Building the sickest® VAWT ever. Brilliant minds unite please!!

[brandnewb]

After having seen many commercial turbines fail, under-perform and otherwise not life up to expectation I have decided it is time to put an end to this sad state of affairs.

I see no other option than to take it upon my self to DIY a VAWT and alternator that actually works i.e. that outputs an insane® amount of power at low (safe) rpm. I am aiming at 60-120 rpm.

I am a total newb, brand new even (hence my username), in the field as well as electronics so I would really appreciate if you lot can guide me along the way. Maybe even stop me from making huge mistakes.

It should go without saying that what will be discussed here is not without danger. Please all take self responsibility when tinkering with (large scale) power generators.

At the moment I am struggling with the alternator. I have planned a 3 phase system with 2 stator disks each having about 754meters of copper wire at 1mm confgured for 96 poles. the magnets are 60x10x5mm neodymium.

I am new to this forum software and do not yet know how to insert images. I'll be so blunt then to link to a topic that I started elsewhere
https:// diysolarforum (dot) com/threads/building-the-sickest-®-vawt-ever-brilliant-minds-unite-please.31934

We will be discussing airfoils and soldering and what not but please allow me to first ask should I use wood or steel for the disks?

[bigrockcandymountain]

How will you do 2 stator disks? Will you have 3 magnet rotors with one in the middle double sided? You definitely want steel for the discs, to make a return path for the magnetic flux. 

5mm is a very thin magnet for an axial flux.

96 poles wih only 10mm wide magnets might not work at all with the alternating poles cancelling each other out. 

How many watts are you wanting and at what wind speed?  A few things you said make me think you might have unrealistic expectations.  People have definitely tried what you are proposing, most with limited success. 

[brandnewb]

disk 1 is a stator with ciols, disk 2 is the rotor with the 96 magnets and disk 3 is coils again slightly offset as to be able to string each of the 3 phases together.

How does inserting images work on this software? I need to resort to linking expernally for the time being ;(
diysolarforum . com/threads/building-the-sickest-%C2%AE-vawt-ever-brilliant-minds-unite-please.31934/post-391631
diysolarforum . com/threads/building-the-sickest-%C2%AE-vawt-ever-brilliant-minds-unite-please.31934/post-391587

currently the disks are OSB 18mm but I can get my hands on 1mm cold rolled steel at 820mm x 820mm

[brandnewb]

Regarding the magnets. I already purchased, and have gotten, 48 of them. That was quite an investment so I really hope they can be of use.

I am looking to have the alternator produce something useful at 60 to 120 rpm. How much I don't know. The more the better

[brandnewb]

I could settle for 48 poles as that was my original intend anyway. But I got carried away and thought to cramp as much poles as possible onto the 82 diam. rotor disk as possible

[electrondady1]

two stators and one central mag disk is the layout that many beginners (including myself ) envision as ideal . but that is not so.
one stator disk positioned between two magnet disks is optimum.
the mag rotors need to be made from mild steel  and thick enough to contain the magnetic flux.
48/2=24 poles
24 poles x 10mm mags @50/50 spacing= 480mm circumference at center of the poles.
480/3.14=154mm dia. at the center of the mags so add 10mm = 164mm diameter rotors.
 or 6.5 inch mag rotors.
two skill saw blades would work as the rotors..

[JW]

Im thinking about the "magnetic circuit", is this even possible to have 2 stators efficiently? Im noticing the mention of skill saw blades.

[hiker]

https://www.fieldlines.com/index.php?action=search2

[Adriaan Kragten]

If you want to start with a Darrieus like VAWT, I advise you to first read my public reports KD 215 and KD 601. About PM-generators, you should read my public report KD 341 and an explanation about the design procedure which I gave only two weeks ago on this forum. All public KD-reports and manuals can be copied for free from my website: www.kdwindturbines.nl at the menu KD-reports. At the top of the menu KD-reports, you find the note: "Sequence of KD-reports for self-study" which gives you an idea of what subjects you will meet if you want to design a wind turbine.

[brandnewb]

The issue I imagine having with saw blade disks is that they tend to be small (largest I found is diam. 30cm) and thus unable to house enough magnets to create a usable output at low rpm. And they are quite pricey.

