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Do any of you have experience with digital protractors?

I'm trying to either harvest the circled component from my gemred digital protractor, but doing so seems near impossible without destroying the board - at least it is for me.

Is there a retail store I can buy what's used here? I already tried buying a generic rotary encoder, but it doesn't seem accurate enough to measure degree movements.
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>>2903340

How big of a form factor can you tolerate? There are a bunch of (probably counterfeit) Omron optical encoders on eBay for cheap, 600PPR in quadrature mode will give you 2400CPR, or 0.15 degree resolution. 2000CPR (8000CPR in quadrature/0.045° resolution) versions aren't much more.

I.E.: https://www.ebay.com/itm/286390488939
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>>2903346
>Form Factor
I'd be building around the encoder so this is really flexible.

Are optical encoders the type typically used for digital protractors? My assumption was some type of capacitive detector or a track with grooves at each degree.

Thank you for the suggestion!
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>>2903522
>Are optical encoders the type typically used for digital protractors?

I don't think so. I believe most of them use the same capacitive encoder PCB thing that digital calipers use (the one you're describing), just in an axial configuration instead of a linear one. That's how mine works, anyway. Such encoders don't use particularly fine tracks. Rather, they use the same trick Vernier calipers use, but do their sensing electronically rather than visually. Either way, they're usually designed and built to be part of the protractor itself, not as a sub-assembly that can easily be re-used.

Another thing that comes to mind is that optical encoders are WAY faster, which is a big deal if you're trying to use them for servo mechanisms or if whatever you're sensing moves quickly. Off the top of my head, the capacitive encoders used in these things can only update at maybe a few hundred Hz to low kHz range, at most. That optical encoder I posted, if it's genuine (or at least if it matches the genuine specs), will go up to 100kHz.Fancy, higher-resolution models will reach into the low MHz range.
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>>2903340
I have this one and it seems easier to disassemble but I haven’t tried. This model is on aliexpress too and probably Amazon
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The one I have has noticable backlash of like half a degree.
Aliexpress has rotary encoders up to 5000 pulses per rotation for ~20 bucks.
Seen 1000 pulses for for 11 bucks including shipping.
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>>2903340
you can buy a hall effect? style encoder thing which just looks like an 8 pin IC and you hold a magnet above it and it tells you the absolute position of the magnet.
e.g.: TLE5501, APS00B, etc etc.



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