[Encoder] off-shaft encoder or hollow shaft encoder


I’m looking for an off shaft encoder or hollow shaft encoder, is there anything you can suggest?

Maybe from RLS?

AksIM-2™ Off-Axis Rotary Absolute Magnetic Encoder Module

Or is there any other encoder that you recommend with hollow shaft?

Best regards


Welcome to the forum.

Please check this thread, it may have the answers you want, though they may not be the answers you need.


Thanks, looking forward to spend time here!

I will use search button more often :slight_smile:

Ps; can you recommend any hollow shaft encoder incase you used one before with simplefoc? They did not speak about it.


Hey @rndbit ,

AMT optical encoder devices like the AMT103 have been used with SimpleFOC successfully… If your design can accommodate their size this type will be easier to use than the magnetic sensors mounted off-axis.


Thank you for your reply, the AMT103 would not work when we need slipring cables to pass.
Do you have any recommendation for magnetic sensors that is mounted off-axis that works with simplefoc?

Best regards

One note, does it support ATM33 encoder? it seems to have large hole to be able to put wires.


Yes, I think it would be supported… any encoder with quadrature or A/B outputs should be supported via the Encoder class.

I guess maybe you meant something like this:
That’s an encoder with a true hollow shaft, designed for passing cables through…

That type of encoder should work too, it has A/B/Z outputs and should be supported by the encoder class… kind of expensive though!


That is great! Thanks for tip!

Maybe this is a cheaper option:
USA-DIGITAL E3-8192 Encoder

They have with 20mm hollow shaft, looks like it would work as well with simplefoc. What do you think?

Used where it may be difficult to slip a full ring encoder around a shaft. Allows removal and reinstall of shaft without removal of encoder.

These type of things make me wonder if it would be possible to repurpose an old hard drive or optical drive as a very high resolution absolute encoder. Write a specific pattern (grey code?) to a platter or CD and let the read head do its thing detecting the pattern. Disassembly and coupling to shaft without destruction would be the real trick.

I know the 3 phases of a hard drive motor can provide a useful encoderlike signal for something like a DJ scratch deck.

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