@Jon: I am not sure what is meant by a parallelogram linkage. Are you talking about something like THOR Simpson? It would only work if you do that to two arms. However, I would advise you to figure out what the weak link is and beef it up. (Mathematically, your position should be constrained so it is just a matter of sizing all the components to get acceptable rigidity.)
I know this would be annoying to do but the the worm needs to be registered with a pair of bearings and some thread clamps.
I would also consider splitting the shoulder gear and adding a torsion print as a backlash removal attempt.
Note: My apologies if you have already done some of these things.
Good luck!
I know this would be annoying to do but the the worm needs to be registered with a pair of bearings and some thread clamps.
I would also consider splitting the shoulder gear and adding a torsion print as a backlash removal attempt.
Note: My apologies if you have already done some of these things.
Good luck!