One more pic, showin how much material was trimmed from the original drive sprockets. 11.62mm, according to the cheap harbor freight digital caliper I've got. I trimmed it with a 24TPI hobby saw. It wouldn't fit into the miter box I've got, so I free handed it.
unnamed (2) by
Anthony Kalnoski, on Flickr
I used a hole ream bit to enlarge the center hole of these 25tooth servo hubs. i enlarged them just enough that they would pass over the hole. Once they were large enough, I used
RED locktite to insert 2 screws in them. I placed the screws into the sprocket, & attached the hub to the sprocket with epoxy.
These sprockets should be better centered than the previous attempt. After the epoxy had dried, i used a 15/64 drill bit to make the hole of the drive sprocket large enough that a 3mm button head screw could pass through the center. I
DIDN'T have a 6mm drill bit, so I used what I had that would do the job.
I had to forego power tools for this, as this made the walls really thin! I hand drilled them, then fitted the servo hub back onto it.
HOPEFULLY once the other parts arrive, & I can put ti together, it'll function as intended!