[darbikrash]

Originally Posted by Engine-Ear

RE: Shutter Wheel pic - is there a balance issue? Seems like a meaningful fraction of the disc is cut away. Thoughts?

It is supported by a Oilite bushing fairly high up the shaft, so the bending moment is quite short. Ideally, there would be perfect balance of mass, but with a stiff supporting shaft it should be OK.

The best check is to place a hand on the outer housing when it's running to see if it has any excessive vibrations. If it turns out to be an issue I can relieve material (remove mass) on the opposite side of the slot from the bottom face so as to not interrupt the sensor.