bright days good winds

[blueyonder]

 im a happy guy. not making a lot of power yet but working on it so hard.

 im doing things one stage at a time . so must be called ground testing.

 as the gen is isent in the air yet.

  but thought i will post a few pics with how its going so far.

  in time i will get it up in the air.  but for now im just playing with it and doing what testing i can .

  i want to look for rust look for bits coming loose. and get the general feeling of how things will be .

  its no good waiting till its high in the air then trying to fix teething problems.

  as its my first gen i got to so how it functions.

  as you can see its ground level and not much clean air.

 but that dident stop it putting on a good show for itself.

   it looked so happy  and was willing to do its verry best.

  its just on a test stand i made.  no tail yet just fixed .

   it was a west wind blowing . and got a few good gusts.

   with the wind allmost dropped it will still turn good.

 im not the best at understanding electrics .

  but this is what i can do.test the AC in a strong breeze two phases put out 9volts

  so testing two at a time its just over 9 volts ac.

  so dos that mean each phase is 4 1/2 volts ?.

 if so then its 13 1/2 volts ac.

  i have three bridge recs. and think each one will consume 1 1/2 volts each.

  so 4 1/2 volts lost.

   the dc wires go to a battery. battery is at 12 1/2 volts.

  so the only reading for dc i can get is the battery reading.

  its not making enuff power to charge the battery,

   i understand that cos its on the ground.

  if i fitted a diod between b/rec and battery could i get a reading with multi meter for just dc from gen ?

   as yet in strong gusts of wind it dosent go over battery level.

   can you measure all three phases at the same time? its star connected.

   i havent checked the RPM YET . SO WILL TRY GET SUM READINGS .

   6 coils 8 mags six foot prop..

   this was a gen i started with a brake drum and ceramic mags.

   now modified it to be like the hugh piggot 4 footer.

   its a hybrid to be honest.

   so far the only bits that cost monie  

  resin and chopped glass -  magnets - 9" steel rotor .

 every thing else is what i had in junk form.  s/s allstud and nuts and small bolts i had to pay for.

  cutting discs and grinding discs welding rods etc i need to use anyway

  so i understand every one on here like pics. so enjoy.

[sdscott]

Nice work!  

[vawtman]

Nice work Yonder

 Your open voltage 9v is what you got at that rpm i would say.

Is your alt an aircore?If so maybe just add a blank rotor to give it a boost.

 Where are you from?

[kurt]

your math assumptions are all goofy. you multiply by 1.7 iirc to figure out total voltage when measuring across 2 wires of a star wired 3 phase alternator to get approximate 3 phase voltage. someone correct me there if i got that wrong)

 your voltage drop for the bridge rectifiers would be  1.5v total they don't add just because you are using 3 of them unless they were all in series and that would be silly.    

[Janne]

Hi!

Your blades look excellent-you obviously have some talent in making them

But it looks to me like your generators cut-in speed is too high. What sized magnets are you using? How many turns of how thick wire are in your coils?

Like already mentioned, using a second blank rotor in the generator would help, as it would complete the magnetic ciruit.

Good luck and have fun.

[blueyonder]

 thanks for the nice comments.  i really mean that .

 kurt you say my maths are goofy. its not my maths its me who is goofy when it comes to trying to understand the electric bits.

 so kurt you say if i  get 9.5 volts ac. then multply that .

  9.5 x 1.7 = 16.5. am i doing it right. sorry to ask .but i just cant understand this

  .

  and you say i only lose 1.5 volts for three bridge/recs.

  i thought maybe it will be better to use two b/r . but now you have said that then im much happier with three.

  sorry i cant see the posts . but dont know who said the blades are nice.

  there what i got out of hughs book.   it told me every thing to do. great.

  only i used 8foot and scaled it down to six foot.

  the little block wedges are great that fit on the root.  a great idea.

  i thought i knew a thing or two about woodwork.

  but fallowing the plans for the blades was sheer genius.

  kurt thanks for saying about how to measure three phase ac.

   i was thinking i must need a meter with three probes .

  but if my maths are wrong what i typed out can you say again please .

  so if i get 16.5  minus 1.5 that is 15 vdc.

  from dc side i only get 12.5 and thats the battery voltage already.

  i will try open circuit reading.

   i dont know any speeds yet. rpm. but the cut in speed must be more than battery voltage.

   its not fair to ask it to charge a battery on the ground gen i mean not battery.

   to put another steel rotor on then i need to make a new shaft.

  if i make a new shaft .  i can test blank disc steel.

   then after that i maybe add magnets.

   but i need to be busy sorting a mast of sum type and getting guy wire rope.

    the stator at the back looks a bit bare. im sure a rotor on there would look better. cheers all.

[ghurd]

Looks nice!

You could add a small donut of laminations on the rear.

Microwave tranformers have a lot laminations in just 1.

It will pull quite hard.

Not sure if the output would rise a lot.

Might not be a great idea...  Interesting to think about.

G-

[SparWeb]

As your photos slowly loaded, I wondered "what is that weird white haze?" in the second photo... Ahah, then the third picture loaded and I realized what... Look at that thing go!  

[hiker]

this I phone is a hassle to type with(my boys toy).. If you have acsse to the star point. .you can take a reading from there for each phase. .nice mill..

[blueyonder]

 not to sure about replying vawtman so hope this works.

  i am in essex. not to far from norfolk . whare all the windmills are.

 but we do have lots in essex aswell.

[blueyonder]

 hi janne ive just found out how to reply to you.

you asked about wire turns and magnets.

 wire size 15 awg  80 turns per coil.

 magnets n42 2x1x1/2".

 i dont know about the cut in speed.yet

   

[blueyonder]

 hi ghurd there is a lot of pull on the other side of the stator. its very strong.

  as you say and nothing to work on. i will make new rotor. same as the one on there.

  be interesting to see how much improvement it will make.

[blueyonder]

 thanks hiker. i understand what you mean. i will try and do that.

 but one problem is i used talk in the stator so cant be sure whare the star point is.

 i need to look at my old pics maybe i can try drill a hole to it in resin.

  i connected  the three starts together with a brass terminal.

  so if im lucky i can find it. maybe i need a x-ray.

  now i understand talc makes resin cloudy .

  so was a bit puzzled after seeing photos of stators that were so clear .

  so all them clear stators have no talc in them to help with overheating problem.

[ZooT]

Is overheating a problem with single rotor air core turbines?

[ZooT]

I've got this idea that came from making a bit of a mess when putting my minigen200 together.

JBKwik epoxy is magnetic, and one could try smearing a coating on the stator opposite the magnets and it might serve the same purpose as laminations do...

[blueyonder]

 sorry zoot i never saw this before.

  so only replying now.

 single rotor wont have any heating problems.

 but as it was my first attempt at casting a stator . i mixed in the talc for good measure.

  still haven't got a mast up yet  .so going to make a new rotor and make it a twin rotor..  as i already have the mould it should be a bit more strait fall ward.

  i think the hard bit will be lining up the mags .

  but nothing is strait forward. knowing my luck.

  shame on me for thinking so negative.