Hi,
I was thinking about hacking the gear from your gearmotor: pololu.com/catalog/product/1576 to use with a stepper motor. Can you tell me the diameter of the motor shaft or the diameter of the hole in the sun gear? I I didn’t see that info in the specs.
Hello.
I don’t have the shaft size off the top of my head, but I expect it to be in the 2-3mm range, which is less than most steppers. Also, the gear is very unlikely to be removable with normal tools and effort. Finally, these are not planetary gearboxes. Do you still want someone to look up that shaft size?
- Jan
You sunk my battleship! 
I had anticipated some of the things you mentioned, I thought maybe I could heat the gear (assuming it is metal) and make some sort of small hub puller device like a water pump pully puller. I was hoping to be surprised and the motor shaft was the same diameter as the output 4mm and that would actually fit my stepper, since it is smaller I would need to make a coupler to couple it to the stepper shaft or maybe grind down the stepper shaft. Yes, too much work and I was looking for a planetary gear anyway. Thanks anyway.
