RepRap Pro Ormerod Spring-loaded extruder

thingiverse

To overcome inconsistencies in filament diameters, I devised an extruder block featuring a tensioning spring. It employs a 3mm screw, nut, and tension string on a long lever arm. This solution handles variable filament sizes effectively, smoothes out action for printed gears, and simplifies hobbed insert cleaning. The spring is sourced from strong action ball-point pen; however, discussion on RepRap forums suggests using soap dispenser plunger springs instead. STEP files are available for customization. A PTFE version exists, featuring a wider feed pipe to decrease filament resistance and reduce extruder wear. Instructions include printing 'motor,' 'feeder,' and optional 'tongue' parts, followed by assembling the extruder per original RepRap plans and tensioning the spring with filament.