A few weeks ago, I successfully updated the motherboard firmware, as well as the extruder board's firmware, so this got me pretty motivated. My main obstacle right now is the MK4 Plastruder. This part of the printer feeds plastic filament into a heating chamber, which melts the plastic into liquid form. As more filament is fed into the heating chamber, the molten plastic is pushed out of a tiny nozzle onto a build platform. My MK4 has problems feeding the filament into the heating chamber. The standard MK4 design has an aluminum toothed pulley (attached to a motor) and an idler wheel to grip and guide the filament. The idler wheel is supposed to push the filament against the pulley so that the pulley teeth can grip and feed the plastic to the heating chamber.
Two problems here:
- The pulley teeth do not grip the plastic well.
- It's nearly impossible to get the idler wheel pressed firmly enough against the filament for it to feed properly.
For the second problem, I disassembled the plastruder and cut notches across the surface of the idler wheel (much like the teeth of a pulley) with a hack saw, to help the wheel grip the filament. I put everything back together (still using the original toothed pulley) and tried it out. It worked, sort of. I had to hold the idler wheel against the filament to get it to feed, but it was performing better than it ever had. No matter what I tried, I could not tighten the idle wheel bolt in a position that gripped the filament and didn't require me to push on it.
After brainstorming with my friend with the RepRap, we realized I need a better way to hold the wheel against the filament instead of relying on the axle bolt. I came up with a bracket I'm calling the Plastruder Jack. Here's a preview photo. I'll continue this post later.