We don’t know about you, but one of the biggest hassles of having a 3D printer at home or in the ‘shop is the space it takes up. Wouldn’t it be useful if you could fold it down? Well, you’re in luck because over on Hackaday.io, that’s precisely what [Malte Schrader] has achieved with their Portable CoreXY 3D printer.
The typical CoreXY design you find in the wild features a moving bed that starts at the top and moves downwards away from the XY gantry as the print progresses. The CoreXY kinematics take care of positioning the hotend in the XY plane with a pair of motors and some cunning pulley drives. Go check this out if you want to read more about that. Anyway, in this case, the bed is fixed to the base with a 3-point kinematic mount (to allow the hot end to be trammed) but is otherwise vertically immobile. That bed is AC-heated, allowing for a much smaller power supply to be fitted and reducing the annoying cooling fan noise that’s all too common with high-power bed heaters.
The XY gantry is mounted at each end on a pair of scissor lift mechanisms, which are belt-driven and geared together from a single stepper motor paired with a reduction gearbox. This hopefully will resolve any issues with X-axis tilting that [Malte] reports from a previous version.
The coarse tramming is handled by the bed mounts, with a hotend-mounted BLTouch further dialling it in and compensating for any bed distortion measured immediately before printing. Simple and effective.
As will be clear from the video below, the folding for storage is a natural consequence of the Z-axis mechanism, which we reckon is pretty elegant and well executed—check out those custom CNC machine Aluminium parts! When the Z-axis is folded flat for storage, the hotend part of the Bowden tube feed is mounted to a pivot, allowing it to fold down as well. They even added a pivot to the other end of the cable bundle / Bowden feed so the whole bundle folds down neatly inside the frame. Nice job!
If you want a little more detail about CoreXY kinematics, check out our handy guide. But what about the H-Bot we hear you ask? Fear not, we’re on it.
This is brilliant. There are a lot of appliances that compete for space and this could fit in a drawer. Maybe a bellow for an enclosure and then it would fit the needs of a lot more people.
I wonder how stable, the X axis is: How large wobble during movements?
It can be quite stable (see chem/physics laboratory liftboys) but this thing seems to use belts to move scissor endpoints.
I’d have expected screws (with maybe a single motor driving both via a single belt) – this would be inherently stiffer I think (maybe with flat bearings at all screw shaft endings).
That would be my concern – those centre bearings are doing a lot of work.
The print looks good, but I wonder what the 100th or 1000th print would look like.
This is super neat, even if it’s late to the party with the Positron having been out in the wild for a while.
I saw a recent video where the Positron team talked about the desktop appliance-like nature of a foldable printer (in reference to the rationale behind the upcoming larger Proton). While this one doesn’t seem to have a comparable folded-footprint-to-build-area ratio, its upright orientation and natural self-folding definitely makes this one a better fit for the job of a “put it away when you’re not using it” kind of printer.
Plus, the look of the scissor lift is just darn cool.
“put it away when you’re not using it kind of printer.”
Hmm you know the printer as an appliance made me think,
A little design modification and you could mount this in an undercabinet configuration so the build would descend as the model “grew” then tuck itself away afterwards.
Reminds me of:
https://hackaday.com/2019/10/02/x-printer-fits-in-a-backpack/
I also like this presentation:
https://www.youtube.com/watch?v=nRvL-KlX-9w
It shows his thought child from multiple directions so you have a much better idea of construction details, and he’s got some ideas for improvements. I like using lead screws instead of a geared stepper motor with belts for the Z-axis.
The best way to fix the X-Y wobble (also mentioned by Henrik above) is to connect the left side and the right side of the scissors together.
I designed and mad a resin 3d printer with this system some time ago…
https://www.youtube.com/watch?v=Jp6w0H66sAA
Shout out for the Lemontrin/Positron:
https://hackaday.com/2024/12/26/open-source-lemontron-3d-printer-is-ready-to-build
That is very very beautiful. I’m glad I don’t have the problem of space. I have a built in closet in my house where my printer is in, which also helps with sound as I covered the walls in sound dampening foam.
What a stunning piece of engineering. Especially with this time laps that I now watched 20 times at least. If it’s fast enough it would be cool as a portable printer.