#### 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:

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:

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?