Belt driven extruder with a stationary motor?



  • This guy built a contraption with a corexy variant that cal also tile the carriage with a third stationary motor.

    I wonder if a similar arrangement would work for a 3D printer, having a direct extruder driven by a belt and a stationary motor.

    https://www.youtube.com/watch?v=myO8fxhDRW0

    Any thoughts?


  • Moderator

    @zapta I think it's a Markforge axis (for the tilting) on top of an H-bot. I think I've seen extruders driven in this way, somewhere, but can't find it now. Of course, you then have to get the extruder moving relative to the X and Y axis, but should be possible with kinematics settings in M669. You would need to have gear reduction on the hot end to drive the filament, so the extruder stepper could keep up with the X and Y steppers. But then you're only reducing the weight of the axis by the stepper motor (and pancake steppers are pretty light nowadays) for a big increase in drive complexity.

    For remote-direct-drive extruders, I thought this one was interesting: https://community.ultimaker.com/topic/16452-zero-gravity-direct-drive-extruder/
    He even made a dual-tool-changer version: https://community.ultimaker.com/topic/19345-zge-mark2/

    Ian



  • For remote-direct-drive extruders, I thought this one was interesting: https://community.ultimaker.com/topic/16452-zero-gravity-direct-drive-extruder/
    He even made a dual-tool-changer version: https://community.ultimaker.com/topic/19345-zge-mark2/

    Ian

    Interesting that you found that extruder 🙂

    I have been running the ZGE extruder on my UMO+, with an UM2 printhead, for ~3 years. It's one of the best upgrades I made. Another guy, who prints tiny details, has 3 printers with that extruder in his shop.


  • Moderator

    @nilrog In my last job I looked after a couple of UM2+ printers. They were forever popping the Bowden cables out of the extruder, so I looked around for a direct drive replacement, then saw the ZGE. Managed to fix the Bowden tube problem eventually (a combination of oversize filament, broken compression fittings and partially blocked nozzles) so never got around to making one, but filed it away in the back of my brain under 'someday, maybe'!

    I understand gudo, the guy who designed it, passed away not long after, but I think you already know that... https://community.ultimaker.com/topic/23576-gudo-the-humble-man-with-great-ideas/

    Ian



  • I'v seen somewhere a I3 style printer with all stationary motors ... the X motor was on bottom next to right Z motor running hexagonal rod driving the pulley moving X belt and on the other side and next to left Z motor there was extruder motor running hexagonal rod driving 45 degree printed gears driving another hex shaft driving the extruder ... it looked super weird, no clue how it worked I only seen images .. probbly reprap forum but I could be mistaken and I think it was before I had my second kid so 3+ years ago .. dunno if that machine was inspired by the ZGE or ZGE was inspired by that machine but I'd actually love to see that thing in action 😄



  • @droftarts said in Belt driven extruder with a stationary motor?:

    I understand gudo, the guy who designed it, passed away not long after, but I think you already know that... https://community.ultimaker.com/topic/23576-gudo-the-humble-man-with-great-ideas/

    Yes, I wrote that (sad) post 😞

    I have, what is probably his last design, from an idea I had. He had created a coreXY mod for UM2/UMO+ and I wanted to put together a 2Go version of that. So we were communicating and I was hoping he could share the parts he used (they were not public at that time) so I could try to fit them on my custom frame...but he asked for the file for my frame and when he came back I got a complete step-file of the printer I had described to him ♥

    That design, and the one for the big UM2/UMO has now been made public by @neotko who helped Gudo a lot (and is the one who runs those printers almost 24/7).
    https://www.thingiverse.com/thing:4153081

    The only issue I have had with the ZGE is that the printed part that drives the Bondtech gears breaks after many hours of use. So I redesigned it to use a piece of aluminium tube instead. But I still run 2.85 filament that, I believe, puts more strain on that part than if you, like Neotko, use 1.75 filament.

    Some call the ZGE over-engineered...I say it is an excellent solution to have direct drive on a "weak" gantry like the UM's have.



  • That's the first time I've seen the ZGE...

    That's a very novel way of doing it! I'm very impressed.

    A spline shaft is a way better way of driving an extruder compared to a belt, it can handle a lot more torque.
    I would probably have used Igus square shaft and bearings, but my days of modifying existing printers with self-printed parts are long gone.

    Those things must look crazy when they are running.

    [starts thinking about how you would do something similar for a delta...]



  • @theruttmeister
    If you want to see more of the ZGE in action there are lots of videos posted on Twitter, @neotko being the top poster as he does some crazy things with his printers, with the hashtag gudozge:
    https://twitter.com/search?q=%23gudozge

    And more can be seen with the hashtag gudoxycore where it is combined with his coreXY mod:
    https://twitter.com/search?q=%23gudoxycore


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