slotted wheel

youmagine

The wheel has 32 slots, each 80 mm in diameter, and a hole for an 5 mm shaft secured with an M3 setscrew. The beveled vanes give it a knife-edge feel rather than a simple 90-degree slot edge. All dimensions and specifications are adjustable within the OpenSCAD file. I chose this size for its uniqueness but you might prefer a smaller model depending on your needs. Measuring the timings of this wheel in motion using an opto-interrupter circuit shows that the total variation in slot width is approximately 0.2 mm, or 5% of the 4mm slot width, with my Ultimaker 2 printer. I remixed the original "open-source chopper wheel" design by jpearce, found at thing:28121.