MK7 Extruder Drive

thingiverse

This extruder is a revamped version based on : http://www.thingiverse.com/thing:13727. The drive lever hole has been lengthened to keep the threads of the 3mm socketcap bolt from obstructing the lever. Both parts have undergone thickening in the revised areas to prevent warping. The extruder drive shown was printed in ABS at a layer height of 0.1mm on a heated bed and is installed on a Hadron Bot frame, operating reliably with this re-design. This drive utilizes the makerbot mk7 filament feed gear. For those experiencing problems with PLA jamming with metal heatbreaks, apply a small amount of vegetable oil and smear it onto the filament. This will season and coat the steel inside your heat break, creating a more slippery surface that resolves the issue altogether. Use high-quality filament with consistent diameter tolerance to minimize the risk of jams. Install a reliable cooling fan to cool the hot end heat sink and recalibrate your hotend PID settings to prevent temperature fluctuations. Instructions: Disconnect the supports from the drive and lever parts. Mount a 623 bearing into the lever using three 10mm countersunk screws. Press fit a 3mm nut into the hexagonal depression of the drive part. Insert a 3mm socketcap bolt and attach it with a stiff spring. The length of your bolt will depend on the spring's tension and the lever's size. The drive attaches to a Nema 17 stepper motor using two M3, 15mm countersunk cap bolts.