Steve Graber, who built Kevin Caron’s 8-foot-tall Cerberus 3D Gigante 3D printer, joins Kevin Caron to finish installing and calibrating a new extruder.

STEP 1: CONFIRM THAT THE PATH THROUGH THE EXTRUDER TO THE HOTEND IS CLEAR.
Steve Graber sharpens a piece of filament and makes sure it goes through smoothly to the hotend. He and Kevin Caron also discuss whether this particular extruder has a bowden tube and how the hole itself is 3 milimeter, like the filament.

STEP 2: CHECK WIRES AND FAN
They want to test the motor and fan. That means bringing everything up to temperature because it won’t extrude otherwise.

Steve Graber and Kevin Caron also check the fan because they want the fan running before they have filament running through.

WHY THEY ARE REPLACING THE EXTRUDER
As they wait for the hotend to heat up Steve Graber explains why they are replacing the hotend. The original extruder wasn’t strong enough because, when his company first started building the Gigante 3D printer, extruder technology for this size of machine didn’t exist. So they just invented something that worked but was very slow. Now companies are designing commercial products, so they’re spending a lot more engineering time and resources and this Bondtech QR 3D printing extruder is better than what was originally included. Ideally, the 3D printer will now print faster and more precisely.

WHAT DOES THE EXTRUDER DO?
Steve Graber likens the process to what happens with a hot glue gun. You insert a stick of glue, heat it until it is molten, then squeeze the trigger. The trigger forces the hot glue through the little nozzle. With this 3D printer, instead of squeezing a trigger, a little motor with gears grabs the filament and shoves it down into the hotend.

STEP 3: CHECK EXTRUDER DIRECTION
Next they check to make sure the extruder is running the right way – last time it was running backward, and this 1 might, too. The extruder isn’t turning at all, though, and it’s making an odd noise.

STEP 4: ADJUST PRINTHEAD Z-HEIGHT
Steve Graber and Kevin Caron raise and lower the printhead to adjust its proximity to the bed. It needs to be close but not too close. When numbers get reversed in the Duet Web Control, a Web-based software for controlling the 3D print, disaster strikes. So does the printhead, which crashes into the printbed, breaking the welds on the metal print platform. At the end of video 1 Kevin Caron takes the print platform back to his metalworking studio where he repairs it.

Before you watch the second video you might want to stick around for another moment to see Kevin Caron forget the “what” ….

In the second video watch the rest of Steve Graber and Kevin Caron’s adventures in programming the new extruder at https://youtu.be/3-WRFmivMm0