hi David!
i am currently making a 1hp genny with the curved/skewed magnets (arc segment with a skew)
they are approx 1 3/4 inch long by about 1 1/4 inch wide and skewed. i have drilled a 3/16 hole in each one and tapered the hole at 82 degree to accept the tappered head of the stainless #8/32 screw.
i used a 3/16 carbide tipped cement bit and sharpened it to get rid of the factory round edge until it is sharp. for the taper bit i also used a 5/16 cement bit and tapered it (eyeballed the taper) and sharpened it. use thick cutting oil when drilling, and often lifting the bit and applying more cutting oil. works fantastic. never broke a mag.
clean up after though is a hell of a mess.
these mags came from a dealer in canada. his name on ebay is "tropical sun" his name is Kenny Dyal. his e-mail is nrag1662@rogers.com
he is a great guy to deal with, gives good pricing and quick service.
they will fit rotors (before turned down in a lathe) of approx 3.75 to 4 inch. about 1 to 1.5hp and even some 2 hp motors.
at present for this 1hp conversion, i am making a 4 pole rotor. 2 mags per pole. it is a little wide for the coil span and will likely cause some coil cancellation. will post the results later on. just to let you know, it is quite a struggle to get 2 mags of the same polarity tight together on the rotor face. this is why i am screwing them down. will probably also put a very small amount of epoxy under each mag.
i intend to give Kenny some future feed back as to a more specific size and thickness to better suit the stock 230/460 volt windings. i would much prefer to have 1 mag per pole, and with the screw hole and taper provided from the factory.
they may be a little more expensive, but being able to convert the rotor without a magnet cage for the round magnets, the epoxy, the extra labour, i beleive they will be much cheaper to do in the long run and give a very superior unit compared to the way i do it now with the round mags.
you can view this project in progress starting with the last picture in row one on page 21 and continuing to page 23. there is no picture of the rotor there yet, but it will be added as it is completed. http://www.anotherpower.com/gallery/zubbly?page=21
hope this info gives you a source for the mags and some insight on how to convert the rotor. these skewed mags are new for myself and must learn to take full advantage of them.
have fun!
zubbly
