HICTOP Prusa i3 Extruder Mount / Lever (adjustable)

thingiverse

I had trouble with the original extruder mount provided. It was printed so that stress from the spring was transversal to the layers. The result was warping under heat from the extruder motor and a layer or two began to separate due to excessive stress. Moreover, the spring tension was overkill. I created a new mount having a thicker base to address these issues. The lever stand off has been reduced to keep the outer dimensions the same as the old. Additionally, I designed the section that the filament goes through not to interfere with the pulley on the lever. With the original, I needed to file down this region to prevent unnecessary stress. I also made a lever with an extended upper end for easy filament loading and unloading. The original was just too short to get much pressure on. This lever allows for tension adjustment as well. You will need a M3x20 socketed bolt and 3 M3 nuts to use it, however. The tension block, as labeled in the parts list, accepts a M3 nut and inserts into the lever where the M3 bolt comes from the other side. Two more M3 nuts are needed, to be tightened together on the bolt, allowing it to turn in place without coming out of the lever via spring tension. It was a bit tricky for me to tighten these from the small openings of the lever, but it was doable. Taking a couple small screwdrivers from either side and pressing on the flats of the hex nuts is what worked. A little thread lock probably wouldn't hurt either. Note that with this design, twisting the bolt counter-clockwise increases tension. I thought with a little work, maybe these parts will help somebody else who has similar issues. I added a second mount file, with a reduced thickness by 1.5mm on the spring resting wall. This shifts the spring compression length range up 1.5mm allowing for less tension if my original mount is creating still too much. Print Settings: Printer Brand: Prusa Printer: Prusa Steel Rafts: No Supports: Yes Resolution: 0.1-0.2 Infill: 100% Notes: I have only printed this in ABS. PLA would probably not work well, especially if printing in an enclosure were the extruder motor can get hot. Print in the orientations given for strength. Support material removal was an annoyance, but worth it. The tension block and nut insert may need some work to get good fitting depending on your printer. After any necessary cutting / sanding, the nut needs to be a tight fit, and the block should slide into the lever with a little friction having no play. Lastly, the tension block is not symmetrical. The extension that the spring goes over is slightly nearer one side than the other. This is the side that should face toward the mount in full assembly. If you look at the original lever, you should see what I mean.