Small Axial Flux Alternator (6 coils, 3 phases)

thingiverse

Here is my design for an encapsulated mini axial flux alternator perfect for tiny wind or water turbines. It produces over 12 volts when manually turned and I have proven that it works quite well with further detailed analysis still pending. Initially, smaller magnets were utilized but they weren't delivering as desired; however, the use of the 20x10x2mm N52 ones greatly improves performance for this purpose. The design comes complete with a 3D-printable coil former for winding the six coils in addition to being able to attach it to a continuous rotation servo or power tool and integrate a mechanical or electrical counter. I have also put together a quick Arduino-based counter paired with a reflective distance sensor that is easily visible from the provided pictures. Building this alternator motivated me to develop an automated winding machine that effortlessly guides the wire, which proved to be a massive undertaking; however, more details on this project can be expected in the future through my blog. I genuinely hope you find this alternator to be useful. https://www.youtube.com/watch?v=nuLBbzx3v4c&feature=youtu.be Instructions What is needed besides printed parts: 1- Stainless steel M4 rod, approximately 80mm long for use as the axis. 2- 4 x 60mm M4 bolts and nuts to assemble the enclosure securely. 3- 2x hex nuts on each side of the magnetic rotor flywheel for fixation purposes. 4- 2 x self-fixing nuts that securely fasten the flywheels onto the axis. 5- 2x MR84 ZZ, 4x8x3 mm Ball Bearings for stator shell front as well as back to ensure smooth rotation. 6- hot glue or silicone for sealing the enclosure completely and preventing leakage. 7- approximately 300 meters of 0.15mm copper wire coated with enamel for coil production. 8- sixteen N52 neodymium magnets, 20x10x2mm each for flywheel construction (found at http://www.magnetportal.de/quader/neodym-magnet-quader-n52-20x10x2mm-13-6kg/a-92/). 9- Electrical tape for temporary attachment of the coil windings during creation. 10- six Schottky rectifier diodes, model number 1N5819 each, used in the three-phase rectifier setup. 11- a single 470µF capacitor with a 25V rating or higher to ensure clean generation current flow. 12- epoxy resin to encase the stator coils and wires securely after winding. Additional tools needed for coil winder: 1- Approximately 40mm long countersunk M3 bolt equipped with several hex nuts and washers. 2- continuous rotation servo paired with a robotic arm 3- mechanical or digital counter used to accurately measure windings. 4- ... Briefly, my instructions lack clarity concerning the coil winding part, particularly as I have built an automated machine dedicated for that purpose; a blog post about it is yet to come. It's essential to note the importance of wiring the coils in "star" configuration and having them complete with 700 windings each. As for the flywheels, arranging magnets in alternation order (N-S sequence) while securing them using super glue ensures optimal performance; ensuring correct order can be a bit tricky but doable. Be cautious not to remove these tightly fitting magnets once in place because doing so will result in complications. All of my printed parts were created with black PLA material, which necessitates careful processing afterwards. It is necessary to fine-tune the coil former slightly by hand to achieve the perfect shape and make it free from any bumps. Since this process can get somewhat cumbersome due to the thin wire's properties, one might want to take care of it immediately. To wind your coils successfully using electrical tape is crucial, thus you have two options; first use super glue if needed and apply slim strips through coil former slots afterwards, then wind zip ties over all of them, ensuring proper coil shape retention while leaving sufficient room. This way is preferred for efficiency purposes and minimizes any inconvenience related to usage later on.