on a tape deck.
So, armed with a jar of various springs and an old cassette I set about to make my own.
Obviously it’s not going to be a fully rotational unit, however, it will measure perfectly fine for a few seconds before the auto stop cuts in.
Here are the results.
Quite pleased with the result and it’s calibrated to a Tentelometer, so it’s quite accurate.