Steve did the math, and apparently the "optimal" rotation in RPM on 4"
wheels for 13" cube is about 4:1. -1/-0.25 works well. But -0.5/-0.25
works almost just as well. But turning down the maximum RPM actually works
better for the initial "grabbing" the cube.
Steve did the math, and apparently the "optimal" rotation in RPM on 4" wheels for 13" cube is about 4:1. -1/-0.25 works well. But -0.5/-0.25 works almost just as well. But turning down the maximum RPM actually works better for the initial "grabbing" the cube.