[lylecheatham]

> Although, I disagree that a screw drive is needed. I use hobbed gearwheel drive on my extruders and rarely is the issue the hobb slipping. Typically, it is the motor stalling instead.

Although that may be the problem on your printer, it's simple to fix because one can always add a larger motor. The problem that they solved is that eventually, a stronger motor won't cut it because the hobbed gear will slip, and that's what this paper is all about. Optimizing the motor is done by just upscaling it, but optimizing the drive is what made them to move away from the existing hobbed gear setup.

> They could go faster if they used a 32 bit controller like a smoothieboard or duet instead of the 8bit "arduino based" controllers. {Not saying RAMBO is a bad board, they are known to be very reliable for OEMs}

I would actually predict a minimal increase in speed. 32-bit controllers don't make for inherently fast printers, they allow for it if utilized properly. What you'll find though is that Marlin and Smoothie both use the GRBL planner under the hood, and generate very similar output. The only major difference I noticed in the output between the two is that Smoothie generates smoother (hence the name) step waveforms.

I guess you can also generate steps at a higher frequency with smoothie, but you should be careful equating higher step frequencies with higher speeds, when most of the time people are running with microstepping settings. Higher frequency allows you to get more dynamic range between speed and precision, but that's not really what the paper was about.