Halbach Array Linear Direct 3D Printer Extruder Drive

thingiverse

I built a lighter extruder drive for my Pusa I3 and most 3D printers use one. It's based on a 3-phase linear actuator with a magnetic Halbach array that can replace NEMA17 directly in any 3D printer. Using VCA as the drive was considered, but it's pricey and less strong than a drive with 3-phase coils and a magnetic Halbach array. https://youtu.be/aeM0KQuF120 The features of this extruder drive are: High force to weight ratio Continuous and peak forces at high levels Weight is just 4.2oz or 119 grams High accelerations A Halbach Array magnetic system Scotch Yoke mechanism. For more details on the drive, see here: http://www.instructables.com/id/Linear-Direct-3D-Printer-Extruder-Drive-Fusion-360/ Five Neodymium Rare Earth magnets are needed - they're 5X5X25mm N42 grade. Alternatively, compound magnets can be used and ten of them will do. The diameter of the wire can be changed if a larger force is required but this will increase the current consumption. Tests with a 3-phase bridge driver show that the drive effort is sufficient to operate as an extruder drive. This device is still experimental so work on it continues. Print Settings: Printer: Prusa I3 Infill: 0.15