Wally definitely has tricky coordinate transform problem. Look at the concentric circles. They are flat in the back. After scratching my head for a few days, I think I’m on to the problem.
In the two pictures of the arms the small yellow pulley locked yet look closely at the occultation of small hole in the green pulley. Obviously this is two different angles for the same motor position. That would cause problems because the current mapping assume the angle between arms is linearly related to motor position.
@Alan_McNeil Unless I messed up in segmentize (which is entirely possible) I accounted for this. I don’t assume that any given motor rotation correspond to a arm angle. It is possible I got a sign wrong somewhere.
The motor position would translate 1:1 to an angle if the motor was mounted on the arm instead of on the back wall, right? Now there is an offset from the angle between arm and back wall. This angle is controlled by the other arm pair. Tricky 
@Hannes_Lilliefeldt Yes and no. The other arm has to help but the angle can be determined from the X,Y point and the line between the motors (plus knowing the arms angle at home. There is a diagram at https://github.com/NicholasSeward/ConceptFORGE/blob/master/Wally/DOCUMENTATION/INVERSE%20KINEMATICS.png
