Spring Enhancer/Compressor Upgrade for Minimalistic Mk8 replacement

thingiverse

This "Enhancer" boosts the force your existing spring applies onto the filament, making for more consistent feeding. It's a straightforward addition to your existing "MK8 Replacement." Thingiverse members initially suggested buying a compression spring from McMaster-Carr (part # 9657K311): http://www.mcmaster.com/#9657k331/=v4n93e. However, I noticed the spring wasn't applying enough force, and too much force was getting wasted in the bend it made due to its angle with the arm. Since force applied by a spring is directly proportional to how compressed it is, I created this little add-on to achieve two things: Shortening the distance between the base and arm of the "Minimalistic MK8 Replacement" compresses the spring more, and aligning the spring with the lever arm so it doesn't bend. Instructions are provided below. I printed this using MakerWare's standard resolution preset for PLA: 10% infill, two shells, a layer height of 0.20mm, supports turned on, and no rafts. You can print however you like; I prefer 230C filament with a 40C build plate temperature. To ensure successful printing, you must turn on support since there is an overhang. For the Replicator Dual, I recommend my "Extruder Block" which allows the arms of the "Minimalistic MK8 Extruder" to move freely without being obstructed by the top plate: http://www.thingiverse.com/thing:607712