What about slop? What if the problem that you are seeing is similar to the traxxas joints where the effector will still have small movement on the joints. Magnetic joints seem to suffer from the same occurrence.
You may try adding springs to tie the arms together. Other people use rubber ands or print out connectors that clip onto the rods. [dustsreprap.blogspot.com]
You may try adding springs to tie the arms together. Other people use rubber ands or print out connectors that clip onto the rods. [dustsreprap.blogspot.com]