This project was developed by students from 12th of a vocational Course of Computer Maintenance at EPFelgueiras (Portugal), as part of PAP project under my orientation. The goal was to build an electric bike under European legal rools but with a good performance and autonomy that could be used daily in a frequent up and downhill area, not realy appellative for bikes uses. Half year after, dinabike as over 2600 Km (1600 Miles) with no problems at all, except for regular maintenance: brakes, tires and a few tunings.
Step 1: Stator Windings
We began by the stator building a gadget to do the copper winding.
For a correct placement of the coils we designed and cut with a computerized milling cutter a polyester mold as shown in the picture.
Step 2: Rotor Build
2 x 12 neodymium block Magnets Q-30-10-05-N42
18 cm diameter aluminum disc for magnets support
Epoxy for instant glue the magnets in aluminum discs
18 cm diameter polyester mold disc for a correct magnet position (made in CNC cutter)
Step 3: Axys Build and Mount
For a correct system to function we have implemented a double pair of spheres side by side underneath the rotors. As i said before, today i will use bearings because the mounting with spheres is not so easy. You have always to be aware not to lose any sphere in a moment where you have to grip the rotors by attempts, leaving the minimum space between rotors and stator. This is fixed in the middle of the axys. Afterwards, you assemble one side, giving the needed grip. Next you have to tight by attempts because the magnet doesn't leave space to use a tool to attach the nuts even if it was on plastic, there's no space. Interior nuts have to be tight before mounting the rotor.
Unfortunately we don't have any pictures of that assembly.
Step 4: The Tilt Controller
Step 5: Summary
Many things were left unsaid, but I hope to answer all the questions raised by those who are interested on the subject.
For finish I leave some more pictures...