Hi Mike. I have those couplers sitting on my bench. I think they will make a world of difference. Those three cubes above are all different sizes and the two smaller ones were made with no changes between them - that can only mean those couplers are slipping or you are losing steps. I know how loose the slip coupler seemed to me, that's why I ordered the couplers. Swing by and pick them up in the morning. BTW, I printed out a couple knobs for the top of the 5mm threaded rod so that it will be easier to adjust them on the fly. I can't address the software issues, you know that's where I'm weak, but that stuff you are seeing appears hardware related to me.

Dad