1 Topic by brw_racing

  • brw_racing
  • Member
  • Offline
  • Registered: 2013-08-27
  • Posts: 11

Topic: Recycling filament

I was playing around again today with my filastruder and noticed the auger has enough sharpness and close enough tolerance to the pipe to shear 3mm abs if you wedge it down into the feeder hopper.

I have samples here of 3mm filament that it would be nice to recycle and make into 1.75 that i can use or even recycle 1.75 that just may not be accurate or have some defect.

My plan is to drill and tap a hole in the pipe slightly behind the hopper where filament can be fed into to be chopped by the auger and forced forward into the pipe.  If it does not work i can plug it with a bolt.
If it works i may try and design a modified servo feeding motor.

2 Reply by elmoret

  • elmoret
  • Filastruder
  • Offline
  • Registered: 2012-10-11
  • Posts: 6,048

Re: Recycling filament

Cool!

One issue you might have is keeping melt pressure up. If you only feed one or two "pellets" per rotation, your feed rate will be lower, melt pressure will be lower, and output rate will be lower.

Filastruder - the robust, inexpensive filament extruder
E3Dv6 All Metal Hotend - the premier 3D printing hotend

3 Reply by IanJohnson

  • IanJohnson
  • Moderator
  • Offline
  • Registered: 2012-08-07
  • Posts: 2,815

Re: Recycling filament

I think the idea is to chop the filament back into pellets without melting it.  I get plenty of filament that could use recycling.  It would also be useful for making masterbatch pellets by mixing colors at high concentrations, extruding, and then chopping the filament into pellets.  You would want to spin the auger a lot faster, maybe with a drill.  Also you only need an opening as large as the filament, so you could drill several holes around the pipe and feed several filaments at once.   A simple gear motor should be fine for a feeder, you can change the speed by adjusting the voltage, and adjust the speed up or down depending on the size of the pellets you see coming out.

I could see this being something that might mount on to a drill press.  Chuck the auger, slide the barrel/feeder thing over it, and clamp it to the table.

4 Reply by -luckyphil-

  • -luckyphil-
  • Member
  • Offline
  • Registered: 2013-09-18
  • Posts: 20

Re: Recycling filament

Just with the masterbatch idea...

If you are extruding the concentrated mixture you could have a fan (with flat blades) type device at the die chopping the filament as it exits.

You could increase or decrease the size of the pellets by varying the speed of the "fan".

I like the idea of the multiple input holes for recycling filament at the back while perhaps adding a small percentage of either virgin material or colourant through the hopper for mixing.

5 Reply by DDevine (edited by DDevine 2013-10-24 01:40:38)

  • DDevine
  • Member
  • Offline
  • Registered: 2013-10-03
  • Posts: 16

Re: Recycling filament

I wouldn't use the Filastruder for this, but it would be pretty easy to make some sort of drill-attachment which does the same thing... In fact, you could get an auger/drill-bit and put it in a pipe with 3 and 1.75mm holes to feed the filament in.
You could do it by hand but I guess you probably want to automate it and the sky is the limit there.

6 Reply by brw_racing

  • brw_racing
  • Member
  • Offline
  • Registered: 2013-08-27
  • Posts: 11

Re: Recycling filament

Thanks for all the comments. I can see ill need to think this out more clearly.

7 Reply by laird

  • laird
  • Member
  • Offline
  • Registered: 2013-08-28
  • Posts: 109

Re: Recycling filament

I've been thinking about this. I bet you could make a widget with a pair of counter-rotating gears with sharp teeth meeting at the points, tied to a pair of traditional gears meshing, so the two pointy gears pull the filament in and chop it up, powered by a hand drill. They'd have to be metal to work. Plus a case so you don't chop a finger instead of filament. :-)

8 Reply by elmoret

  • elmoret
  • Filastruder
  • Offline
  • Registered: 2012-10-11
  • Posts: 6,048

Re: Recycling filament

laird wrote:

I've been thinking about this. I bet you could make a widget with a pair of counter-rotating gears with sharp teeth meeting at the points, tied to a pair of traditional gears meshing, so the two pointy gears pull the filament in and chop it up, powered by a hand drill. They'd have to be metal to work. Plus a case so you don't chop a finger instead of filament. :-)

http://www.soliforum.com/post/39299/#p39299

Filastruder - the robust, inexpensive filament extruder
E3Dv6 All Metal Hotend - the premier 3D printing hotend

9 Reply by jgharris80

  • jgharris80
  • jgharris80
  • Member
  • Offline
  • Registered: 2013-10-02
  • Posts: 20

Re: Recycling filament

brw_racing wrote:

I was playing around again today with my filastruder and noticed the auger has enough sharpness and close enough tolerance to the pipe to shear 3mm abs if you wedge it down into the feeder hopper.

