VORON Flex Bowden Extruder

by russiancatfood, published

VORON Flex Bowden Extruder by russiancatfood Mar 14, 2016
8 Share
Download All Files

Thing Apps Enabled

Order This Printed View All Apps




VORON Flex Bowden Extruder by russiancatfood is licensed under the GNU - GPL license.

Liked By

View All

Give a Shout Out

If you print this Thing and display it in public proudly give attribution by printing and displaying this tag.

Print Thing Tag

Thing Statistics

13546Views 2341Downloads Found in 3D Printer Extruders


Overview: https://www.youtube.com/watch?v=8s7HgMFrdTg


REV A1: Enlarged the hole for the set screw in case the motor shaft is not keyed (D shaped).

REV A: I've ran into some issues with the design when it comes to flexible filament, and fixed them. The flex filament still has some path to get around the drive gear, because the piece of PTFE tube could be pushed up. The tubes also likes to be pulled down. The solution was to shape a channel for the filament in printed plastic, and add a bolster that filled the space between the top curve of the drive gear's tooth channel. Now the flexible filament will just slip, like any filament should, instead of jamming the gear.

Also added 3mm versions of parts that needed modification

I finally have an extruder I'm happy with. Easy access, and 70mm/s retract speeds. Oh, and I can print 1.75mm Ninjaflex. :)

You are going to need the following things:

4 - M3 22mm hex head screws
1 - M3 hex nut
1 - M4 14mm hex head screw
1 - M4 hex nut
1 - MK8 Drive Gear
1 - 625-2RS ball bearing

You'll also need a BSP bowden coupling (1/8) and about 40mm of bowden tubing

Insert the bowden tubing in all the way and shape it with a razor blade using the printed body as a guide. Then pop in the screws and attach the whole thing to the motor. Line up the key on the motor with the slit, slip on and align the MK8 drive gear and tighten it

Print Settings











More from 3D Printer Extruders

view more

All Apps

3D Print your file with 3D Hubs, the world’s largest online marketplace for 3D printing services.

App Info Launch App

Auto-magically prepare your 3D models for 3D printing. A cloud based 3D models Preparing and Healing solution for 3D Printing, MakePrintable provides features for model repairing, wall thickness...

App Info Launch App

Kiri:Moto is an integrated cloud-based slicer and tool-path generator for 3D Printing, CAM / CNC and Laser cutting. *** 3D printing mode provides model slicing and GCode output using built-in...

App Info Launch App
KiriMoto Thing App

With 3D Slash, you can edit 3d models like a stonecutter. A unique interface: as fun as a building game! The perfect tool for non-designers and children to create in 3D.

App Info Launch App

Print through a distributed network of 3D printing enthusiasts from across the US, at a fraction of the cost of the competitors. We want to change the world for the better through technology, an...

App Info Launch App

Quickly Scale, Mirror or Cut your 3D Models

App Info Launch App

3D Print a wide range of designs with Treatstock. Easy to use tools to get the perfect result. The global 3D printing network that connects you with high-quality and fast working print services nea...

App Info Launch App

where do i get the BSP bowden coupling (1/8)? banggood? gearbest?..

Can you please give me advise on install. I'm totally confused. I printed the 1.75mm body and mine is flipped. I.E If I mount the way you have it, the exit side for filament is facing down not up. Can you please help.

Really clever design. It works very well.
The best, easy to use Bowden Extruder I have tested so far.
Thank you for sharing.

you still using this with success? did you print flexible filament?

I am still using this without any problems.
The only thing I have changed was making a longer latch so I need less force to open/close it.

No, I haven't tried flexible filament. Only ABS, PLA and PETG.

Why is a 625 bearing used but I saw no mention of a 5mm bolt that it would require? The 625 mentioned shouldn't that have been a 624zz instead?

The IdlerSetPin.stl is just a snap fit part that you print and use

I love how easy it is to load filament into this extruder. I was wondering if you make a version for a non grooved gear and grooved bearing?

Outstanding extruder. Great design. I'm printing NinjaFlex fast as well as anything else. Many thanks!

I've printed this and am struggling with assembly, mostly due to my print is flipped from the pictures and video...

indeed mine printed flipped as well .. that much effort put on the design and at least SOME instructions would be expected but are totally missing .. besides that M3x22 - no such standard ffs ..

Is there/will there be a version for Planetary geared stepper motors? The mount screws can be dealt with but the shaft for those kinds of motors has a larger diameter (regularly D-shaped 8mm).

I'm a little confused with how this design works with the PTFE tubing. I made a 1.75mm verson, however it doesn't have nearly enough space for the tube to fit, and instead is a tight fit directly onto the filament. Thanks for an awesome looking design!

I'm having the same issue as @mhigginsmoy. Is the 3mm version supposed to fit the tubing, and the 1.75mm version supposed to allow only the filament through?

I can't seem to get a good copy of the stp off your github. Solidworks is saying it's an incomplete file. Am I doing something wrong or is it not all uploaded? Thanks!

