Hey! This thing is still a Work in Progress. Files, instructions, and other stuff might change!

Bolt filament feeder

by gringer, published

Bolt filament feeder by gringer Dec 9, 2012
0 Share
Download All Files

Thing Apps Enabled

Order This Printed View All Apps


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

3574Views 669Downloads Found in 3D Printer Extruders


Alternative filament feeder that uses a bolt directly attached to the stepper to feed filament.


Download and print bolt_feeder_base.stl, then join together with 4 3mm bolts. The bolts act as a friction hold to adjust the tension on the filament. There is space left for brackets to be placed where the bolt holes are. The filament comes out of the exact centre of the model, which should make joining this with other extruder brackets a bit easier.

Still to model:

  • brackets for mounting to hot end, stepper motor
    • joiner to connect stepper motor to bolt head

I got frustrated with the extruder feeder clogging up with bits of PLA, so had a think about what other mechanisms I could use to feed the filament, preferably without the need for purchasing extra metal parts. This is my first attempt at something a little different that feeds the filament directly beside the bolt, using the bolt thread to push the filament.

Initial model:

  • M8 thread depths were taken from http://www.newmantools.com/tech/threadm.htm
    Update 1:
  • added 0.25mm to circle radiuses to account for extrusion width
    Update 2:
  • modified enclosure (hopefully a near-final design) to hold full length of bolt and support brackets

The openSCAD file has variables for almost all the things you might want to adjust. In particular, bolt/screw length, bolt/screw diameter, and filament diameter.

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

Screw threads are intended to have blunt peaks.  I might try cutting a sharp threaded screw on a lathe so you get better bite into the filament with less force.  Is there a problem with the filament wanting to twist?

That's actually a problem with my current feeder (which uses a custom knurled bolt), because the filament already wants to twist -- I wonder if the bolt was cut using some mechanism that encouraged twisting. Looking at the filament when it comes out of the threader (I bought a reprap with a bowden cable), you can clearly see that the filament is slipping when the desire to twist (or not) exceeds the insistence of the bolt to continue on straight (or twist).

I'm hoping that using the normal bolt thread will reduce this issue. In my current hand-driven tests, I've had no problem so far with slipping due to twisting.

Although it was abandoned this idea looks a little different. I say go for it and see how it works.
Another option is to increase the diameter of the drive wheel like the solastruder design http://www.thingiverse.com/thing:17783http://www.thingiverse.com/thi...
I have been using one for about 9months and it is a great design.  

VM Extruder

This is like the original Reprap design. Research that and see why it was abandoned.

 You mean the darwin one (e.g. http://reprap.org/wiki/ThermoplastExtruder_2_0)?http://reprap.org/wiki/Thermop... I'm not sure what you're suggesting is the 'failed' design.

My intended design will use no gears. The wheel you see on my sketches is just a free-wheeling pressure hold (a flat cylinder with an indentation in the edge). The filament is driven directly using the thread of the bolt, rather than any gear teeth.

Regardless, failure at this project will only give me more insight into how fickle the filament thread is.

@ronthomp You're not really giving me a chance to see things from your point of view. Could you please confirm that the design I pointed to is the one you were referring to when you mentioned "the original Reprap design"?

 I didn't say it failed. I said it was abandoned, as in for better designs.