REDRAPPER 3D printing with rack and pinions

I have had an idea floating around for increaseing the ammount of printed plastic parts in the reprap, It would use a printed plastic rack and pinion to move each of the axis.Im not sure if it would work, but I wanted to share the idea and get peoples opinions of it. The possible flaws and the positive aspects of it? It uses a bowden extruder so this should improve printing quality. The steppers are connected directly to the gear and the stainless steel bars are clamped in place using printed plastic bar clamps.The frame is wooden, but held together using angled printed plastic parts. Anyway ive attached an IGIS of the model, this is purely for explanation purposes, sizes gears and parts are not correctly sized. position of parts are not even in the exact place.


download the Iges model here


[github.com]

can you export a set to stl?

I havnt designed the rack and pinion yet, i have little experience with gears and designing them, the iges model of the whole printer is available in the link above. I will soon be looking at how to draw it, do you have any experience with gears?

yes, i use a program that designs gears for me. I just don't have a program that can read your *.igs files. Also I had assumed you were further along with your idea and had the files ready, and the gears made, since you were talking about rack and pinion and wanted to replace printer parts with it. there are others that are a lot further along with this approach. from where you are in the process, you will learn a lot from making the gears on your own. one of the links included includes an openscad profile for making rack and pinion.

look here:

[www.thingiverse.com]
[www.thingiverse.com]
[www.thingiverse.com]
[www.thingiverse.com]

I would suggest you search thingiverse.com and use Google for information about the rack and pinion setups.

there is considerable mechanical wear on parts, and lack of precision in making the parts. if helical is used there is little backlash and chatter. good luck with your project.

You can download the IGES file and load into FreeCAD and then export as STL.

FreeCAD is an open source 3D CAD program see [free-cad.sourceforge.net]

There should be a new version 0.13 around Christmas time.

It isn't very difficult.



I am thinking about a correction table for improving precision. I will add it into skeinforge or slic3r.

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Detlef

Excalibur Hotend

reprapclean32.png

reprapzone.blogspot.de

Hi yes here is the link for an stl of the printer, as i said i havnt worked on the properly just did a quick model as to where i would lay out everything.

[github.com]

ye cheers the links are very helpful i didnt realise people were using rack and pinions already, i was thinking of driving all the axis using this system, and possible a bowden extruder which would hopefully make the prints better quality.

wow they look amazing! how do they perform? any issues with it?

fredted1234 Wrote:
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> wow they look amazing! how do they perform? any
> issues with it?

Well, if you set the acceleration too hard, they will jump off the table, because there are no timing belts dampening the acceleration. It is like bungee jumping with wire ropes.

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Detlef

Excalibur Hotend

reprapclean32.png

reprapzone.blogspot.de