Modifications For Moonlight Stepper Motor

[Jim Stefancic]

Robert,
I have been using the Focuser Pro2 since it became DIY available. Set up is with a NEMA17 bi-polar stepper and 8825 driver. I am upgrading my scope and focuser to a larger configuration, using a Moonlight CSL focuser with their high precision stepper motor. I do not need to use the Moonlight control software, but expect to continue with the FocuserPro2 as I have it configured. Based on info that you may have, can I easily just connect my DB9 connector to the one on the Moonlight and expect everything to work? I understand that the Moonlight uses uni-polar steppers.

Thank you for any help you can provide,

Jim

[brownrb]

Hi Jim
I believe the moonlite also provides power/gnd via the rs232 pins. Below is text from Moonlite.

We use a high quality Hurst unipolar 12 volt stepper motor with a fairly high reduction gearbox. There is a very small amount of backlash noted with this unit. MoonLite controllers will release idle current to the motor windings when not moving to reduce current consumption and also reduce heat generated by the motor itself; however some controllers like ROBO focuser and others will keep the current draw continuous when not in motion. That can cause the motor to get warm; however it will not damage the motor.

I have attached diagram as shown by Moonlite.

To use these motors - you would need to use a L293D motorshield version which can support both unipolar and bipolar steppers. Be ware most of the designs for myFocuser are bipolar support only.

You would not only have to use the L293D but also wire 12V to RS232 pin 5 as well as the center pin of either M1/M2 port on the L293D.

PLEASE NOTE I HAVE NEVER TRIED THIS. NO RESPONSIBLITY ACCEPTED IN CASE OF DAMAGE TO SELF OR HARDWARE.

Others might have done it, perhaps they can chime in if they have,

Regards
Robert

[Jim Stefancic]

Thank you for the info, Robert. My expectations were that this might be a research project. Not sure that I want to get bogged down in such a task. I guess I'll have to use Moonlight's mini controller.

The Best,
Jim