These pages will describe the build process.
On with the show... It's time to cast the magnet rotors in resin. This is a very simple mold to make.
I started by cutting a 10.5" hole in a piece of thick plywood to form the outer edge of the mold. I then cut a 5.75" circle to form the inner edge of the mold. This inner circle leaves a void to allow room for the rotating studs of the hub. The last part of the mold is just a flat piece of board that forms the bottom. The plywood pieces were sanded, varnished, and given a coating of vasaline. The outer part of the mold was then screwed to the bottom board, and the magnet rotor placed inside. I used some small plastic spacers to centre the rotor inside the mold. Then the inner part of the mold was centred and screwed in place.
Next, I mixed up some resin and talcum powder and poured it in. Easy peasy... After about an hour it was ready to remove from the mold. It came out very easliy and looked pretty good. There were high spots over the magnets. I assumed this was due to the thicker resin in between the magnets contracting more during cooling. I sanded the worst off the high spots, being careful not to remove too much resin over the magnets. I started the second magnet rotor straight away, and while I waited for that to set, I fixed the first magnet rotor to the machine.
I have actually made some more progress, but I havn't taken any photo's yet. So another update will be coming real soon, once I get some pictures sorted out.
The pictures are ready, so here's the next update....
Both of the magnet disks, and the stator are now on the machine. The stator wiring is all connected (star), and terminated to a terminal block on the back of one of the stator bracket arms. For the time being, the wiring setup is temporary and will be re-done when the machine gets installed permanently. This setup will allow me to run the turbine for a week or so, to collect some data and to workout any mechanical problems etc, that may arise... I already have a couple of things in mind that I'd like to change, but these will have to wait untill the test period is over.
The airgap from the front mag rotor to the rear mag rotor is quite large at the moment. This is because I plan to start testing at 12V cut-in voltage. As it stands, the machine reaches 12V at 110 RPM. I feel this is a little on the low side for a TSR 7 blade, but as I'm running the tests with the "unknown" basic blades mentioned earlier in the build, 110 RPM will do fine. I should be able to close the air gap and reach 24V at a reasonable RPM too. That will have to wait a while though, as I only have one 12V battery for test charging.
A 40A trip switch. This is wired up backwards and acts as the main rotor brake. With the trip in the "off" position, it allows the turbine to spin and charge the battery. When in the "on" position it creates a short circuit on the AC side, and causes the rotor to stop. (magnetic braking).
So...... A week or so of testing at 12 Volts to iron out any bugs with the machine, then I'll take it down and make any modifications, final coat of paint etc.. After that the turbine will be installed again, hopefully for good. Then I can run some 24 Volt tests and adjust the air gap to try different cut-in speeds etc...
I should get plenty of Video, pictures and data to post here. So keep any eye out for the "Test Results" section appearing soon. Fingers crossed. ;-)