1 (edited by elmoret 2013-03-25 23:16:29)

Topic: Filament Extruder - Convert pellets to filament

So, like most people, I've been surprised at how much filament costs, compared to raw plastic. For example, 2kg of Makerbot plastic is $110 shipped, but 1kg of raw ABS is $15 shipped. As some of you probably know, this has been identified by others as a problem too. Desktop Factory has put out an offer of $40,000+ prizes for anyone that comes up with a machine that converts pellets to filament.

http://desktopfactory2012.istart.org

Clearly, I am not alone in my desire to use ABS pellets! So, I set out to build a machine to convert these pellets to filament. Here's what I came up with:

https://dl.dropbox.com/u/1786359/Photo%20Nov%2015%2C%205%2017%2050%20PMa.jpg
https://dl.dropbox.com/u/1786359/Photo%20Nov%2015%2C%205%2002%2020%20PMa.jpg

Right now, I extrude at about 10 inches per minute, though that can be sped up. I'm kinda taking things easy for now and learning about it. The total power draw is about 40 watts, and at 10 inches/minute, with 1.75mm filament, I'm looking at about 24 hours to extrude 1kg. So, 1kg works out to about 1kwh of electricity, or 12 cents where I live. Not bad! I'm extruding at roughly 185degC. This is a little harder on the motor than a higher temperature, but it's all I can get to right now. I need a higher power heater, something more like 60 watts.

I was concerned that the filament would not be consistent. I measured the first 4 feet at 6 inch intervals with a caliper. Here's what I found:

1.8mm
1.76mm
1.8mm
1.78mm
1.76mm
1.79mm
1.77mm
1.79mm

Which works out to 1.78 +/- 0.02mm. Here's some of the filament I made:

https://dl.dropbox.com/u/1786359/Photo%20Nov%2015%2C%208%2018%2003%20PMa.jpg

I haven't tried printing with it yet, but I don't think it'd be a problem.

What do you guys think? Open to feedback or comments! I'm pretty excited about this, can't wait to play with it some more!

I'm thinking about selling kits or assembled extruders. Would anyone here be interested?

2

Re: Filament Extruder - Convert pellets to filament

I'd be more interested in your process and cost of build.

I too have noticed the giant discrepancy between cost of filament and cost of pellets, especially in basic colors i'd love to be able to either be able to mix my own colors or just extrude it at a lower cost!  Because then it comes to a matter of how much filament do I need to extrude to recoup the cost of the extruder.

3 (edited by jooshs 2012-11-16 02:38:02)

Re: Filament Extruder - Convert pellets to filament

I have to imagine most people would be interested in a kit or build manual with bom if it extrudes well. The tolerance in diameter is definitely crucial, but I would say the consistency of extrusion when printing has to be great for it to be worthwhile. Please post some pics of prints at .1 mm with this filament if you get time. That will be the real selling point!  Looking promising though...  Any estimate on total cost of the system?

4

Re: Filament Extruder - Convert pellets to filament

Around $200 in parts. No machining/welding needed.

5

Re: Filament Extruder - Convert pellets to filament

The machining and welding have been the sticking points for the other kits.  It will be interesting to see how this one works out.

6

Re: Filament Extruder - Convert pellets to filament

Great effort. I look forward to seeing it refined a bit. The proof of concept is undeniable.

7

Re: Filament Extruder - Convert pellets to filament

jooshs wrote:

I have to imagine most people would be interested in a kit or build manual with bom if it extrudes well. The tolerance in diameter is definitely crucial, but I would say the consistency of extrusion when printing has to be great for it to be worthwhile. Please post some pics of prints at .1 mm with this filament if you get time. That will be the real selling point!  Looking promising though...  Any estimate on total cost of the system?

Unfortunately, Solidoodle still has not shipped me a replacement bracket or threaded rod, so anything I print will not look too great, regardless of filament.

I'm happy to send you some if you want to test it out, though.

8

Re: Filament Extruder - Convert pellets to filament

What a great project!
What about air bubbles, is this then consistent?

Solidoodle 2 - Repetier Host V0.82 - Slic3r 0.9.7

9

Re: Filament Extruder - Convert pellets to filament

RSandven wrote:

What a great project!
What about air bubbles, is this then consistent?

I only printed about 30 feet before shutting it down for the night, but I did not see any air bubbles. I'd have to run it longer to know for sure.

10

Re: Filament Extruder - Convert pellets to filament

IanJohnson wrote:

The machining and welding have been the sticking points for the other kits.  It will be interesting to see how this one works out.

What other kits are you aware of? It'd be interesting to see what others have come up with.

I've run through $120 of ABS in a month personally, so this is huge for me. Actually I need some empty spools, not sure where to get those.

