Okay that went fast. I figured it would take a day or two to get some eyes on this. And a day or two per topic. Let’s try something more complicated this time.
Z Axis drive system
I think we all agree on CoreXY, right? Three Z steppers so we can physically adjust the level before mesh leveling? I think those are givens right?!
Belted Z (with drop protection) or Leadscrews?
I chose belt because is less expensive (smaller BOM belts and idlers that are already needed elsewhere. Belts let the rail do the guiding of the motion with no outside influence from a bent leadscrew (look at HevORTs solution to this).
The downside is the drop with heavy beds. A 200x200 thin mk2 bed with a wood carrier plate does not drop very fast. So that means an added part is needed.
- We can gear down the Z belts, that means an extra belt loop and gear set/bearing.
- We can use a constant tension spring, ~$7 each, would need to be tuned to the weight of each machine. Something like this https://amzn.to/41WhWAh
- Electronic brake. Mike M had an idea that I already ordered to try. These exist, Mini 2 Z Brake Board Kit | Lulzbot 3D printers they cost a lot. Mike’s idea was try this Amazon.com Best bang for the buck, short one stepper coil and the stepper will hold (or possibly drop extremely slowly) even with a very heavy bed.
Let’s get to the frame after we have some of the basics knocked out. I think that is going to take two rounds of choices.