CGE Pro DIY OnStep Conversion Kit


This kit is for those people that want to build their own OnStep computer.  It is everything you need to install Nema17 stepper motors directly onto your CGE Pro mount. No modifications to your mount! Just take your OE motors and motor boxes off and bolt these parts on.


6 in stock



This kit is for those people that want to build their own OnStep computer.  This kit comes with everything you need to convert the CGE Pro mechanically to stepper motors.  The wiring hole on these motor boxes are made to accept the CGE Pro connector that is on the OE motor box.

  1. Two – Nema17 2amp 200steps per revolution motors
  2. Two – Machined Aluminum motor mount adapters
  3. Two – 3D Printed PETG motor boxes
  4. Two – 60T GT2 gears
  5. Two – 12T GT2 gears
  6. Two – 200mm GT2 belts
  7. All the stainless hardware you need to attached to the CGE Pro

I have not found a way to leave the CGE Pro motor mount brackets on the mount to put the 60T gear on the end of the worm gear.  So I will include the Celestron instructions on Adjusting CGE Pro Mount Motor Brackets .  I will also make a video on the topic.  It is not difficult it is just a good confidence booster to see someone else go through the process.

Currently I am using my CGE Pro with a Wemos/CNC OnStep computer. The way I have mine setup is with the following:
LV8729 Drivers at 16 microsteps

Here is the Config.h file that i use with this combination.
Also the OnStep excel sheet used to calculate the steps per degree.

GR1 is 5 (5:1 gear reduction for 12T – 60T gears)
GR2 is 255 (there are 255 teeth on the RA and DEC CGE Pro worm gear)

I am working with a partner company developing a custom OnStep computer but it is still months away it appears.  When we get this computer running I will incorporate the CGE Pro PEC sensor and Home/Limit Switch Sensors.  The Wemos/CNC computer does not have enough inputs to do all of these.

Video of my first successful movements.

Additional information

Weight 4 lbs
Dimensions 9 × 9 × 6 in


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