Hand Ergometer

[irving2008]

I'm surprised it deflects that much, a quick calculation, crudely treating the side as a 6mm deep 'edge' x 6mm thick beam of length 90mm with fixed ends shows a deflection of .01mm per N of load... so deflecting a whole tooth is a 250N load, larger than expected but not impossible I suppose.

The v2 design (100mm long, 12mm deep 'edge' x 8mm thick) is .0013mm per N, so only 0.32mm deflection.

If need be I could add a surround of 8 x 8mm ally angle to constrain the PLA.

edit I was using the Youngs Modulus of PLA as 3450MPa. That article suggests a 50%+ reduction depending on how the filaments are laid down. The max strength requires cross-bonding, preferably at 45deg. So it could be that the forces are much lower, but the relative calculation above still holds.