Problem with Arch Rotation
The first half of video shows the threaded rod and pvc pipe staying at one end of the supporting arch while the rest of the machine rotates. I was hoping that the pvc pipe would be both rigid and strong enough that it would move with the rest of the machine on the arch, but that clearly isn’t the case.
I was having some difficulty finding a solution to this problem for two reasons, a) I cannot put another servo motor at the pivot point of the arch as that is where someones arm is supposed to go, and b) even if I could figure out a way to get a second servo motor set to rotate the piece around the arch, I don’t have enough ports on the motor shield to support 3 servo motors.
The second half of the video shows a solution to the second part of this problem, as the degree and speed of rotation on either end of the machine will be the same, I can use one PIN to drive two servos.
This only solves one half of the problem, but I have some ideas about how to make a servo motor control the arch. Right now the idea is to place the servo well above the middle of the arch and then use two rods to move the piece, but this idea will probably need to develop more before I start printing.