Well, I’ve been looking around at torque sensors and found some interesting information. For one though, they are NOT cheap. Keep in mind that these are higher sensitivity sensors but it doesn’t seem to have an overwhelming bearing on the overall price. for example.
Optical, high sensitivity sensor, ~$6000
Magneto-elastic sensor, ~$2000
Strain gage based, ~$4300
While this is expected, it’s still quite a cost on a per-unit basis. interesting.
Another little tid-bit I picked up is this.
Magneto-Elastic sensor document
Anyways, I’ll keep looking for a cheaper unit, though, I doubt I’ll find one cheaper than the unit I developed. Perhaps I’ll machine a small enclosure with precision bearings and develop a more robust and practical design. I have some conductive graphite for the brushes in order to reduce noise and the brushes could be replaceable. Might try it.