11

Re: Filament Extruder - Convert pellets to filament

Check out the Lyman's filament extruder at Thingiverse, and its derivative.  I think there have been a couple of Kickstarters in the past as well.

12

Re: Filament Extruder - Convert pellets to filament

No air bubbles is good. Looking forward to follow this smile

Solidoodle 2 - Repetier Host V0.82 - Slic3r 0.9.7

13

Re: Filament Extruder - Convert pellets to filament

elmoret wrote:
jooshs wrote:

I have to imagine most people would be interested in a kit or build manual with bom if it extrudes well. The tolerance in diameter is definitely crucial, but I would say the consistency of extrusion when printing has to be great for it to be worthwhile. Please post some pics of prints at .1 mm with this filament if you get time. That will be the real selling point!  Looking promising though...  Any estimate on total cost of the system?

Unfortunately, Solidoodle still has not shipped me a replacement bracket or threaded rod, so anything I print will not look too great, regardless of filament.

I'm happy to send you some if you want to test it out, though.


I'd love to try some...  For $200, you could count me in if it prints well!

14

Re: Filament Extruder - Convert pellets to filament

Very nice, would like one myself when I get my printer.

SD2, Glass Bed, Fan on control board, Simplify 3D, Workbench(on order).

15 (edited by elmoret 2012-11-17 18:49:33)

Re: Filament Extruder - Convert pellets to filament

https://dl.dropbox.com/u/1786359/Photo%20Nov%2016%2C%203%2056%2005%20PMa.jpg

Printed at 0.3mm. Black is from Amazon, white is from my garage. Bad banding on both, thanks to z-axis.

I printed the black first, so there's some streaks of black in the white print.

16

Re: Filament Extruder - Convert pellets to filament

Looks pretty good, could you feasibly mix colored pellets to create a custom color or would it be too inconsistent?

17

Re: Filament Extruder - Convert pellets to filament

Elmoret, I have another idea that you may want to consider. if it's feasible.

Seems you can purchase 1kg of 3.0mm white filament from repraper.  The issue is the quality and bubbles from my understanding. 

Would it be feasible and/or simpler to run 3.0mm filament into one end and extrude it down to 1.75mm while removing the bubbles and therefore increasing the quality?  Would that make the equipment / kit less expensive? 

Forgive me if my question is naive.  I was starting to shop at http://www.3ders.org/pricecompare/?o=Priceperkg and when I saw the price per kg of the repraper stuff I thought it may be easier than pellets.  Just a thought.

18

Re: Filament Extruder - Convert pellets to filament

The problem there is the repraper stuff is contaminated with stuff like ball bearing, and that after shipping, you might as well just buy 1.75mm filament

ABS pellets are roughly $7/kg, including shipping.

And don't apologize for suggesting ideas! It's how this hobby moves forward.

19

Re: Filament Extruder - Convert pellets to filament

Is that a screw based system? if so, how did you make/where did you buy the screw?

20

Re: Filament Extruder - Convert pellets to filament

elmoret wrote:
IanJohnson wrote:

The machining and welding have been the sticking points for the other kits.  It will be interesting to see how this one works out.

What other kits are you aware of? It'd be interesting to see what others have come up with.

I've run through $120 of ABS in a month personally, so this is huge for me. Actually I need some empty spools, not sure where to get those.

I've just put up STL files for printing spools smile

http://www.soliforum.com/topic/589/fila … oolsreels/

21

Re: Filament Extruder - Convert pellets to filament

Here's another comparison of prints - the hopper for the extruder. Green is from a professional filament supplier, white is from my extruder. Printing at .3mm, still waiting on replacement parts from SD.

https://dl.dropbox.com/u/1786359/Photo%20Nov%2028%2C%2011%2026%2055%20AM.jpg

And here's the extruder, getting closer to a finished product. Still need to print the filament guide/fan mount.

https://dl.dropbox.com/u/1786359/Photo%20Nov%2028%2C%2011%2054%2013%20PM.jpg

I've run about 1kg of plastic through it so far.

22

Re: Filament Extruder - Convert pellets to filament

Pretty sweet. Did your 24hr/kg estimation hold up?

23

Re: Filament Extruder - Convert pellets to filament

nickythegreek wrote:

Pretty sweet. Did your 24hr/kg estimation hold up?

Yup, that's about right. I did half a pound in 6 hours. I haven't run it more than that continuously.

24

Re: Filament Extruder - Convert pellets to filament

How often do you need to show up to reload the hopper?

25

Re: Filament Extruder - Convert pellets to filament

Good work man, i had a similar idea to mount the motor like that!
Can we expect a buildlog from you perhaps? Really want to make one of these too!