Cartesian Printer - falling bed.

Firstly I don't want to use a Bowden setup and I thinking of a build plate of 200x200mm.

If I use a light weight printhead assembly do I really need a Nema17 at the end of the axis or can I use the lighter Nema14?

What are your thoughts on an Orbiter and an E3dV6 as the printhead assembly?

Considering most of the weight is in the motors are there any othere ways to get the weight down?

ATB. AAMCLE

Check out rq3's extruder threads in the tech-talk section. He's gotten as low as 42 grams including the motor.

As for the X motor, it can at least be a shorter length NEMA17 than the Y axis. NEMA14 may work, but my guess is that you'd be better off enlarging the Y motor instead. The smaller motor would allow higher Y acceleration without print quality issues due to frame rigidity/vibration, but whether that will result in higher usable print speed depends on whether the NEMA14 can accelerate the printhead at the same rate without missing steps. Ideally you'd want to rig it up with an encoder or other measurement method so you can experimentally find the maximum acceleration rate you can safely use.

If you make the X motor closed loop, then you can push it closer to the limit. You still don't want to be missing steps on a regular basis because it will show up in the print as delayed motion, but with open loop you need a wide safety margin to be sure that the whole print isn't ruined by one missed step.

But really it seems pointless to go to such lengths when you could switch to CoreXY or crossed rail and eliminate the moving motor weight entirely.

We had a hobbyist grade printer at the makerspace several years ago that had a folded sheet metal frame and used NEMA-14 motors for all three axes. It worked fine until the PLA printed parts failed. I can't recall the brand, but the CEO of the company used to stand on top of a printer while it was running to demonstrate the rigidity.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]