Fitting motor focuser to Skywatcher dual-speed Crayford?

[MartinFransson]

Hi!

I have a Skywatcher motor focuser (the same type that is sold under a whole lot of names):

Now, all instructions I can find on Youtube etc show the attachment of this motor focus to refractors with a single speed Crayford. Could anyone help how to mount this to my scope? I´m not very good with these things 🤣

My focuser is the Skywatcher Dual-Speed Crayford 2-inch Focuser and the motor focus I´ve got is this one:

https://www.astroshop.eu/motors-controls/skywatcher-auto-focus-system-for-telescopes/p,11469

Would that motor unit also be possible to control via USB from a computer? If so, how?

[johninderby]

It’s pretty straight forward. This Youtube vid will give you the idea.

You will need a usb motor controler to control the focuser from your PC as the focuser is just a dc motor and the stock control box just alters the voltage.

https://www.firstlightoptics.com/astronomy-cables-leads-accessories/hitecastro-dc-focus-controller.html

 

Edited September 24, 2019 by johninderby

[MartinFransson]

3 hours ago, johninderby said:

It’s pretty straight forward. This Youtube vid will give you the idea.

You will need a usb motor controler to control the focuser from your PC as the focuser is just a dc motor and the stock control box just alters the voltage.

https://www.firstlightoptics.com/astronomy-cables-leads-accessories/hitecastro-dc-focus-controller.html

 

Hmm, I actually had watched that video before but I thought there was a difference since he had an ED80 and I have a 150-PDS Newtonian. I also got confused by the bracket things not seeming to fit my focuser since they were curved. Now I see that his is as well and it doesn´t seem to matter.

Might give this a go tomorrow

Thanks for the help!

[MartinFransson]

@johninderby do you know if mounting the DC-motor to the single speed knob (as is done in the video) gives enough resolution for really fine tuning focus? In the video I think the focuser seems to move rather fast even when he´s got it on the slow setting.

[johninderby]

I found that to get really slow focuser movement you need the pc control with a usb control box. The Hitec one has regular speed control or simulated stepper control for super slow movement.

The standard control box that comes with the motor isn’t that slow even on the slow setting.

Edited September 25, 2019 by johninderby

[MartinFransson]

1 minute ago, johninderby said:

I found that to get really slow focuser movement you need the pc control with a usb control box. The Hitec one has regular speed control or simulated stepper control for super slow movement.

The standard control box that comes with the motor isn’t that slow even on the slow setting.

Ah, but with a controller it works? My plan was to get a Hitec (or similar) anyway since the whole point was to be able to adjust focus from indoors. Enough of running out in my pyjamas in the middle of the night to refocus

[tooth_dr]

I have these fitted to my ED80s and find they offer good movement range. I rarely have my on the slowest setting either and it works really well. I use the hand controller.