by 3DAndy, published

MiniExtruder by 3DAndy Jan 24, 2013


A very small extruder, ideal for multi-color or multi-material 3D-printers.
The design is derivated from the multi-material-extruder from RepRapPro.

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RepRapPro has a Nema17 version in use with the Mendel - should be available for download from their github-repository (https://github.com/reprappro/E....

Best wishes
3D Andy

Anyone with a nema 17 version of this?

Hi, sorry this extruder is designed for 1.75mm only - I don't know,if it is strong enough to handle 3mm filament :-(

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MiniExtruder by 3DAndy is licensed under the GNU - GPL license.

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The original design of this extruder comes from Adrian Bowyer (first seen on vimeo vimeo.com/54462325), I have just slightly modified it. The extruder body is modified to use a tongue to hold the bowden tube - so eMaker-Huxley and RepRapPro hot-ends should fit without problems (and without any adaptions). The second change to the original design is the screw hole for the idler (idler screw only can be removed, if the stepper motor is dismounted). And I have made a change to the grub hole in the small gear to make the nut retainer a little stronger. If you want to have a look to the original files please visit: github.com/reprappro/Mendel.

Update V2 (3 Feb 2013): assembly instruction added; V2-extruder-block added (moved filament-drive-axis 0.5mm for better fit of hobbed bolt; larger hole for idler screw); deeper hole for motor flange (better motor fitting if your printed bridges are not perfect).
Update (24 March 2013): OpenSCAD sources added (they are not really nice - but better than nothing)

Watch this extruder in action: YouTube ( youtube.com/user/3DAndyAustria ) – there you can find an assembly instruction video also.

Some pictures of the mounted extruder could be found on Flickr ( flickr.com/3d_andy ) - there you can see also the mounting kits for M8 or M6 threaded rods (and of course assembly pictures).

Needed parts to build one extruder-drive:
- 1 of each: extruder-body.stl, small-gear.stl, large-gear.stl, tongue.stl
- 1 M3x5 set screw
- 1 M3x12 bolts
- 2 M3x16 bolts
- 2 M3x30 bolts
- 4 M3 washers
- 4 M3 nuts
- 1 M3 nylock nut
- 3 623ZZ bearings
- 1 hobbed bolt (need one? Find me on eMAKERshop ( emakershop.com/Seller=2273 ) or write a private message on thingiverse)

For mounting the extruder to the top of a Mendel/Prusa (with M8 rods) you will need:
- 2 mendel-mount-front.stl
- 1 mendel-mount-rear.stl
- 3 M3 nuts
- 1 M3x16 bolt
- 2 M3x25 bolts

For mounting the extruder to M6 rods you will need:
- 2 huxley-mount.stl
- 2 M3 nuts
- 2 M3x20 bolts

Good luck!


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Kenzu on Mar 25, 2014 said:

Anyone with a nema 17 version of this?

3DAndy on Mar 25, 2014 said:

RepRapPro has a Nema17 version in use with the Mendel - should be available for download from their github-repository (https://github.com/reprappro/E....

Best wishes
3D Andy

jameghino on Mar 9, 2014 said:

Is this for 3mm filament? Is not, do you have a version for 3mm? Thanks a lot

3DAndy on Mar 19, 2014 said:

Hi, sorry this extruder is designed for 1.75mm only - I don't know,if it is strong enough to handle 3mm filament :-(

plexer on Sep 16, 2013 said:

Any particular instructions for printing this to get a nice usable finish?

3DAndy on Sep 25, 2013 said:

No, not really. I printed my extruder drives with a 0.3mm nozzle and a layer height of 0.2mm. My parts work fine - without any special printing options or manual cleaning of the parts.

benhowes on Jul 10, 2013 said:

Hello, I've printed this (a few times now!) and I am finding that the gears don't quite mesh since they're a little too far apart. I'm wondering if I am loosing the ends of the gear teeth because I'm printing on a 0.5mm hot end. Should this be okay?

3DAndy on Sep 25, 2013 said:

Hello, sorry for answering so late - I didn't see your comment (no e-mail from thingiverse?). I printed this extruder parts several times before and didn't have any problems with the gears. I use a 0.3mm nozzle, a layer hight of 0.2mm and PLA-filament. This print-setup works very fine.

Jasper1984 on May 21, 2013 said:

I like it, but some notes about coding:

You know instead of making comments `//This is thing` you can just make a module and say `translate(to_position) thing();` Also `for`can save a dozen lines in some places. For instance where it says //XXX anders:

translate([0,-2.5,2.6/2]) for( y=[0,5,-5,10] ) /// XXX ANDERS!!!
translate([0,y]) difference() {
cube([20,3,2.6], center=true); /// XXX ANDERS!!!
cube([19.2,2,2.6], center=true); /// XXX ANDERS!!!

That said, the code for the original you started from is far from perfect. (Not that i expect perfection :), neither are mine)

Oh, if happen to want it cleaned, I already have done it a bunch, I can post it somewhere if you wish. I want to make the E-motor easily removable and add the ability to configure it for the hobbled bolt. http://reprapworld.com/?produc...

Of course that'd lower the gear speed ratio, by about a factor two, if the servo is not ok with that.. hmm i have a problem. (maybe a need to start from scratch problem)

3DAndy on May 21, 2013 said:

Thanks, if you wish I can publish your cleaned code here (I wrote you a PM).
The support thing is for the idler-bearing-hole (to create a nice rectangle to fit the idler bearing).

thantik on Apr 2, 2013 said:

Thank you for posting this. The inner-toothed gear idea is fantastic, allowing for a higher gear ratio in a small space. I'm currently working on a NEMA 17 derivative.

watsdesign on Jan 25, 2013 said:

ah thanks for having exported it ! I tried too but failed even with the missing library