Belted Z axis

[TheOnlyMann]

Since the printer involves more Z axis movement than on traditional 3d printers, it might be better to incorporate a belted Z axis onto the printer on hand to make nonplanar printing more accruate in a way.

Video linked
Anyways the point I want to make is that if we switch the shaft attachment with belt we could move the motor down to the bottom which might prove better for the printer jiggling.
There are Voron belted Z mods that already exist and could be used on the current design to replace the shaft with belts.
While I want to explore this further Im quite dumb when coming into this, so had to made it into a discussion.
Otherwise, we can't use the motors directly since when the motor is turned off, unless the gear ratio is big enough its gonna plummet.
Hope this discussion brings something else to the table.

[ehegenberger]

I've been looking into this myself for the past few months, and from what I've been reading it seems to be more a fun and different way to do the same thing rather than a dramatic improvement in print quality. The belt is lighter, than the lead screw, but you're incorporating still more moving parts and in my mind the potential for more slop and play.
Here's a link to an old reddit discussion of this: https://www.reddit.com/r/3Dprinting/comments/b22gml/lead_screws_vs_belt_drives/
However, I don't think there's anything to stop us from putting the motor on the bottom instead of the top.

[TheOnlyMann]

as of current design, unless we use a belted gearbox, or move the leadscrew position, there doesn't seem to be a easy way to move the leadscrew position to support the belts.
I might be missing something, but do comment upon!

[jyjblrd]

I tend to agree with @ehegenberger on this one. A belted z axis just seems like another mod you can slap on top of your printer (3d printer nerds are famously obsessed with adding all kinds of strange mods to keep themselves busy, this project is just an extreme example of that I guess lol)

The only benefits I can think of are:

1. reduce wear on the lead screw, as the z axis is very very active in non-planar printing
2. improve packaging (eg. the z axis motor can be moved to the bottom easier)

The downsides:

1. introduces slop due to belt stretching, especially with the gearbox
2. much more complicated (more pulleys, belt tension systems, gearboxes etc.)

I'm pretty sure your linked video explains those downsides in it and comes to a similar conclusion

[ehegenberger]

Yeah, I see it's not trivial to flip the Z-axis lead screw on its head with the current configuration, but it's definitely possible. One thing I really like about this design is that the (physical) X-axis origin is about as close to the Z axis as can be. In my mind, that should help reduce asymmetric loading on the Z axis, though I'm a ChemE, not a MechE, so I'm more familiar with A + B <-> C + D rather than X, Y and Z. 😆

[TheOnlyMann]

ill see what i an do. thanks for the input
Edit: while i think there is a good reason to stick with leadscrews, i feel like it's pretty hard to mount the motor still due to the position. and due to its position being probably crucial for lifting the carriage(its near the LM guide) i dont think it's really possible to move the motor without doing extra work like a belted gearbox(which goes against the initial idea in the first place)
while I cannot come up with more ideas, I'll just keep this in the back of my mind!
one good thing is that Chuckles182 has designed a newer motor mount to make it possible to install normal nema motors and a separate leadscrew. which partially solves my problem(it still gets mounted on top, but i think its easier to fix separate mounted leadscrew than normal ones)

[ehegenberger]

If the second, "rear" linear rail for the Z axis is not superfluous, I think it could be moved out to the "front," and the motor and leadscrew could then easily be inverted and located between these two linear rails. A second vertical extrusion could be added to help secure the resulting "front" linear rail if necessary. This would admittedly add some complexity but might even enhance the rigidity of the design and would not add any moving parts.

The next step from there would be to place the entire Z axis on a turntable, enabling the printer to reach and service multiple fixed build plates. Or just mount the whole thing on wheels and send it out to where people need prints.