Kris Harbour 2 KW axial flux generator build up !

[topspeed]

This topic was split from "Wind Turbine Upgrade - 7.5 HP Conversion" -
Wind Turbine Upgrade - 7.5 HP Conversion

Here is a cool build up too.

https://www.youtube.com/watch?v=2-ExvwfNaMQ

[SparWeb]

topspeed,
Would you like to have your own thread for this?   >>>Done
I love fab videos, and I wouldn't want it to get lost at the end of my project thread.  If you agree, I will move it to a separate thread.  What title would you like it to have?

I always have lots of reactions to fab videos, thank you-
11:45 Nice trick with the brass studs.  Having a vertical mill sure is handy!
144:52 Wear gloves when you weld, man!
16:39 Gluing down the magnets is the WORST time to discover you marked the "S" pole "N".
16:57 That wooden disk would have made a nice tool to center your "spider" rather than do that by eye.
19:31 You would NOT want to do that with Neo magnets! 

[topspeed]

Yes...what ever name is ok.

[topspeed]

Spar Web wanted a new thread for this.

here we go: https://www.youtube.com/watch?v=2-ExvwfNaMQ

[topspeed]

Is there any better 4-10 kw axial flux build up video available ?


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This is ok ?

https://www.youtube.com/watch?v=bHzt74CE0fg&t=107s

[SparWeb]

Plenty of small ones!
https://www.youtube.com/watch?v=EPmW-BjCiWI
https://www.youtube.com/watch?v=f4cOX8Ora0A

Fewer big ones...
https://www.youtube.com/watch?v=d88jUiAxoO0
https://www.youtube.com/@scoraigwind
They all seem to be Hugh's projects!

[topspeed]

Plenty of small ones!
https://www.youtube.com/watch?v=EPmW-BjCiWI
https://www.youtube.com/watch?v=f4cOX8Ora0A

Fewer big ones...
https://www.youtube.com/watch?v=d88jUiAxoO0
https://www.youtube.com/@scoraigwind
They all seem to be Hugh's projects!

These are awesome thanks.

https://www.youtube.com/watch?v=EPmW-BjCiWI

[topspeed]

I was wondering that two row magnet system...does it double the efficiency ?

[SparWeb]

It doubles the current to have two alternators.  If the two alternators are the same (I don't know if they actually are) then they both give the ~25V output at 100 RPM at the same time.  So what you gain is 2x more current because you have 2x the number of alternators.  A lot like having two jars as pickles instead of one jar.  It's not 2x as sour, just more pickles to eat.

Or, if he chooses to connect the two alternator output in series, then it would double the voltage, for the same current.  That's like cooking with jalapeno peppers.  If you put 2x the jalapenos in the sauce, it's twice as spicy, but you don't have enough to double the servings.

[topspeed]

It doubles the current to have two alternators.  If the two alternators are the same (I don't know if they actually are) then they both give the ~25V output at 100 RPM at the same time.  So what you gain is 2x more current because you have 2x the number of alternators.  A lot like having two jars as pickles instead of one jar.  It's not 2x as sour, just more pickles to eat.

Or, if he chooses to connect the two alternator output in series, then it would double the voltage, for the same current.  That's like cooking with jalapeno peppers.  If you put 2x the jalapenos in the sauce, it's twice as spicy, but you don't have enough to double the servings.

I see, but it sorta increases the "drag" ?

[SparWeb]

I see, but it sorta increases the "drag" ?

Doubles the torque needed to turn the shaft at any given speed, yes.

[topspeed]

Yes of course...torque increases....

How close are the magnets to the coils in axial flux type generators ?

[SparWeb]

They are mounted as close as they can be, reasonably.  Too close and the disk scrapes the stator.  Any farther than that and you are loosing power.  I've seen gaps of just a few millimeters.  Keep in mind that it's a spinning machine.  Joints always have flex so you should account for that, otherwise the disks scrape when the machine is assembled and spinning in a storm, even if they didn't scrape while you assembled the alternator on the bench.

[topspeed]

Wouldn't rafial flux then be easier to get it closer ?

[SparWeb]

Wouldn't rafial flux then be easier to get it closer ?

Yes.  You still have the problem of the shaft flexing, so you can't have zero clearance, potentially enough to cause the magnets to scrape against the stator, but it's much less.  So you can have a tiny gap.

[Mary B]

Wouldn't rafial flux then be easier to get it closer ?

Yes.  You still have the problem of the shaft flexing, so you can't have zero clearance, potentially enough to cause the magnets to scrape against the stator, but it's much less.  So you can have a tiny gap.

Oddball idea... this will add a little drag but limit flexing... add roller bearings out near the edge of each magnet disc that hold it from flexing much... wouldn't need anything heavy duty here...

[topspeed]

Wouldn't rafial flux then be easier to get it closer ?

Yes.  You still have the problem of the shaft flexing, so you can't have zero clearance, potentially enough to cause the magnets to scrape against the stator, but it's much less.  So you can have a tiny gap.

Oddball idea... this will add a little drag but limit flexing... add roller bearings out near the edge of each magnet disc that hold it from flexing much... wouldn't need anything heavy duty here...

Wonderful idea Mary.

[topspeed]

I might need a stronger radial flux generator ?


https://www.youtube.com/watch?v=0aNKUOtZ2mg&t=315s

https://www.youtube.com/watch?v=7IsWKyoIz1Q

This is cool too:

[SparWeb]

That radial flux rotor doesn't have backing metal.  The field lines passing through air will have more "resistance" making the flux density weaker.  The discs mounting the magnets seem to be aluminum - missed opportunity.  Using either very thick solid aluminum or steel invites eddy currents, although what they're doing with those aluminum plates won't have that problem, at least.  If instead the disks were steel, thin, and stacked the whole width, then you'd have a pretty good rotor.  Mounting it on a shaft isn't addressed by what I see in that photo, either.  Another thing to work out on your own.

[topspeed]

That radial flux rotor doesn't have backing metal.  The field lines passing through air will have more "resistance" making the flux density weaker.  The discs mounting the magnets seem to be aluminum - missed opportunity.  Using either very thick solid aluminum or steel invites eddy currents, although what they're doing with those aluminum plates won't have that problem, at least.  If instead the disks were steel, thin, and stacked the whole width, then you'd have a pretty good rotor.  Mounting it on a shaft isn't addressed by what I see in that photo, either.  Another thing to work out on your own.

yes and I would nee the magnets to be on the outer rim and the coils in inner.