@Gabriel_Coleman don’t worry about voltage rating of the motors, the stepper drivers handle that. Typical printer steppers have “rated voltage” around 4-6v but that’s meaningless with microstepping drivers. Worry more about current and RPM (speed). At 19:1 you will want high motor RPM but probably don’t need much motor torque unless your Z stage is huuuuuge. That means you want each motor to get as much drive voltage as possible (to overcome inductance and back-emf) and you should NOT wire them in series.
Separate drivers are always the safest approach, but you may be able to run three motors in parallel off one driver. Worth a shot if you want to try it?
Minimum-pain upgrade route from RAMPS is a RE-ARM.
Z axis is pretty big. Weighs in over 15lb. lol
20x20x1/4in glass, 4 heated beds, gantry, insulated. It doesn’t need to move fast, like the x and y, and that’s fine.
I’ve got the 3 motors in parallel off a big external drive atm, and it works fine. (other than 1.5mm/s max speed). I’m doing full steps on the z axis. The gear reduction provides enough accuracy.
@Gabriel_Coleman I’d use at least half stepping to prevent mechanical resonance. May be able to go faster with half or quarter stepping than full stepping, once you get a 32bit motion controller so step pulse rates are less of an issue.
Note that 8825s are fine (no ripples) with full or half stepping. They only ripple during certain microsteps.
I was thinking the same thing when going to a 32 bit controller. I didn’t think of the mechanical resonances being a problem.
I do have the x and y axis at 16 steps atm.
Duet 2 (WiFi or Eth) does offer an inexpensive external expansion board that lets you wire in the big boy brick drivers. TMC2660 drivers run many (most?) NEMA23 very comfortably in my experience. I put away my Geckos after a while.
But Klipper might be a viable option too.
What’s this external board? Im a fan of the big boy bricks.
@Gabriel_Coleman It’s a board with level shifters that plug into the Duet expansion header. Looks like it allows 5 external drivers. https://www.duet3d.com/DuetAddons/Expansion_Breakout