The Crayford telescope focuser design – developed in 1971 by John Wall and named after the Crayford Manor House astronomical society – has a number of important advantages over rack-and pinion and can be home built out of wood by almost anybody with a bit of patience and the right tools at hand.
I designed this focuser specifically to carry the weight of a Nikon D7100 camera on prime focus (± 800 gr), which is considerably heavier than even the largest eyepieces. So far, it is holding up admirably. more »