Spring-loaded Replicator 1 Drive Block

thingiverse

This rewritten "Spring-loaded Replicator 2 Drive Block" part is compatible with MakerBot's Replicator 1 (single and dual extruder) by implementing minor adjustments. The modification list includes cutting the upper-left corner wall, changing screw hole types, trimming a piece off the cover, and decreasing the bearing bolt stub diameter. This design is based on work from Thingiverse users MakerBot, whpthomas, emmett, and whosawhatsis. The spring-loaded arm ensures consistent pressure between the drive gear and bearing to prevent filament skipping. Mirrored models fit either carriage side, with STL and STEP files available. A spring height adjustment part is provided for increased spring rate if needed. Following MakerBot's instructions (http://www.thingiverse.com/thing:53125), you need a M3 x 16mm flat head cap countersunk hex screw, M3 x 8mm flat head cap countersunk hex screw, a 3mm ID x 10mm OD x 4mm width 623ZZ bearing, and a 0.360"OD 0.276"ID 0.630"-0.900"L (9mm OD x 7mm ID x 16-22mm L) 32lbs/in spring rate compression spring. Purchase screws and bearings from a2stainless.co.uk, bearingoptions on eBay, and switchedkwb on eBay for the stepper motor and lever assembly, ensure 3mm of hex screw protrusion behind the base, leave space for lever movement, and use medium thread-lock if needed.