News for Electrondady

[Allan]

  The center rotor on my assembly is steel, because it is mounted to the bearing hub. It is the driver, an epoxy or fiber glass center would never stand the torque. I do not understand your assembly though. I have had good results yesterday in some good winds. Maxed out at 35 amps.  at cut of 13vdc I achieved 9 amps. I had received a note on my topics from someone who was going to use 3/4 " neos inside the microwave magnets. And expected 10kw. at 200 rpm. I would like to know more about this, because on a 14' prop cannot deliver the watts needed. the tail and furling systems are at their max when it comes to strength now.But anyways I would like to know more on yours.

   Bye for now  Allan

[rotornuts]

the 10kw unit is jimovonz, his rotor diameter will be in the 24' range and I'm about convinced now his rotor blades are off an MD500(hughes 500 or OH6A)helicopter which has a rotor diameter of 24-26' depending on the variant. I think that ought to do it!

[jimovonz]

Hey Allan,

I'm the one shooting for 10kW @ 200rpm using micromags. Though I have definately seen an improvement using the 3/4" neo infills, its more the fact that my alt will have a grand total of 288 micromags (from 144 microwaves) on a large diam rotor that will push my alt output up there. I don't know how close to my target I'll get, but the more I experiment the more hopefull I become. I have also had success boosting my output using laminations with my test coils (still retaining my dual rotor setup). Obviously such a large alt requires matched blades. I have three helicopter blades 3.6m (11'10") long that will make for a 26' diameter prop once I mount them on a suitable hub. The whole assembly will probably be pushing 500lb once its together. At the moment I'm still collecting and dismantling microwaves, and scouting around for a suitable yaw bearing assembly that will reliably handle the offset weight. I have a diary entry about the alt construction here:

http://www.fieldlines.com/story/2005/1/20/235641/582

I have since machined the ridge off the brake drum and modified the larger wheel rim to allow three rows of magnets - I'm just waiting on the magnets! I will also have to order more of the neos as I only have 80 at the moment.

[electrondady1]

hello allan ,thanks for the update . don't want to mislead any one, my little  unit will be on a very modest scale compared to most. but the design is sound. my first prototype has been up for one year now . it works in the slightest summer breeze but is rugged enough to handle incredable gusts at -30c .  its a vawt so the forces involved are much less intense . i hope these photos work , this computor stuff is all new to me. there are two like this

and one like this

[electrondady1]

sorry about the size, they looked good in preview. i'm just spining the coils  now. infact i better go the glue is kicking and i need to remove the coils from the jig .

[electrondady1]

allan,howdy, i've been thinking about the way you originaly laid out your stators. a half coil offset. was wondering if you came to any conclusions as to why it did not produce as you thought it should. the reason is , i am about to form my stators. the coils i have formed are only 3/16" thick. there will be 12 on a single layer. but i was having second thoughts as to the strengh of such a thin stator. i posted this guestion and "flux" ( a very knowlegable fellow) said i could double up the coils to make a 3/8" thick stator . that would be 24 coils on two layers . naturaly it occured to me to stager the coils . but in effect that would be the same lay out as what you had tried but within one stator . any thoughts? if i go this route unfortunatly i will need to spin another 24 coils for the second stator, but i can live with that if i get better power.

[Allan]

   Good afternoon electron

  In answer to your questions, I believe that for a unit to be true 6 phase then all starts of each phase would have to be tied together for a true star, the same as a 3 phase unit, with my stators offset this did not seem to be the case. I was using 2 rectifiers , the type you find in carand very large truck alternators . I think that I had a bad rectifier when I was doung some of my tests. I did put the stator back in line with the other and all is fine now. as well as 2 new rectifiers ( buy new ones , the old sheee don't wrks)In prepareing my coils, I've found a little trik,

 after winging them and tying them off,I machined a small mould from teflon and placed the coil in it with some resin. after they dried they were solid. This compressed them also to the thickness I wanted. After winding in the jig them seemed to swell back a bit, so the new mould corrected this. When casting the stator I layed done a piece of fiber glass cloth , set the phases back in and covered it with aother sheet of cloth. Finished pouring and then clamped it. with a sheet of melamine on top, it ozzed out at the sides ,but the parafine wax made clean up easy. My stators ended up at .350 thick.the coils after the mould process were .312. I am quite satisfied with the stators. My total air gap mag face to mag face is .437. Roughly .040 clearance. There is room for finer ajustment, I will wait til the hot weather to see what happens. In the mean time I am starting the THIRD stator and another center plate . A 3 stator machine. I hope that this info helps you.

    Bye for now Allan