Originally Posted by
MechanoMan
Well yeah but that's a NEMA34. I would need to use a different mount and drive and power supply.
I have come to appreciate the need for a NEMA34 drive on R&P. Not because NEMA23 isn't powerful enough- NEMA23 is plenty strong enough for torque. But tensioning the XL timing belt in the reduction stage causes too much load on the NEMA23's 1/4" shaft. There's only like one or two oddball NEMA23 motors with 3/8" output shafts. Not a thing on the ballscrew though.
If I was going NEMA34, of course there's a whole page of NEMA34 options on AutomationTechnologiesInc. I'd think the Leadshine drive would be the way to go, too. Well, I see an 80v/7A drive Leadshine DSP drive, and there's 1200 oz-in steppers that pair with that. I know they have much greater rotor inertia that loads down the acceleration profile, but I haven't tried to figure out how significant that is vs the Z-axis weight.
I do like the 3D work and want to optimize the machine for that. Mach3 is turning out to be a limiting factor, though. For reasons no one seems to be able to explain, it's taking substantially longer than it should. The total runtime doesn't scale 1:1 when you double the speed & acceleration- it does take less runtime, but the runtime doesn't halve itself. And comparing it to LinuxCNC runtime, LinuxCNC is about 20% faster and actually does speed up proportionately when you increase the axis capabilities. I don't know why this is, but it's a Mach3 thing that limits 3D work.