Should be all there. The CRC checks out. Did you try cloning the repo and pulling the files from that?

SW may be complaining that it's not a parametric model, which it isn't.


Are the Solidworks files available somewhere? Converting the STL to solidworks files takes an eternity.


I figured out the issue. The problem was between the keyboard and chair! Got it all assembled and am loving the results. The snap closure is intense!

I had to do quite a bit of clearance grinding because I have one of the MK8's that has a thicker flange at the setscrew. Thank you for providing steps so I can make a version specifically for my setup.

Can you recommend layer height?
I would love to try this. I tried to print the body ver A1 already (0.1mm layer height, ABS), but could not fit my 1.75mm filament through the hole... Should I drill it?

I printed it in 0.2 for strength.

Drill it! Use a 2mm drill (or the closest Imperial cousin)

Ok, I will :) Thank you!

Comments deleted.

Printing this out as we speak in PETG. I cant wait to give this a shot with ninjaflex. I have never once completed a full print in ninja flex with my bowden setup.

Just remember, this thing does not defy the laws of phisics. Just gives you a better chance. Go slow, and watch the retract speed.

Well this is a huge step up from my current bowden extruder (the stock model on the Fusematic printer), so I have high hopes. Is there a certain width PTFE that works well with this? I have 4mm outer-diameter tubing and it seems much bigger than the printer part (the 1.75mm version).

4mm is pretty standard to 1.75mm filament. That's what I have tons of, and that's what I designed for.

Hey @russiancatfood! This thing comes together great, however I'm currently having issues where the shaft for the MK8 gear is grinding up against the set screw on 1 side.
This is without a doubt a printing issue where I'm off-dimensions, but, it could probably use maybe 1mm more gap if possible.
Obviously any such change shouldn't interfere with the PTFE feed tubing being directly on the gear.

edit: I filed it out a bit, and now its working fantastic! Maybe something to keep in mind though :)

edit2: I also had to zip-tie the bowden mount as when I was screwing it in the whole mount de-laminated in the middle.

edit3: I re-printed in PETG. I don't recommend PLA for this part.

edit4: Still grinds a little in that shaft at high extrusion speeds, going to file it once more.

I realized the clearance issue can be caused by some people not having a D-cut motor shaft. I'm going to add more clearance for the set screw to both main body parts.

Ah, yes. The part is designed for ABS or PETG. PLA doesn't have the mechanical properties required to make this work well.

Glad you are printing again!

Comments deleted.

Despite having issues with clearance, I actually do have a D-cut motor shaft. In any case, I'm going to try the REV A1.

On another note, what is with the little paddle feet? They're a real pain and unnecessary?

Those are adhesion pads and are meant to be removed after printing :)

Its just 1 more thing to clean up and quite annoying since it makes my bottom layer less clean.
We all have our own way of making that first layer stick, I'd rather not have the paddles forced on me (IMHO).

Comments deleted.

Any reason not to fit the motor more snug? Mounting this is a bit wobbly because of the air gaps under each corner.
Why not just fill that in?

It was designed this way for ease of printing. No supports needed. What air gaps are you referring to? Got a picture?

All good, I had a shower and thought about it and realised you've done it for ease of printing.
I might make a 'filler' base plate such that there isn't a gap in between the motor and the extruder

I like it. Added "Brace (Back)"

Awesome! Beat me to it.

Upon further tests, 3 nylon M3 hex nuts also work perfect as spacers.
I'll let you know if the braces work better.

edit: The M3 hex nut spacers work better IMHO.

Comments deleted.
Comments deleted.

Mk8 seems too small, can you share file so I can make it for Mk7 or you could make it for MK7.

One more Question,

What I you using to hold the PTFE tube. Doesnt look like a regular Brass Pneumatic holder.

It's a BSP 1/8 fitting that you get with any E3D Bowden kit. Pretty much any 1/8 BSP fitting will work.

Where are you getting the bowden adapter? Ive searched around and the only place I can find one is in the UK (Im in the US). Google searches have returned nil on the one you are using in the pictures.

The one I'm using comes with any E3D kit if you select the bowden option. This guy: http://e3d-online.com/Mechanical/Bowden/Threaded-Bowden-Coupling-1.75mm-Filament

This part will fit (even thought it says it won't), and ships from US: http://www.ebay.com/itm/1-8-Push-In-Fittings-For-4mm-OD-PTFE-Tube-For-bowden-extruder-1-75mm-3D-Printer-/261758913320?hash=item3cf20c0b28:g:AB4AAOSwBahU0b9g

This seals my decision to include this adapter in the hardware kit.

EDIT: Or you can get them from McMaster: http://www.mcmaster.com/#7880t349/=11nz1in

Design looks very promising, can you modify this for m6 bowden coupling and a 608zz bearing?
Cant wait to try this out on my printer

608 bearing won't fit into the design as it's too big. Bringing the tension arms out that far will push the mechanical limits of what printed plastic can do.

M6 (or 3mm, or 2.85mm) tube version is already uploaded.