Direct Granules Extruder, FDM prints from powder

Description

For this year's Hackaday Prize I dive deeper into 3D printing. The aim is to reuse waste prints with a direct granules extruder. I got this working nicely during the past weeks and I also discovered a way to use industrial pellets as raw material, replacing the need for filament (on plastic spools). Another benefit of using granules as raw material is the capability of printing a wider range of materials that are otherwise too soft or to brittle to be processed as filament.

The extruder is meant to be a drop-in replacement for existing desktop filament extruders with no additional electronics needed, thus it is working with a relatively weak stepper motor and uses one normal heating cartridge. The print quality will be at least close to that of filament printers. No extruder you can buy anywhere, yet!

Details

With my machines I aim to give students a better understanding of how technology works and of course I'd like to drive innovation as well. "Keep things simple" is the mantra that I follow. Simple to build, out of parts that are simple to source and bring it to live with simply some lines of software code.

I am fighting common thoughts that complex machines like 3D printers must be composed of complex parts manufactured with complex machinery. I am replacing expensive tool chains with my brain ;-) That often means breaking with conventional ideas.

Done:

- Build a reliably working extruder prototype (V5).

- Create build instructions (including video), even so it is a prototype made following my intuition.

- Explain in detail how the extruder works and so why normal wood screws are better than anything else: In contrast to conventional extruders, the forwarding happens in the cold zone only.

- More details about how to print with household sugar and so using materials with essentially different properties than common FDM materials.

Done, but not explained in detail, yet:

- What to consider when preparing raw material

- How to feed the extruder with conventional, industrial pellets

- Find ways to convert waste prints into new raw material for the extruder

To do:

- More print tests with a larger variety of raw materials

- Build version 6 with series production in mind instead of the handmade version 5

Files

Rocket.zip

openSCAD and stl files of the Rocket I have printed as a test run of the extruder.

Zip Archive - 311.58 kB - 11/07/2021 at 07:27

Download

Build-Instruction-Extruder-V3.pdf

Build instruction of Direct Granules Extruder V3. Keep in mind, that this handmade prototype was largely build using the rule of thumb.

Adobe Portable Document Format - 391.30 kB - 10/25/2021 at 08:40

Preview

Extruder-V3.zip

3D files of the printed parts needed for Extruder V3 (STL and OpenSCAD)

Zip Archive - 3.95 MB - 10/25/2021 at 08:33

Download

warping.zip

Python scripts that generate G-code files to minimize warping of 3D prints. The scripts generate G-Code for a gear rack and a box.. Also included are stl files of such a gear rack and box.

Zip Archive - 709.24 kB - 09/03/2021 at 10:43

Download

RobotArm-v1_0.zip

The Python script (tested on Debian Linux) and Arduino sketch I have written for my robotic arm v1.0 You can control the robotic arm with your keyboard and store/replay movements.

Zip Archive - 5.97 kB - 08/19/2021 at 06:17

Download

Components

1 × Aluminum bar 16x16, 300mm length

1 × Aluminum plate 3x65x130mm

1 × 3mm threaded rod 1m

1 × Glass block 25x25x8mm

1 × Teflon tube 8mm inner diameter

Project Logs

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Meanwhile, close to a _normal_ printer
Norbert Heinz • 09/29/2024 at 15:21 • 0 comments

I have modified the mechanics of the Prusa again. This time I had an eye on better usability of the printer. Furthermore I am working on the automatic material feed. The parts needed for this were all printed from PLA powder. The machine gets closer to a printer that is almost like a _normal_ (filament) printer:
The full print of a small part is demonstrated in another video:
First 3D Benchy printed from PLA granules
Norbert Heinz • 09/07/2024 at 10:49 • 3 comments

The load cell of the Prusa MK4 is implemented and so bed leveling works fine. Now that larger prints can be carried out, I have made a Benchy:

If you know a granule FDM printer that can make better looking Benchies, leave a comment!
Extruding PLA powder required changes in the design
Norbert Heinz • 07/22/2024 at 14:10 • 0 comments

I got some PLA powder and trying to print with this raw material didn't work with version 5.0 of my granule extruder. I had to shorten the extruder tube (again) and make some more changes to the hardware, but now printing with the powder works:
My Prusa MK4 no longer needs filament to print
Norbert Heinz • 06/07/2024 at 13:57 • 1 comment

I am in the process of converting a Prusa MK4 to granule printing. Part 1 of the process shows how to build the core component, extruder V5.0 and first test prints:
A closer look at the auger screw(s) of my direct granules 3D printer
Norbert Heinz • 05/10/2024 at 11:40 • 0 comments

The simplest component of my granule extruder must meet certain criteria to get a working 3D printer:
Next step: Converting a Prusa MK4 to direct granule printing.
Extruder V4.1: Rough build instructions and thermal optimization
Norbert Heinz • 04/27/2024 at 12:54 • 0 comments

