Extruder Knob - 5mm shaft

thingiverse

I needed a better knob than the stock one on my Rostock Max V2, by SeeMeCNC. The original slipped off the shaft and hurt my hands to turn because I don't have calluses yet. So, I quickly came up with this new design. It fits tightly on the shaft. This should fit any 5mm diameter shaft with a 0.5mm cutout for the setscrew. I updated the SCAD source with better parameterization and depth of shaft cutout, and added two improved models. Both new files (20161206) are for 6mm shafts - one for an extruder and another for a 10-position rotary switch. Print Settings: - Printer Brand: SeeMeCNC - Printer: Rostock MAX BYOE - Rafts: No - Supports: No - Resolution: Go coarse for speed - Infill: 25% Notes: - Printed in PLA. The shaft opening is tight, so you might need to slightly enlarge it to get it to fit on yours. - Material doesn't matter - go cheap. How I Designed This: I created this design in OpenSCAD. The knob handle part is an extruded 6-sided circle that has been Minkowski-summed with a small sphere to give the rounded edges. The shaft is the difference between a cylinder and two other things: one, the shaped cylinder for fitting over the shaft; and two, another rotated cylinder for the setscrew. I uploaded the source code so you can modify it to your liking. I also wanted to show how Minkowski works because it's cool. In fact, Minkowski sums come into play when computing the number of roots for a polyhedral start system when solving a multivariate system of polynomials. That's a fun fact for the day. Share & Enjoy!