176 euros for the motor without the controller for a $20 stepper motor and a $10 gear and belt. That is an expensive bracket but you can see the design, although bulky , would work.
The two essential parts of the JMI / celestron focusser apart from the motor is an aluminium and rubber ring friction fit collet over the focusser shaft (or plastic knob adaptor ) and a plastic tube with a plastic grub screw on the focusser housing to mount the whole assembly.
I suspect you could have these made in aluminium tube to fit any focusser shaft or knob for older SCT or indeed a feather touch shaft.
The really useful part of this design is that they can be taken off and on easily and the focusser shaft is still available for quick manual use.
Recent SCT I think do not have a projecting tubular focusser housing to accept the plastic motor tube and thumb screw ( thus the new design) but I suppose adaptor plates are not too complicated either.
Quote:
Originally Posted by The_bluester
I wondered about one of the Celestron units, but I replaced the focusser on the C925 with a Feathertouch two speed years ago and have not got the original any more.
I wondered about one of these but again I would need a standard focusser, or custom parts to fit it to the Feathertouch
https://www.astroshop.eu/motors-cont...-c9-25/p,57049
None of the options (Apart from something on the visual back, which I have not got space for in the imaging train) would eliminate image shift while focussing but without physically touching the focus knob it would probably be reduced a fair bit. |