ah sorry to not respond to the thread. the reason I am using the crown gear is so that I have to angles of rotation. the video is only showing one, but if I drive the motors in the same direction, then the camera tilts. yay for pan tilt!
My initial plan for it was to make at thing that could play pong with the moon as the ball, but I am not sure if that is going to work. Potentially at low speeds.
Now that I have seen what I am actually getting out of it, I may use it for a kind of physical match move. so I can superimpose videos that have the same pan tilt behavior, but either different content or different locations.
I think redesigning the differential assembly is really the way to go, I will dig, I think I have a worm gear somewhere. barring that, I might have a few more bits I can gear down with.
too bad the keepon isn't cool :( modern robots: loud motors!