(2) 1″ diameter 300W Heater Bands

Sourcing Notes These are the ones I used, Amazon seems to be out of stock. You can also take the band-heater element out of most “crockpot” style warmers, and wrap it around the barrel. The PID will take care of the rest. Est. Cost New $4.49/ea Amazon...

(1) Char-Broil Propane Turkey Fryer

Sourcing Notes Found mine for $10 at Goodwill. The fryer adds structure to hold the charcoal, keeps heat focused on the keg, while also giving you decent low-temp control. Comes set up with a propane burner that can be used to retort the syngas for making biochar....

(1) 4:1 Planetary Geared NEMA24 Stepper Motor

Sourcing Notes This is the most expensive part of the extruder, but it’s the best way I’ve found to get sufficient torque for extrusion AND precise computer control. Open to suggestions and improvements, but this works. Est. Cost New $86.00 Amazon...

(1) Lava-Style patio heater

Sourcing Notes The glass tubes on these particular heaters tend to break, check craigslist for used cheap ones before buying new. Est. Cost New $199.99 Amazon...