I saw a 3d printer using plastic pellets instead of filament.
Is this a good idea? Because I never saw anyone doing this.
Seller says “in this way it won’t run out of filament” but I have the impression of imprecise extrusions (machine was fitted with a big 0.8mm nozzle)
It was tried, quite extensively, early on in the reprap movement. No-one managed to get it working reliably. The issue is that the pellets don’t feed consistently enough. This means the flow is inconsistent. This massively messes with the quality of the print.
There are theoretical ways to compensate. Unfortunately, most result in a huge jump in complexity and weight on the head. Neither is a good thing.
Basically. The benefits aren’t generally with the costs, outside of a few, very niche areas. It’s also now easier to source filament most places, compared to pellets. So even that isn’t a game changer.
Pellet printing is usually used in larger printers. You can get much higher flow rates and the pellets are cheaper than filament. That’s good when your build volume is measured in cubic meters and you are using many kilograms of plastic in one print.
There are downsides as well. High throughput pellet feeding hot ends are insanely expensive. But there are practical issues as well, retraction can be really tough to dial in.
This was my first question how the hell do you do retraction???
A little vacuum pump, like a carburetor on a motorcycle from the 70’s? Hell if I know, but that’s my idea.
I mean the same way, retraction isn’t pulling the molten filament out of the nozzle in FDM so I’m either filament or peeler based extrusion you just run it in reverse briefly.
there’s this: https://greenboy3d.de
Not cheap though, and I think the first batch hasn’t shipped yet.
the main merit to me would be printing super soft materials that cant even be made into filament reliably becomes possible
Looks good, thanks for sharing! If they add Bambu support, I’ll probably buy it.
You would be giving up some feed-rate control and retraction. Probably not too bad with certain materials and large scale prints, but I’d be surprised if you could do anything moderately precise with this.
Uuuuhhh that’s why all the samples were printed in vase mode with a huge nozzle!
I didn’t think about retraction!
Well, they put my Low-Poly Rose Twist Vase in the background so it seems legit 🤷
You want to minimize wight and vibration on the printing head. And everything that deals with pellets adds a great deal of both.
In theory you can manage to melt the pellets in a static machine away from the printing head. But you will get a lot of new problems getting it where you need and switching it on and off as needed.
Pellet feeders are not meant for high speed machines. Pellet feeders are for large format machines where the speed comes from the volume of filament they can extrude while printing.
Ok. That is a very compelling use case. I guess over some size they become a non-brainier.
As with everything 3d printing, it’s a tradeoff.
It’s harder to prevent oozing, harder to change colors, worse quality(usually) and larger nozzles.
But you print much cheaper, often can print larger parts with larger nozzles (stronger).
What I do with printing, I’d seriously consider a retrofit pellet extruder on my smallish machine (e5+) If it were reasonably priced.
Almost everything I do is “structural” and doesn’t need to be pretty direct off the printer.
