stator cooling

[blueyonder]

 i have only made one stator.  and its good as new.

  it dident make a lot of power but that was my fault.

  and now im going to make another .

  this one will have two rotors.  first one was a single rotor hence no power.

  already i am thinking about fitting in sum air cooling .

  why fit air cooling.  it cant do any harm and wont affect the working of the gen.

   so why not help it vent while i can at the building stage.

   ive seen sum others put vanes to move air .

  i have never had heating problems and i am only considering it might help.

    i do understand thay can get hot . sum things are meant to run hot.

   this time i will fallow the advise given in the wire dia and amount of turns.

   i have a problem with myself. in the fact that if 70 turns of wire

   is called for . then i think if i put a extra ten turns it will be better.

   so  i don't know enough.

   but will all the reading i do on here i am getting a bit wiser .

   and now i have a much better understanding of cut in speed.

   prop speed and stall.

    like a car engine under a heavy load it will get hot.

    its making power.

   but a wind gen can run cold without no problems. air cooled.

   a proper wound set of coils and correct magnets set at the very best layout

  is the answer .

 so if it aint broke why fix it.

   again that is just how i am with things.  tinker-tinker-tinker.

   sure i want power from a up and running mill.

   and all the time i am tinkering with it. it doing nothing.

   i just enjoy trying to do wee bits that can help out. and for free.

    so i put sum pics on to show how i was thinking about stator cooling..

    but now im not so sure i need do this.

   why dont i just put holes in the stator.  it will save resin.

    well i don't see many holes on other stators being made on this site.

   most look like a very flat surface.

  why dont the masters put holes and such things.

   if thay  do no good then that i can understand.   but what benefit is there

   not to put a air cooling helper in at the build time.

  the type machine i am building will furl.

   so on to the pics.

  this was a trial with plaster of paris.   i was going to incorporate this

 in the stator.

  with vanes in the rotor to help move air.

  i don't live whare it will freeze or fill with snow .

    the small fins are brass.  a lot of extra work. yes.

   will it help. maybe . sure cant do no harm.

  i can make sure i put extra glass mat in with the resin.

     

[blueyonder]

 oh now i am adding a comment to my own post  as i forgot to upload

 the pics to my files folder.

[Flux]

You would do far better using all the winding space instead of 1/3 of it rather than playing about with holes and wind.

I am sure there can be improvements in cooling especially for those who feel that they don't have to pot the magnets for weather protection, the magnets probably fan as well as your vanes and the critical thing is to get the air flow in the right place.

Rather than tinker you could do us all a service by doing some scientific evaluation of the effects of these holes. There has been lots of speculation about this but no facts that can be validated.

There is far more evidence to show that using a larger copper section to use all the winding space is effective. It's difficult to remove heat, best not generate too much of it.

Flux

[blueyonder]

 

 hi flux and thanks for the comments.

  now i have had time to digest what you said.

  as i am only learning slowly  then i went bye the book when it came

 to potting the rotor.

  only adding small vanes.

  but from what you said about about air from the magnets . if not potted

 sounds a good idea.

   so now i understand i can make a compromise and only half pot the mags.

   still cover them with glass matt.  

    so i will just half fill the rotor mould this time.

  no lid  and just stipple the matting with a brush.

   it wont be a perfect finish but will move plenty of air.

   but i will make sure the brush has a stainless steel metal band.

  if need be i can do a bit of sanding to get a better look.

   i suppose in a way this is a short cut.

   but now i understand a lot more .this will save resin and provide a good airflow.

   magnets will still be covered as well.

   and saves all that messing i was trying to do with the vanes.

   as you have said in the past its knowing where you can take short cuts.

 as this is small 9" rotors i am using here i cant drill holes near the center

  as is done on the larger gens of the rotor to help with air flow.

   as far as filling the winding space with copper

   then i still need to ask for advise on that.

 but i understand now what you mean  .get as much copper as will allow with the same amount of turns. just make the dia thicker.

 when i first started to wind test coils i was surprised as to how small thay  

  looked. against others i saw on here.

   putting then on the scale i new thay were to light in weight.

   i almost have that problem sorted out .

   but of course if i put to many turns of wire it will lower my cut in speed and go into stall.

   as my real love is working in wood i find trying to make electric at home

  a real challenge .

   but getting a lot of understanding here on this forum .

   i have one book written by hugh and looks like i can invest in a new one soon.

   he has a new book out. great just what i need.

  but i am still going to make holes in my stator.  thanks flux.

 

[vawtman]

Hi Blueyonder,

 I would build a temporary template to hold the mags from sliding around.Then use a long cure epoxy(not jb weld or other quickies).Would be no need to pot then.

 The ill wind from the mags may do some good then :v)

 Mark

[blueyonder]

 hi vawtman .im sure the ill wind will do sum good.

  on the first rotor i did use epoxy glue.

 and then potted it . first to be sure the mags dont get out.

  then the other was to let the resin protect one of the most expensive things

  i have bought in a while.

  sure wouldn't like to see them magnets go rusty.

 so as i said i will only half pot them.  hope you can understand what i mean.

   and the resin i save i can use on my boat for repairs .

[vawtman]

 Surface rust is a great primer for epoxies.My rotor is out in the rain rusting on purpose.

 If your using new steel lightly sand it to remove the protective coating so it can rust.

 Seems crazy but true.

 Are your mags protected by nickel now?

[blueyonder]

 

   well a very interesting reply vawtman.

  at one time my was working in the oil refinery's.

  the company i worked for built oil storage tanks. and pipe lines

  but one thing puzzled me when a tank was finished it was left for about

 three months before it was painted.

  of course in that time it was covered in surface rust  .

  to me that was very bad and couldest understand why it wasent painted sooner  

   and now after all this time i understand why .

  a twenty five year mystery solved ha-ha.

   so now i can leave bare metal outside if i am going to paint it soon.

    after wire brushing it of course .

  a good tip vawtman. i also found old brake fluid is great for cleaning a old paint

   brush that had gone hard.  

   were never to old to learn new tricks.