How do I mange two different motorized focusers?


I have had great success with a stock Robofocus (RF3) on a TMB 130ss with a 3.5 inch Feathertouch focuser. Now I’ve added a homemade Hurst stepper focuser to an APM 80/500. The new motor has a 100:1 reduction rather than the 75:1 reduction for the stock RF3. That’s just one of the major diferences in the specs between the two systems.

The big question is: Can I configure SG-Pro to remember the nominal focus positions for each configuration? That is if I create separate equipment profiles, will the last focus position for each scope and focuser be saved in the respective profile?


SGP will save the locations where you need to focus at setup in the filter dialog. It will do this for each focuser/scope combination. However SGP does not save the CURRENT position of the focuser. This should be stored in the focuser itself. I’m not entirely sure if this is what you’re after.

So in summary:

Yes, SGP can store a close to focus position for each setup. This will vary with temperature but should be a good starting point.

“last focus position” can have different meanings. The current position should be stored on the focuser itself. SGP can store the focus steps but it does not do this automatically. You’d need to set the focus position via the focus panel.


Thank you Jared.

I think what I will do is to rack the focuser in whan I am done to a minimal step count, say 20. Now 20 will mean different in each case. However if SG Pro remeembers the nominal focus position for each scope, I should get close enough when I start up with either scope. I’ll give this a shot. I’ll also look into the RF3 documentation. I remeber seeing something there about using multiple focusers.


Hi Ajay,
I’m curious about your homemade Hurst motor system. Can you post a pic?


Sorry been away for a coupe of days. I’ll post a picture soon.


I communicated with Joel privately, but for any others who are interested, see this thread on Cloudy Nights. My handle on CN is bluedandelion: SGP and focus motor controller