alternators: 3 phase: wire size

[brandnewb]

I have 0.4mm diam, 0.7 and 1mm diam wires available.

The 1mm diam is far too stubborn (just like I am ) and does not want to stay in shape. Hardly favorable conditions to make many coils with.

Now I could flex some prowess and show how to unpractical create iron filled 1mm wired coils.

It would be a neat show of skill but not at all practical for larger scale systems.

How fast do things get to too hot with what wire size? is there any type of rules of thumb?

I just checked again my Hugh Picket kindle but I am just not sure this information is still applicable.
I realize that I am cursing in the church. Yet someone has to do it if information seems no longer applicable.

[Mary B]

1mm is approx 18 gauge... that isn't that thick... many of the machines here were wound with 14 gauge(1.628mm), some with 2 in hand(2 wires would at the same time in parallel when finished) which is equivalent to a single 2.3mm winding...

If I was using 18 gauge it would be 2 or even 3 in hand for 2 or 3 winding in parallel per coil for higher current capability

[SparWeb]

Refer to this:
https://www.powerstream.com/Wire_Size.htm

Use the column "Maximum amps for chassis wiring"

Since you have CAD tools, it should be easy for you to estimate the length of wire you will wind into each circuit. 
From the table then you can calculate the resistance in Ohms for each circuit or phase.
Then do the Ohm's Law calculation to find the voltage you need to produce the maximum current.
Test the coils for the voltage produced at a range of RPMs.
You then have an estimate of the rated power of your alternator.  Usually you can get more without burning up, but not too much!

It's pretty accurate, too.  I've been through it a couple of times and always impressed/satisfied/amazed by how directly the theory lines up with the practice.

[brandnewb]

Thanks all for the input.

It made me realize I should think harder on how to mass produce coils in an effective time frame.

I think I found the solution. I am now post processing a peg board with, well, pegs to keep the 1mm wire in place

[brandnewb]

I am happy to announce yet again some progress on the MK II.

First arm is installed, And it aligns to the wind direction as can be seen by the weather station that is now near by.



EDIT: hahah please do not think these indoor scaffolding are what I was referring to when I asked about how to align a 6m column. I have also more large scale scaffolding that is meant for outdoors and high +8m works
But one can imagine that setting that up requires a bit more time and we do not need all that much height at the moment.

Also MattM, Even though I will seriously make it so that arms cant tord and/or bend and what have we. These arms are aluminum. Does that make any difference to ease of metal fatigue?

EDIT2: and I take care of avoiding contact between steel and aluminum as to not cause hotspots for oxidation/ rust forming

ADDITION: I am considering renaming the structure to the Apache attack helicopter if the US military will allow for it.


EDIT3: blunder spotted. top arm needs to be flipped

EDIT4: hahah false alarm optical illusion at play here

EDIT5: not a false alarm at all. I will go and have a talk to anyone that ever suggested that building turbines is easy

[Bruce S]

 I will go and have a talk to anyone that ever suggested that building turbines is easy

Anyone who says this probably has never attempted to build one  .

The build looks pretty good. I'm also a little worried about the wind load on the structure alone. I can't hold a candle to Mary B's ability to calculate the loading but I'm certain it's gonna look like one big brick !!
Stay safe and don't take your eyes off it ones it starts turning .

Bruce S

[brandnewb]

yesss I am not even going to ask for permission of the US military.

MK II is now officially called (the) Apache

[Mary B]

I am happy to announce yet again some progress on the MK II.

First arm is installed, And it aligns to the wind direction as can be seen by the weather station that is now near by.

(Attachment Link)

EDIT: hahah please do not think these indoor scaffolding are what I was referring to when I asked about how to align a 6m column. I have also more large scale scaffolding that is meant for outdoors and high +8m works
But one can imagine that setting that up requires a bit more time and we do not need all that much height at the moment.

Also MattM, Even though I will seriously make it so that arms cant tord and/or bend and what have we. These arms are aluminum. Does that make any difference to ease of metal fatigue?

