Hi ! I found 2 promising projects of such Pellet Extruders that are on the commercialization path.
Recently I wrote a short post about the Kickstarter campaign of the Gigabot Pellet Printer, where the print head is huge, heavy and pretty expensive: 1500$. The weight is probably above 1 Kg which is an issue and it cannot be used on many desktop printers.
Both projects seem to be much more mature from a development perspective than the Gigabot attempt, especially on the minimum nozzle size which is way too big on the Gigabot. Even if there is a very large volume, you need more precision than what they provide at this current stage.
The first project is from Mahor Muñiz, it seems that he iterated on his design since 2016.
There is still an early version of his extruder on Thingiverse: https://www.thingiverse.com/thing:1847917
There is some recent activity and the quality of the print seems correct.
This is a single heater design with a Nema17 geared stepper motor, the weight seems ok and the small desktop 3d printer do not have to struggle too much to print.
He has many other videos on his youtube channel.
Youtube: https://www.youtube.com/channel/UCttVq8TeX4numdzQCMTInow/videos
Website: http://www.mahor.xyz/
It seems that he will launch soon the commercial version.
I would like to see more difficult parts to 3d print with retractions, very detailed parts with lot of speed changes and classic mechanical parts with sharp angles.
This one was shown at the last Makerfaire in Roma.
They are going to launch a Kickstarter very soon.
The quality seems good especially on the small nozzle of 0.4mm, there is an additional difficulty to control with precision the extrusion flow on those big boys. This is very important for the quality of the print, especially if you want to print fast.
There is not too much detail on this one, it seems to be enclosed in an aluminium case, we just see the gear of the stepper motor on the side of the screw.
The quality of the layer and the throughput is good also with the nozzle of 1.5mm
Youtube: https://www.youtube.com/channel/UCpB7NwziKG0b56AxqeZyQUw
Website: https://www.direct3d.it/
Same story as with the previous extruder, I would like to see more difficult parts to check for retractions, control of the extrusion flow with sharp angles, very fast speed changes.
I am quiet happy to have found those projects, they are on the way to make Pellet Extruders available for any one.
