Quote:
Originally Posted by IKE
You mention needing 25" of travel. What level of precision and accuracy are you expecting, wanting? {also, what response time?} Beside the key or badge retractor, you may want to look into a Yo-Yo ball.
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Not necessarily professional quality. I'm assuming in the 0.1"-0.5" resolution, not 0.05" or better. I'd prefer something in the 4-8 steps/inch (0.125"-0.25"/step) ballpark. Whatever is SIMPLY achievable.
Linearity is not needed, but REPEATABILITY is vital. Out and back to the same point should yield VERY close to the same value, whatever it may be. This allows for calibration tables to deal with the linearity challenge.
Response time? Fairly slow. The application is pneumatic cylinder extension monitoring, so as long as the data keeps up with the cylinder motion we're fine. Since we're limited to 24" strokes, a 25" max cord is reasonable.
Quote:
Originally Posted by Qbranch
Use a retractable keyring holder and trim pot. Just super glue the trim pot's screw to the shaft of the keyring holder. {...}
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We tried that at one point, but had both fab and repeatability challenges with it, because the reel used allowed for overwrapping.
I do like the PVC threaded end suggestion! I need to think on (or tinker with) that one.
Any other ideas, or working models? BTW... IF there's anyone that has some images of a working model, I'd LOVE to see them posted in the CD-Media area!
Thanks!
- Keith