allright. To me it really was a problem with the lower right arm which made me think it was a hardware issue. But I double checked the arms and swapped them around. Having said that, could it be something on the controller board? I also noticed that pressing the z-axis up button sometimes resulted in the bottom right belt unspooling. Just relaying my user experience. Maybe it helps. For now I’ll wait for your input on how to proceed. Let me know it there is anything I can do in terms of user testing .