Here’s a great low cost filament extruder solution. It uses basic parts available from any hardware store, and a few 3D printed ones — estimated cost is well under $100.
It’s very similar to the Lyman Filament Extruder, but can be built for even less money. By using 200C set-point heaters, his setup requires absolutely no electronics — although a cheap PID controller from China could give him more extrusion capabilities with temperature control… Regardless, the system appears to make good filament and he uses it exclusively for his personal filament consumption in his Delta printer. He’s even hacked up the ABS casing of a refrigerator, ground it down, and turned it into filament using this machine! If you’re hungry for more details, the full build log and discussion can be found on the RepRap forums.
He also has a guide on making your own ABS color masterbatch to make your own filament colors!
As [Mic] often got requests to make high-power switching boards, he recently finally gave in and designed the one shown above based around a solid-state relay. Some of our readers that already play with mains power know that switching should normally occur when the voltage crosses zero volts. The ‘TRIAC BLOC’ is able to do so, which also allows mains frequency measurement. [Mic] then tuned to the internal oscillator of his ATtiny microcontroller with this 50Hz by adjusting its OSCCAL register value, so the switching command can be sent at the ideal moment. Zero crossing detection is implemented by feeding the mains into an AC optocoupler. [Mic] discovered that the optocoupler diodes are not identical, so he had to adjust his firmware to account for the time differences.
All the resources are available on github, we would be interested to hear your detailed analysis of the circuit implemented with the passives R3/C1/L1/R8/C3.