It would be great if you could make your own filament. At first glance it seems simple, but as a [Thomas Sanladerer] When he found out he was a student there were a lot of details that can interfere with your design. His extruder is working, but he wouldn’t suggest redoubling your efforts. In fact, he hopes that if you try to do it yourself, you can learn what not to do.
In all fairness [Thomas] was a low budget student trying to save. For example, he tried to drive the auger with a drill. Why not? It looks like a drill. But he found that was unsatisfactory and switched to a pair of wiper motors with a built-in gear train.
The wiper motors allowed him to get some ABS filament, but the machine had more problems. Further findings were to keep the water cooling tank closed so that water does not splash on the electronics and it is difficult to view the filament with a CCD sensor.
The controller is a simple Arduino. There are three heat zones before the plastic reaches the die. As you would expect, there is a PID controller to control the machine.
[Thomas] says the flow rate was too high so slowing production may have helped. A smaller snail is also on his list of things that he would do differently in retrospect. The melting area needed a thermal break, much like the hot end on a 3D printer, to keep hot plastic from creeping up and plugging towards the cooler part of the pipe.
With his current experience and a larger budget, we have no doubt that he could have a working extruder. As it is, we always like to learn from other people’s sub-optimal builds. It is a little humbling to show you failed projects on the internet, but it is a valuable service indeed.
We want an extruder that can recycle our garbage parts. We’ve seen some really cheap builds, but we don’t really know how well they work.