I have samples here of 3mm filament that it would be nice to recycle and make into 1.75 that i can use or even recycle 1.75 that just may not be accurate or have some defect.

My plan is to drill and tap a hole in the pipe slightly behind the hopper where filament can be fed into to be chopped by the auger and forced forward into the pipe.  If it does not work i can plug it with a bolt.
If it works i may try and design a modified servo feeding motor.

I like the idea of a hole in the pipe, using the shearing force , only make it a smaller version of a filastruder. Control the filament with an exstruder to get uniform pellet size.  Cheap motor to drive the auger(?) Control the exstruder with Aurduino? (programming is not my forte, but how hard could it be?) Could be handy to re-chop for masterbatch etc.

-"Simpler is better, except when complicated looks really cool."
-"As soon as you make something fool proof...along comes an idiot."
-"I have not failed.  I've just found 10,000 ways that won't work."  ~Thomas Edison

10 Reply by foofoodog

  • foofoodog
  • Member
  • Offline
  • Registered: 2013-08-16
  • Posts: 146

Re: Recycling filament

I have found that if all you are trying to do is run out a darker color to start a lighter one you can feed it twigs like a rocket stove and it will digest them. You wrap scrap in a loop around your hand, cut the loop top and bottom and put a loose bundle of sticks in the hopper. Note this might void your warranty.

11 Reply by 2n2r5

  • 2n2r5
  • 2n2r5
  • Member
  • Offline
  • From: Frederick, MD
  • Registered: 2013-05-09
  • Posts: 1,208

Re: Recycling filament

foofoodog wrote:

I have found that if all you are trying to do is run out a darker color to start a lighter one you can feed it twigs like a rocket stove and it will digest them. You wrap scrap in a loop around your hand, cut the loop top and bottom and put a loose bundle of sticks in the hopper. Note this might void your warranty.

I just tried this. I think all the spare filament came out but now I can't feed any new filament. isnt this how laywood is made?

SD3 w/ mods:
Glass bed with QU-BD heat pad upgrade, threadless ballscrew w/ 8mm smooth rod, spectra line belt replacement, lawsy MK5 extruder, Lawsy replacement carriage, E3D hotend, Ramps 1.4 w/ reprap discount controller, DRV8825 drivers, 12v 30A PS, Acrylic case, Overkill Y-idlers, Filament alarm, Extruder fan + more.

2n2r5's Website

12 Reply by foofoodog

  • foofoodog
  • Member
  • Offline
  • Registered: 2013-08-16
  • Posts: 146

Re: Recycling filament

2n2r5 wrote:

but now I can't feed any new filament.

I think you voided your warranty.

2n2r5 wrote:

isnt this how laywood is made?

Interesting thought about the laywood. So if you mixed some fine sawdust with a binder and made sticks you could stuff that in there and it might work, or it might go off like a bomb.

13 Reply by IanJohnson

  • IanJohnson
  • Moderator
  • Offline
  • Registered: 2012-08-07
  • Posts: 2,815

Re: Recycling filament

I wonder if you could do that with just about anything if the particles are small enough.  I doubt wood  has any special property that makes it more compatible with plastic.  I bet you could make coffee filament if you ground it fine enough.   Then you could make a coffee coffee cup that won't ever show coffee stains.

14 Reply by foofoodog (edited by foofoodog 2013-10-25 23:51:02)

  • foofoodog
  • Member
  • Offline
  • Registered: 2013-08-16
  • Posts: 146

Re: Recycling filament

IanJohnson wrote:

I wonder if you could do that with just about anything if the particles are small enough..

Getting way off topic now but they do have that precious metal clay that you sculpt and then fire. Never tried it but it looks neat.
Back closer to topic perhaps you could use scraps as the binder and then sinter it.

Back in my boat building days we would mix epoxy with everything from aluminum powder to silica fume to graphite dust depending on what we were going for. Maybe 50% aluminum carriages and an extruder would work.

15 Reply by laird

  • laird
  • Member
  • Offline
  • Registered: 2013-08-28
  • Posts: 109

Re: Recycling filament

elmoret wrote:
laird wrote:

I've been thinking about this. I bet you could make a widget with a pair of counter-rotating gears with sharp teeth meeting at the points, tied to a pair of traditional gears meshing, so the two pointy gears pull the filament in and chop it up, powered by a hand drill. They'd have to be metal to work. Plus a case so you don't chop a finger instead of filament. :-)

http://www.soliforum.com/post/39299/#p39299

I saw that. What I was thinking of is more like a very enthusiastic nail clipper, sufficient to snip filament into small pieces for re-extrusion.

When my RPM arrives (I can dream) perhaps I could mill the gear myself. It was easy to model in OpenSCAD, but of course a plastic gear isn't going to snip filament. :-)

Though the shredder was awesome, it's MUCH harder trying to solve the problem of shredding large prints (much less the sofa in the video).