Direct Granules Extruder, FDM prints from powder

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:

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!

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:

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:

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.

I have been shrinking the tube of my extruder in order to reduce friction and so to get a better retract:

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:

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.

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.

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