Dabrush OP t1_itpygwq wrote on October 25, 2022 at 1:34 PM

Reply to comment by HalcyonKnights in How can I measure the length of string passing through something? by Dabrush

This does sound like a relatively safe idea, now I'd just have to find a good way to count the rotations of that barrel, or ideally just give out the total spooled length directly.

Angdrambor t1_itq6j57 wrote on October 25, 2022 at 2:32 PM

Just buy a Measuring Wheel and skip building your own mechanisms. It's designed to be rolled over the ground for long distances, but there's no reason you can't use it to measure thread rolling over the wheel.

If your string keeps falling off the wheel, you can glue cardboard guides to keep it in line.

HalcyonKnights t1_itpzrlf wrote on October 25, 2022 at 1:44 PM

I would not try to reinvent that Wheel (unless you want to spend more time and money on the learning experience).

Mechanical (Rotating Shaft): https://www.amazon.com/Mechanical-Counter-0-999999-Resettable-Accurately/dp/B0975Y79RF/

Mechanical (Paddle Whack method): https://www.amazon.com/KTRIO-Counter-Handheld-Clicker-Mechanical/dp/B075QFK6DG/

Electronic: https://www.amazon.com/DIGITEN-Digital-0-99999-Proximity-Magnetic/dp/B01DNLRAUA

Gubguls t1_itr3j2h wrote on October 25, 2022 at 6:07 PM

I don’t think that’s the type of sensor he needs. Something like the rotary encoder as was suggested.

SuperbLlamas t1_itqjqeq wrote on October 25, 2022 at 3:59 PM

Rotary encoder is how I’ve done something similar in the past.