Back shaft on RS-770/775 or RS-550

[Ether]

This is why I am prodding the OP to provide more detail about what he is trying to accomplish.

[kaliken]

Originally Posted by Ether

This is why I am prodding the OP to provide more detail about what he is trying to accomplish.

It almost seems like he is attempting to direct drive something. I noticed he mentioned that he is looking for a motor that can directly attach to a PG planetary gearbox.

Originally Posted by pavie

(anything compatible with the PG planetary gearboxes from AndyMark)

So if he is indeed directly driving the actuator, he has no where to mount an encoder on the output shaft.

My thoughts, either a pass through encoder (e.g. an US Digital E7P with a pass through cover) or you may need a simple driven shaft with an offset encoder.

Again like mentioned before, if you keep the encoder position you originally are planning... position accuracy will suffer due to gear backlash, slop. It will be tough to compensate for as the true position is technically unobservable with an encoder before the gearbox.