EDIT2: and I take care of avoiding contact between steel and aluminum as to not cause hotspots for oxidation/ rust forming

ADDITION: I am considering renaming the structure to the Apache attack helicopter if the US military will allow for it.
(Attachment Link)

EDIT3: blunder spotted. top arm needs to be flipped

EDIT4: hahah false alarm optical illusion at play here

EDIT5: not a false alarm at all. I will go and have a talk to anyone that ever suggested that building turbines is easy

Aluminum work hardens over time then cracks when put under a lot of bending stress, I have lost antennas to that because of ice loading making them droop way to far, stresses tops of the booms and that is where failure happens...

This is work hardened aluminum, there was a piece of 1/4 inch wall angle that ran up one side of this that I never found... probably landed in a field during that storm with 80mph wind gusts for 36 hours. This was a 25 foot tall vertical antenna that tapers to 3/4 inch thick at the top in six 4' sections... Note the blackened metal where corrosion crept in...

[brandnewb]

wow, gnarly ;(

Now one gets to appreciate why I want things spinning slooowwwwww

[brandnewb]

one big brick !!

Is air that dense? I hope you are mistaken because otherwise I have to really really start thinking about top braces and ground hooks.

Not something I am looking forward to as you might have guessed

EDIT: nah grounding an Apache attack helicopter would not do justice to it. So perhaps better to let it take off if it wants to

[brandnewb]

WOW,

I have had tries before but this looks soo good!!

this is at around 75% iron powder vs easyflo 60 poly resin.



ADDITION:
Ok, I'll no longer try and hide it. I am impressed if I may so my self.


whatever3:
Also resin is not known for good thermal conductivity but iron is. So having iron filled coils will help with heat dissipation!!

[Bruce S]

The one big brick statement come from my engineering class on Blueprinting and such.

BUT yes, air should always be thought of as a fluid. It's of course not as dense as say water which is ~~8x times as dense as air.
BTW: Army cannot hold you back from calling your design Apache due to the name being use about 100+ years before the Bird was ever built.

We're not here to hold you back only to help you know the possible hazards and to stay safe.
Personally!? I like the design and am following this thread when I can. I also like the waterway in the background.

Leverage can be your friend, One of the things you might need to do while deciding if you are going to stake it to the ground and getting data once it's "grabbing a breeze or two", would be to make the 4 legs longer and put as much weight on them as possible (without ruining the lawn  )

As you can see from Mary B's post; Aluminum can be a friend but can also quietly become a danger
Cheers
Bruce S

[brandnewb]

I also like the waterway in the background.

It has got sharks with freaking laser beams attached to their heads in it

famous quotes Dr. Evil

[brandnewb]

Leverage can be your friend

Thanks Bruce,

I love it how sometimes words like leverage triggers a thought process that leads to possible solutions.

At a later time I might get back to one of those solutions No need for too much grandstanding at this stage in time. I mean we do not even know yet who is going to pilot this helicopter

[MattM]

You are going to discover the C-shape will act as wind buckets.  If only there was a way to mount them to 2x4's as actual buckets.  Your wood will tolerate fatigue about 1,000x better, too. 

[brandnewb]

Do you mean putting wood into the alu C to make it a solid rectangle rather than a C shape?
I can do that.

because what is happening now is that the arms are rotating back and forth in the little wind we have at the moment. So I guess it is because of the C shape like you said.

ADDIT 1 :
I found a pilot capable of flying the Apache.
here you see it rotate in one direction but it goes back and forth
who needs blades anyways?


Also I will stake it to the ground for my peace of mind but will do so that one can't tell it is fixed. So it will look like free standing

[brandnewb]

Again out of sheer respect for the title of this forum.

Please witness fieldlines frozen in time.



frozen because the resin has settled in the mean time. But at a shore of 60 (a term to define hardness) it is still easy to break at these thinly defined lines.

[brandnewb]

MagnetJuice and Adriaan

I have a question.

in this beginner level video I finally heard that a factor is about the velocity of cutting through the lines of flux

https://www.youtube.com/watch?v=KUrMt6ic53o\

at somewhere short after 2m:00s

Is not the easiest way to do that to increase the frequency of field rotation? I still firmly believe it is but of course I am happy to be shown wrong.

