Spring adapter for MK6+ plunger

thingiverse

The MK6+ is great, but the stock configuration assumes the filament's diameter remains constant. If the filament gets thinner, the pressure will drop off rapidly and extrusion will stop. If it gets thicker, steps will be missed, loud noises will be made, and extrusion will slow down. Either situation can cause a ruined or weakened output. I was tired of having to babysit it, and I had two extra springs in my Wade's hardware kit, so I designed this spring adapter. Before I installed it, my MK6+ would print for around 30 minutes, on average, before needing tightening or loosening. Since I've installed it, I've printed for more than eight hours without intervening. It took my machine from "high maintenance" to "fire and forget." Instructions Note: This design is for the MK6+ with 3 mm filament. I will upload one for 1.75 mm as soon as I have a chance to do it. Also, make sure the adapter is not heated up by the motor. In my case the stock fan works well for that. Print the adapter. In the recess inside the adapter, install a spring like the ones included in UltiMachine's Wade's Extruder Hardware Kit. Remove the thumbgrip from the plunger screw (or use another equivalent screw, but still with the nut on it). Bolt the adapter onto the MK6 top end, over the screw, so that the spring presses on the screw. It's much easier if there's no filament in the extruder. Adjust the screw so that it moves the plunger in further than it could if filament were present, but not all the way to the drive wheel. I used needle-nosed pliers. Thread filament under power (with the motor running). I had to cut it at an angle and use a good deal of force to get the plunger to move out of the way, but you might not have to if you are willing to adjust it more than I am. Enjoy lower-maintenance printing!