Nice. Looks just like the little brother of a granulator at a recycling plant I've been to. If you want to do continuous production, I would recommend a 3d-printed rotary airlock, or maybe a screw feeder based on an auger bit.
Thanks. Did you have a look inside of the granulator? Just for curiosity. The ones I know don't create plastic powder but pellets. Continuous production isn't the big target, but at least some sort of pellet feeding mechanism is on my list of things to implement.
@@HomoFaciens If you look up "Herbold granulator" on google images, you'll get a pretty good idea of what was inside there. The one that I saw was turning LDPE flakes (I think from shredded bottles) from 10-20mm into about 4mm size. They were then blending them with HDPE and loading into bulk bags for shipping . They weren't making pellets at this plant. If they were making pellets it would basically go through an extruder with a rotating cutter on the end.
Thanks for pointing to the "Herbold granulator". These machines are obviously cutting, not grinding the plastic. You won't get the tiny grains I need with those cutters. But good to have learned about another technology for recycling plastics. Yes, I had the pellet extruders with the rotating cutter in mind.
Well, I am more interested in projects that are not made fancy because of their colors. Different materials for more than one extruder makes more sense to me. But my machines are open source, so it is your turn to bring CMYKW to direct 3D printing ;-)
No. With just a little water, the grains will stick to the walls. With lots of water you have to filter and dry afterwards. If any water at all, then on the outside as water cooling system.
i dont know , the motor will burn out if its not under load , and 140 W is alot to break down pellets of pla, have you tried a meat grinder ? the one with the screw that makes sausage , the screw will trap the particles and smash the pellets against the wall , the challenge will be that it will gum up (maybe) maybe you could do something with an old screw type meat grinder
Yes, meat or coffee grinders are common, but you will have to modify them heavily to get the desired particle size as they don't work for plastic pellets out of the box. Increasing the efficiency is the next step - stay tuned!
It is that word "may" that you have to turn into "will for sure" by your own experiments to convince me to buy a flour mill instead of improving my design ;-)
I don't think a meat grinder is appropriate for the material at room temperature. Even if you could supply enough torque (and the grinder could survive the torque), I'd expect the plate might clog. Don't know though. The man may be using a router and a peanut can, but he's implementing a simplified hammer mill -- albeit without free hammers. In my opinion, this underlying concept would be a better tool for pulverizing and grading a relatively tough granular material like PLA. He's already on the right road. A well-balanced (and safe) rotor with free hammers might be a hard thing to implement with such simple methods though. I'm sure there are all sorts of mechanical driveline parts with internal splines which would make a good stator though. Perhaps the outer ring from a synchromesh? It'll already be hardened, too. Might not be quite the HomoFaciens style though. :)
@HammyJamPants thanks for sharing your thoughts! I have been working with hammer and ball mills a couple of years ago, but to get glass powder in the range of 1µm. I don't think that kind of mills is best for getting PLA powder at room temperature. Nitrogen cooling always works, but is no option for hobbyists ;-) As I will show in the coming video, this first prototype is more of a hammer mill than I wanted it to be, just because of a lack of sturdiness. The stator screws as well as the rotor deflect when the pellets are hit. Because of that, this mill/grinder doesn't manage to smash grains smaller than about 2mm. I am currently creating a smaller and more solid version. I am also testing a self made "cutting tool" which also works more like a hammer, but one that doesn't deflect. Stay tuned to see if that works! ...and if my mill won't work I might cannibalize one of my 2CV gearboxes :)
@@HomoFaciens :) i think that less parts will be floating around because they will hit on the nuts and return faster to the lower height where the blade is (two nuts are for to hold on through the vibrations )
@@HomoFaciens i didnt understood that the temperature was so critical . and you did put a fan as the only accessory with the bag for the device to work :/ i wouldnt suggest to use frozen plastic ,as something that you probably already thought off
very cool project! thank you for making this video!
Micro-plast.
You should probably design some highly effective air-filtering for this thing :)
No need for a filter system as the final version of this grinder will be sealed, so not dust can escape and it all will end up in the bag.
Nice. Looks just like the little brother of a granulator at a recycling plant I've been to. If you want to do continuous production, I would recommend a 3d-printed rotary airlock, or maybe a screw feeder based on an auger bit.
