Linear vs. Rotary Enc.

Howdy. I have a few questions about encoders. . . the main one being: Is it possible to use linear and rotary encoders interchangeably? If both give the same quadrature feedback. . . is there even a difference besides the obvious mechanical differences (and price)? For that matter, I guess I could ask the same of laser linear encoders. Has anyone tried to use linears on a small machine tool? I would sure like to see some pictures, because it seems like mounting them might be a little tricky.

Thanks,

John

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