{}
WOW I just found that having alu arms will cause all kinds of spectral (visible light) aberrations. I have never worried about my neighbours complaining about noise. But I am starting to think that light pulses might be the one that does this whole design under ;(

I can coat it sure but I am starting to second guess my choice for aluminium

[brandnewb]

You are going to discover the C-shape will act as wind buckets.  If only there was a way to mount them to 2x4's as actual buckets.  Your wood will tolerate fatigue about 1,000x better, too.

Yes brother. Please review the previous statement I made. This turbine without blades is spinning quite readily at the moment.

should I go and go for wood inserts?

 

[Mary B]

MagnetJuice and Adriaan

I have a question.

in this beginner level video I finally heard that a factor is about the velocity of cutting through the lines of flux

https://www.youtube.com/watch?v=KUrMt6ic53o\

at somewhere short after 2m:00s

Is not the easiest way to do that to increase the frequency of field rotation? I still firmly believe it is but of course I am happy to be shown wrong.

{}
WOW I just found that having alu arms will cause all kinds of spectral (visible light) aberrations. I have never worried about my neighbours complaining about noise. But I am starting to think that light pulses might be the one that does this whole design under ;(

I can coat it sure but I am starting to second guess my choice for aluminium

Easy to dull it via anodizing BUT the chemicals involved are not friendly to skin! Lye turns skin to soap, you won't feel it burning until to late, and sulfuric acid is just nasty... add black dye and presto, no reflections. Painting can be done but it takes proper surface prep and primer, same for powder coating...

[JW]

I figure this will show up at some point

By Lenz's law, an eddy current creates a magnetic field that opposes the change in the magnetic field that created it, and thus eddy currents react back on the source of the magnetic field. For example, a nearby conductive surface will exert a drag force on a moving magnet that opposes its motion, due to eddy currents induced in the surface by the moving magnetic field. This effect is employed in eddy current brakes which are used to stop rotating power tools quickly when they are turned off. The current flowing through the resistance of the conductor also dissipates energy as heat in the material.

https://en.wikipedia.org/wiki/Eddy_current

JW

[brandnewb]

thanks guys. I will figure out a way to coat the alu. this is crazy at the moment this light show.

Also JW, thanks for reminding me about eddy currents.
I have made sure that the iron powder used to cast the coils in is non electro conductive. So I am hoping this will make the impact of eddy currents even more negligible than using traditional coil plating.

Also we have a 9 m/s wind at the moment hammering on the Apache. It is not taking off staying firmly on the ground. Bthe harder the wind blows the less the arms rotate weirdly enough.

BUT they vibrate like crazy. Really fast. If I ever saw metal fatigue in the making this is it!. this needs to be addressed else this bird will start loosing arms rather soon!.

{1}

Wooden inserts?

I have decided to kill 2 birds with 1 stone. I will use duct tape or something similar on the arms to reduce their wind catching capabilities and light reflectiveness
below one can see it vibrate. this was not even the most violent


{2}
Disaster averted. These were a really  scary few hours. And then to think it has been vibrating all night while no one noticed.

[brandnewb]

So I have bought some time to really implement the best solution. So I am open to any and all suggestions on how to tackle this.
I probably will implement more than one method.

{1}
Now my mind is free from fear again I just had an epiphany. I am starting to believe I can get a single non stacked coil to consist of 100 1mm diam wires. You know those temperamental ones that really do not want to listen

[JW]

https://www.fieldlines.com/index.php/topic,137297.msg1063318/topicseen.html#msg1063318

[brandnewb]

Thanks JW, I followed the link and found a thread that seemed to be about alternators.

Is this a friendly reminder that this topic is being diluted by my progress posts interweave with the question at hand because I tend to agree.

Perhaps moving all Apache related posts to a new thread. it would be ok to have it in a logged in dairy if it is deemed unsafe for public viewing

[JW]

No


   The thread im referring to is about eddy Currents in the stator windings, the stator almost started on fire. "wire in hand" is how we solved this.

[brandnewb]

understood sir! I will go read more about it.