Thanks. Did you have a look inside of the granulator? Just for curiosity. The ones I know don't create plastic powder but pellets.
Continuous production isn't the big target, but at least some sort of pellet feeding mechanism is on my list of things to implement.
@@HomoFaciens
If you look up "Herbold granulator" on google images, you'll get a pretty good idea of what was inside there.
The one that I saw was turning LDPE flakes (I think from shredded bottles) from 10-20mm into about 4mm size. They were then blending them with HDPE and loading into bulk bags for shipping . They weren't making pellets at this plant.
If they were making pellets it would basically go through an extruder with a rotating cutter on the end.
Thanks for pointing to the "Herbold granulator". These machines are obviously cutting, not grinding the plastic. You won't get the tiny grains I need with those cutters. But good to have learned about another technology for recycling plastics.
Yes, I had the pellet extruders with the rotating cutter in mind.
Great video!
Next make CMYKW colors and use 5 augers to push powder into a nozzle.
Well, I am more interested in projects that are not made fancy because of their colors. Different materials for more than one extruder makes more sense to me. But my machines are open source, so it is your turn to bring CMYKW to direct 3D printing ;-)
Very cool, and a little terrifying 😁
Yes, unplug the router before fiddling insides the can!
Try adding a little water.
No. With just a little water, the grains will stick to the walls. With lots of water you have to filter and dry afterwards. If any water at all, then on the outside as water cooling system.
i dont know , the motor will burn out if its not under load , and 140 W is alot to break down pellets of pla,
have you tried a meat grinder ? the one with the screw that makes sausage , the screw will trap the particles and smash the pellets against the wall , the challenge will be that it will gum up (maybe)
maybe you could do something with an old screw type meat grinder
Yes, meat or coffee grinders are common, but you will have to modify them heavily to get the desired particle size as they don't work for plastic pellets out of the box.
Increasing the efficiency is the next step - stay tuned!
or a plate type flour mill may work well
It is that word "may" that you have to turn into "will for sure" by your own experiments to convince me to buy a flour mill instead of improving my design ;-)
I don't think a meat grinder is appropriate for the material at room temperature. Even if you could supply enough torque (and the grinder could survive the torque), I'd expect the plate might clog. Don't know though.
The man may be using a router and a peanut can, but he's implementing a simplified hammer mill -- albeit without free hammers. In my opinion, this underlying concept would be a better tool for pulverizing and grading a relatively tough granular material like PLA. He's already on the right road. A well-balanced (and safe) rotor with free hammers might be a hard thing to implement with such simple methods though. I'm sure there are all sorts of mechanical driveline parts with internal splines which would make a good stator though. Perhaps the outer ring from a synchromesh? It'll already be hardened, too. Might not be quite the HomoFaciens style though. :)
@HammyJamPants thanks for sharing your thoughts!
I have been working with hammer and ball mills a couple of years ago, but to get glass powder in the range of 1µm. I don't think that kind of mills is best for getting PLA powder at room temperature. Nitrogen cooling always works, but is no option for hobbyists ;-)
As I will show in the coming video, this first prototype is more of a hammer mill than I wanted it to be, just because of a lack of sturdiness. The stator screws as well as the rotor deflect when the pellets are hit. Because of that, this mill/grinder doesn't manage to smash grains smaller than about 2mm.
I am currently creating a smaller and more solid version. I am also testing a self made "cutting tool" which also works more like a hammer, but one that doesn't deflect. Stay tuned to see if that works!
...and if my mill won't work I might cannibalize one of my 2CV gearboxes :)
what if you put a nut or two on the screws on a height above where the blade ends ?
What do you think would happen? Trying out things without a masterplan is usually a total waste of time.
@@HomoFaciens :) i think that less parts will be floating around because they will hit on the nuts and return faster to the lower height where the blade is (two nuts are for to hold on through the vibrations )
That floating around is a wanted effect as this cools the particles before they are hit by the blade again.
@@HomoFaciens i didnt understood that the temperature was so critical . and you did put a fan as the only accessory with the bag for the device to work :/
i wouldnt suggest to use frozen plastic ,as something that you probably already thought off
Yes, it is obvious that the cooler the plastic, the more brittle it becomes. Getting it to work at room temperature is the trick.
Coffee grinder
...to grind coffee, not PLA pellets.