Does any of you have any experience with this? I’m looking at the Felfil Evo pellet extruder which seems like an acceptable option. One thing I don’t understand. Why are the shredder and spooler so ungodly expensive?
I mean, can’t you just use an old blender to grind pieces down far enough for the pellet extruder? The finer the better no? Airborne microplastic may be a concern at some point.
Also the spooler. Is that more complicated than a stepper motor that runs at a certain RPM spinning the spool around? With perhaps a mechanism that slows down a bit after X rotations to compensate for the spool getting thicker. Nothing an Arduino can’t handle. Also don’t grip the spool that tightly so pull strength is more or less equal.
Both the spooler and shredder individually cost more than a pellet extruder does…
I have no experience with this directly, but as far as I understand the subject, you need size consistency of the input material because the melt time is important if the size is mixed, the small stuff will be different than the big stuff and make an inconsistent output. Overcooking is a bad thing. This is not a batched process, it is continuous so; mixed in = mixed out.
As far as I understand it, the spooler is pulling the material in tension and this is what sets the actual filament diameter by adding or removing a very precision amount of tension.
I would think that grinding would be the hardest part due to a combination of garbage in garbage out (you would want your grinding process to produce fairly consistent pieces) and the forces involved. My prints are largely functional and need to be strong and they would be… a massive pain to pass through a blender. You could build a massive shredder to deal with them, but I wonder if a hammer mill would be easier. In any case, you’re talking about a pretty large amount of force in play.