Direct Drive Pastruder

thingiverse

This is a simple belt-driven syringe extruder for non-Newtonian materials such as peanut butter. It utilizes a 100oz-in stepper motor from the MakerBot MK6 to provide force and applies pressure via a belt-based reduction for mechanical advantage, potentially increasing flow resolution. Co-designed with Scott Beibin in July 2012 for the Groucho Fractal Show (www.grouchofractal.com), this model was created using scraps. Note that SCAD modification may be needed for a tight syringe fit, and it relies on thing:19758 and MCAD from https://github.com/elmom/MCAD. Required parts include a high-torque stepper motor (e.g., from Anaheim Automation), four M3x10 bolts for motor mounting, a 20mL syringe with a 20mm OD, an M8 ID 26mm OD "skate" bearing, a large 5mm ID 16mm OD GT2 pulley, 300mm of GT2 belt, an M4x15 to mount a 4mm ID 16mm OD bearing, and two M1x20 bolts for clamp mounting. Assembly is easy, with the pulley attached to the motor, followed by motor bolt-mounting on the main block, belt clamping, idler bolt-mounting, belt routing through the pulley/idler, syringe and plunger pusher mounting on top, and keeping the belt under slight tension. Mounting to a printer is not included in the design. Slic3r settings should indicate a 2mm nozzle and 16mm filament for printing, with reversal disabled to prevent pusher detachment.