Do physical tape testers exist? aka soft wind/rewind?
 

Sorry for confusing title. After having a couple seized 8mm tapes snap their film inside my camera, I want to start confirming old tapes are not "stuck" in a gentle way before trying to play them. In my mind I want some kind of small plate with adjustable gears and a small crank where I can place an 8mm (or other) tape, and hand crank through to beginning and end to make sure the film is intact. Then if stuck I know I need to bake it or do a repair.

Anything like this exist? If not i'm about to start 3d modeling and prototyping.

You might find this useful for ideas:

https://www.youtube.com/watch?v=8IbpKwGfu74

Hopefully, I've got this right and the link works :wink2:

It's moisture/mold what causes your tapes to stick together and eventually break. The transport mechanism within your camera is actually more gentle on the tapes than those rewinders. Most 8mm tape rewinders are pretty tough on tapes.

Safest way to go is doing it by hand. Or if you're kind of a DIYer, you can build your own device making sure to apply the right amount of force on the tape.

A few hours on a food dehydrator at low temperature wouldn't hurt either.