I have been shrinking the tube of my extruder in order to reduce friction and so to get a better retract:
V4 of my granules Extruder has a full Metal Core
Norbert Heinz • 04/06/2024 at 10:05 • 0 comments

Version 4 is made of a brass / stainless steel tube and has of course a simple wood screw an auger:
A 20 minutes test print of a tiny 27x25x12mm track link shows the capabilities of the new design:
Let's have a look at the energy needed to grind PLA pellets
Norbert Heinz • 03/17/2024 at 13:53 • 0 comments

To get a better idea how to improve my pellet grinder, I had a closer look at the energy needed to turn pellets into powder:
With the simple experiments carried out in the video, you get a better idea of what material throughput a low power router turned into a plastic mill can deliver.
Get raw material for my direct granules extruder
Norbert Heinz • 03/01/2024 at 11:41 • 9 comments

My "old school" way of getting raw material was using a blender and a sieve to get grain sizes of 2mm and less:
The resulting grains under the microscope:
To get fresh material from industrial pellets, I have turned a router into a grinder:
With that, the resulting grain size is less than 1mm:
Future tests will show, if the smaller grains can be used to design a smaller extruder.
Cookies 2.0 with a paste extruder
Norbert Heinz • 12/22/2021 at 16:05 • 0 comments

While waiting for parts to arrive for my granules extruder upgrade, I have created a syringe based paste extruder:

View all 25 project logs

Build Instructions

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Why there is no step by step build instruction for Direct Extruder V3, but of course an instruction exists

Direct Granules Extruder V3 is a prototype you can build from cheap, commonly available materials with low tech tools. It is not for beginners in 3D printing, but advanced tinkerers should be able to make a copy. Since not being intended for beginners, I don't provide a step by step build instruction. Instead you get drawings and pictures in the "files" section that should enable you to create your own extruder.

Another issue is, that this design is based on other physical principles than existing extruders. It is essential to get a deeper understanding of those principles that I have described in the logs of this projects that also include videos.

Leave a comment if you still have questions about the build process of the direct extruder.

Discussions

benjjyman wrote 11/07/2021 at 11:51

1 can we vote for you?

2 one problem with design is ptfe tube for use with recycled ABS, or Nylon or anything above 260 degrees celcius , other than that this brilliant

3 could you please explain warping python script ?

Are you sure? yes | no

Norbert Heinz wrote 11/07/2021 at 14:43

(1) You can like my project (on top of this page), but votes are up to the Hackaday Price jury.
(2) Yes, in a future design, the PTFE tube will no longer reach into the hot zone.
(3) What explanation is needed? It was just a proof of concept, not yet meant to be an implementation in a slicing software.

Are you sure? yes | no

heinz wrote 10/23/2021 at 04:05

Nice, I'm a fan of your design style.

How is the screw located in the whole assembly? Does the screw end where the teflon tube ends and the 1.5mm rod continues to go into the heater block?

Are you sure? yes | no

Norbert Heinz wrote 10/23/2021 at 11:17

Thanks! Right now I have added a log entry with a video, that will hopefully answer your question: https://youtu.be/oH-e_poDeYE

Are you sure? yes | no

heinz wrote 10/23/2021 at 14:07

Ah okay, screw ends on the cold side or a little bit beneath. Didn't realize the 1.5mm is rod is for sealing the nozzle on retraction, thought it had some stirring function.

Are you sure? yes | no

nodemcu12ecanada wrote 08/23/2021 at 14:24

Very inexpensive 6 degrees of freedom robot arms are readily available.

You have to get a power supply and do the controls yourself. I used a $4 NodeMCU.

https://hackaday.io/project/177278-robot-arm-with-web-page-hmi

Are you sure? yes | no

Norbert Heinz wrote 08/23/2021 at 15:03

I never said, my robot arm was the first and only one. ;-)

Countless arms using RC hobby servos exist, I also have built one before:

https://homofaciens.de/technics-machines-robot-arm-v0-1_en.htm
These are all interesting devices to learn basics about robotics. Add some new design details to the army of DIY robots is why I created mine from wood.

Are you sure? yes | no

Jason wrote 08/18/2021 at 21:35

Super cool! I'd love to see some details and files that I could use to put together kits for local schools!

Are you sure? yes | no

Norbert Heinz wrote 08/19/2021 at 06:24

Thanks! Sorry, I had forgotten to upload the file. The package is now available on Hackaday.
I have also added a link to my pages in the project log

Are you sure? yes | no

duda.sertorio wrote 08/18/2021 at 17:09

FANTASTIC ! FANTASTICO [pt_BR] !! CONGRATULATIONS ! PARABENS [pt_BR] !!

Are you sure? yes | no

Norbert Heinz wrote 08/18/2021 at 18:45

Thanks!

Are you sure? yes | no

Direct Granules Extruder, FDM prints from powder

Description

Details