Wall Delta Printer

Hey guys, i've been using a creality ender 3 for about a year now, and I have a little experience in part design and 3d printer designing and building, as my first printer was an anet a8 that didn't work, so all of the troubleshooting gave me plenty of knowledge. Now, as a side project, i want to try to build a reprap machine. So many other machines have designs and plans, but one that particularity interests me is the Wall Delta design. I'm working on designing a strong and printable bearing that could be used to hold rods in place, but before i go any further i want to get some feedback on the idea of the wall delta printer. Why aren't there any designs made yet? What are some cons to this design? Some pros i think are that it could be easily folded into a very small space, and carried around in a backpack no problem. What do you guys think?

... with this position-offsets and arm lengths the possible weight of the toolhead with filament and power feeder wouldn't be really usefull -- check for CNC-mill "wall"-designs with parallel kinematics and their geometries to get some "gut feelings" for needed stiffness and torques ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

It really is more of a proof of concept. Maybe you can find the original post here on the forums. Nicholas is a frequent visitor here and the video was used in one of his topics. If you can find back the topic, then in there will be all the info you need and you will see it's not a very viable concept sadly as VDX explained.

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http://www.marinusdebeer.nl/

Yeah, i realize the video was meant as a proof of concept that the delta towers can be placed in different locations, but i think there could be a real practical advantage to a printer like this, and i'm bored and have nothing else to do xD. I looked for that thread, but i never found anything else about it, the video and its comment section is all i have.

Edited 1 time(s). Last edit at 08/17/2020 08:52PM by Wi11y_G.

... another viable conept with a "sideways" kinematic with low footprint and "foldable" arms is a SCARA or better a "parallel SCARA" (for higher accuracy and stiffness).

Here is a good sample of a "parallel" - [www.youtube.com]

... or here, a DIY type - [www.youtube.com]

Edited 1 time(s). Last edit at 08/18/2020 02:10AM by VDX.

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

I immediately had to think of this 3DOF robot arm by skyentific haha:
[www.youtube.com]

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http://www.marinusdebeer.nl/

... from 5:20min you can see the "wobbliness" of this type of kinematics -- so here it's all for "stiffness" or high precision bearings ... so not really suited for high resolution/precision applications in the DIY-range.

But, with good (expensive) components, such systems are used for CNC-milling too

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Quote
VDX
... from 5:20min you can see the "wobbliness" of this type of kinematics -- so here it's all for "stiffness" or high precision bearings ... so not really suited for high resolution/precision applications in the DIY-range.

But, with good (expensive) components, such systems are used for CNC-milling too

I know, the wobbly characteristics of the machine were immediately apparent to me, yet I really do like the design

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http://www.marinusdebeer.nl/

Quote
VDX
... another viable conept with a "sideways" kinematic with low footprint and "foldable" arms is a SCARA or better a "parallel SCARA" (for higher accuracy and stiffness).

Here is a good sample of a "parallel" - [www.youtube.com]

... or here, a DIY type - [www.youtube.com]

I've been messing around with designs for a "wall SCARA" and I do think it's a better bet than delta. I'm hoping to keep the business end all up near the ceiling, with cantilever bed lowering down as it prints. And if possible, have the bed fold down when not in use to even further reduce the protrusion distance. One of the challenges is the elbow running into the wall. My first design has the bed rotated 25 degrees around the vertical axis to make room, at the cost of one bed corner sticking out farther from the wall. I was hoping to be able to do it super minimalist by using a single SBR12 rail as both the bed support and the axis for the arm (which guarantees that the direction of Z motion is normal to the arm's plane of motion), with a ballscrew to drive the bed up and down the rail as well as preventing the bed rotating around the rail. But unfortunately the machined ends of cheap Chinese ballscrews are not absolutely concentric with the screw thread, so it actually forces the bed to rotate around the rail by a small amount throughout each revolution of the screw, so it would produce ripples in the print which increase in amplitude as you get farther from the rail.

I'll probably revise it to use a regular T8 leadscrew instead of ballscrew, and a second linear rail to prevent rotation around the first (probably small diameter unsupported rail since there's very little force for it to resist). It would also be interesting to do parallel SCARA with two supported rails, with each arm using one of the rails as its axis. But then I can't use the 25 degree rotation trick to avoid elbows running into the wall, so the whole printer would need to be moved out farther.

I was thinking the same but for a foldable cantilevered arm, but also with core xy rig on the ceiling(or cut a hole in bedroom floor, not easy in a single storey ), or a really light axis/actuator/telescopic arm hanging from the H bar, though have to think long & hard about how big the bed could be....2m( or my 670mm LWF42) x200mmx200mm is not a volume I need, a rocket to the moon? 3D printed snooker cues? replacement broom handles?

Edited 1 time(s). Last edit at 08/28/2020 10:21AM by MechaBits.