Also what if I make the arms shaped like something that creates a downward force. Sure it will introduce more efficiency losses but I really am not looking for the world record in efficiency I am looking for something that will need no more maintenance than once a year after 6 months of service

BTW: that is not entirely true. Because if I, over time and trail and error, can build the Apache so resilient that it can go years without maintenance then I might start wielding my political prowess and lobby for acceptance of the Apache on our roofs. I am sure there are many people that will want one if one can trust it

[JW]

I have a hard connection, phone, internet, cable. I get it all thru coax cable. I am involved software development. I have a 2 page text document that's just awesome its about BIOS and UEFI - compliant systems. Don't forget I own this place and are a lifetime member. 

[Mary B]

To address vibration add a truss arrangement over the top that goes halfway(Minimum, think truss) out each arm. Will also help sag once you add the weight of the buckets on each end... Can be as simple as 1/4 inch rod "soldered", use a propane or Map Pro plumbing torch and the readily available aluminum "welding" rod. Both should be available at any hardware store. But the aluminum will eventually fail, nature of the beast!

[brandnewb]

Thank you Mary, I will keep the suggestion as a close consideration.

BTW! My pilot said he has gotten a call from Boeing and they asked if there are more similarities to their AH-64 Apache and My dangerous contraption.

I think I have chosen the right pilot for the job because his answer was that only the frequency of vibration felt similar. The rest is far too experimental to have a say about.

He did resign though after this debacle. But fear not I have gotten my degree for the AH-64 in a mere 2 hours So now I will be the one flying this bird.

going down!!
brace for impact!!

{1} now it is no longer only a funny story I like to tell to entertain the reader.

Now things ar not going down but going up.


I have spend another hour fighting this beast and this winds. It's brutal!!!



I came soo ill prepared. And the material I bought came straight out of a sweatshop without any quality assurance procedure. One cable tensioner just got tore in half!! this is insane!!

If the bird still stands tomorrow I will give her the love she deserves and start upgrading to oversized material that came from a source that has known good stuff.

{2}
so in a weird turn of events I am now putting more faith in what I at first thought as the weakest link. I never saw this coming!!

{3}
Bruce, I hereby declare your predictive capability as assessed and it has cleared the strictest of quality control
air is brutal ;(

[MattM]

You are going to discover the C-shape will act as wind buckets.  If only there was a way to mount them to 2x4's as actual buckets.  Your wood will tolerate fatigue about 1,000x better, too.

Yes brother. Please review the previous statement I made. This turbine without blades is spinning quite readily at the moment.

should I go and go for wood inserts?

I was more thinking replace them with wood, split the C-channels and mount on to the wood as wind catchers.

You may want to stiffen your whole contraption.  You can run cross beams from your legs to the pivot point to stabilize that easy enough.  May take a pyramid shape but it will be strong.  Your current guy wires are using the legs like a crossbow.  Need something to resist the legs bowing.

[brandnewb]

Yes thank you Matt and all.

I have taken down the arms to be able to lick my wounds in peace. {1} literally as well nothing really bad but superficial cuts/scratches that never really bleed to begin with.

What I did do though is spare no expense and ordered components from a top German manufacturer. Sure you pay extra but things will not snap while below the rated capacity. And I went extra large this time.

This is one of those learn from my mistakes moments ;( Never go stingy while working on wind turbines ;(

Now as for the replacing the c channels. Please do not think I am dismissing any suggestions. But my OCD wants to see what happens if I pre tension them while they are no longer c shaped. I am making them solid rectangles now using rigid insulation to keep the weight down. Weight was what made me choose alu to begin with. I will admit that this might have been better to first ask advice about ;(

{2} And visually the arms are still fine but by my current understanding only through acoustic analysis can one detect early sings of failure.
Save to say that this is soo far above my pay grade that I will not even bother with that and just assume the alu is still fine. I mean what can go wrong right?
But if one knows other less out of reach methods than I am all ears of course.

{3}
Would you please elaborate about what you meant on how to stiffen this bird Matt? I mean we already have a pilot that resigned and are now stuck with me as pilot Finding a test pilot that is far more capable of flying an Apache yet also willing to risk life is farrr more difficult than regular ones.

[MattM]

I'm thinking inside/under of your guy wires you run cross bracing.  Your fulcrum is much shorter this way and should nearly eliminate bowing in the middle.