I could do tests with the 82cm diam. 18mm OSB disks for now only weaving a single phase and spin the rotor at +- 60 rpm and see what it does. I can weave the coil for a 96 magnet first and also a 48 magnet version and compare the results.

WHen I press the insert image icon all that happens is

unable to insert an image. How is that supposed to work?

[brandnewb]

I've looked at kdwindturbines.nl and am impressed as much as I am intimidated as I understand very little of it because I lack the technical background.

Could you tell me please what the results are of your "best" public alternator at 60 rpm. I apologize if it is clearly in there somewhere but I was unable to distill that.

[brandnewb]

two stators and one central mag disk is the layout that many beginners (including myself ) envision as ideal . but that is not so.
one stator disk positioned between two magnet disks is optimum.
the mag rotors need to be made from mild steel  and thick enough to contain the magnetic flux.
48/2=24 poles
24 poles x 10mm mags @50/50 spacing= 480mm circumference at center of the poles.
480/3.14=154mm dia. at the center of the mags so add 10mm = 164mm diameter rotors.
 or 6.5 inch mag rotors.
two skill saw blades would work as the rotors..

Would you happen to have any resource regarding this that I could try and read? I could replace the rotor disk for a 5mm steel one making the disk as thick as the magnets it self. Or should the disk be thicker than the magnets?

[joestue]

the steel backer plate can be half as thick as the magnets and it will do fine.

as for your prior question, its like asking what's the best transmission in the world, without specifying anything else.

the most efficient 60 rpm electrical machines would be the 120 rpm generators in hydro electric facilities. (just slow them down a bit)
a close second would be the axial flux motors used in certain US submarines to drive the propeller without a gear box. they have extremely low cogging torque and extremely low torque ripple (no those are not the same thing) so as to remove all the sources of noise that could be transmitted out the propeller.

[brandnewb]

We have a saying in Dutch.
"Meten is weten" translates to
"To measure is to know"
Hopefully gathering the results in the different configurations can help future projects along.

[brandnewb]

insert image test

[brandnewb]

ok great, this will make sharing my thoughts much more easy.

[brandnewb]

So my plan is to weave a single strand of wire for 1 phase in a 96 configuration and another phase at 48 configuration. so I only have to change the magnet configuration between tests.

If the 96 config does perform better then I will remove the 48 config coil and weave for strands to the 96 coil and continue testing wind per wind.

Changing the rotor disk to steel can also be done to see how that influences the results. I'd like to know what the difference would be between steel and wood

[brandnewb]

wow, according to easycalculation .com/analytical/inner-circular-ring-calculator.php I should be able to get 35 strands of 1mm wire in a 7mm hole. Not sure how I got 24 earlier

[MattM]

What kind of cost are you looking at?

[brandnewb]

the 48 magnets I have now were about e200, if my quarter diisk test with 24 magnets yields better results than a quarter disk at 12 magnets then I'll need to buy an extra 48 magnets for the full scale test.
osb was about e40. the 4 x +- 71m 1mm enamameled copper was about e100. I still am looking for a cnc milling service that can handle wood and that probably will not be cheap as well. And i'll probably need loads more of that

Then I'll be needing a 3mm steel disk to test the output of the magnets that will be around e50

[brandnewb]

regarding the weaving of the coils. I am worried it will take too long and is too unwieldy as I have to sow the whole string through each hole 33 times. Or split it up and solder back together and that already needs to be done every +- 71m as I can't find spools longer than that at 1mm. That is going to take ages if I even to have the discipline to do it. Nah it will be sheer madness.

Sow I am considering a square tooth approach. I'll share an image in a bit

[brandnewb]

So please see the square tooth coil winding idea I have.
It will enable me to keep the wire on the spool and wind it around the disk rather than having to sow the whole string through holes.
I will be moving the magnet holes and the square teeth more to the outer rim so that I can create more space for the copper wires for each phase. This is especially important on the inner teeth.

[brandnewb]

I am also struggeling generating gcode fot cnc milling. so this process is quite slow

[brandnewb]

now the teeth have about 5x5mm for winding wire on the inner ring with +-2mm of spacing.
I am only worried that the OSB teeth (the 2mm spacing) will be very delicate and might break off when only looked at.

[brandnewb]

or when I have 3mm steel disk. do they need holes cut out for the magnets or can I position them on the surface of the disk?

[Adriaan Kragten]

I've looked at kdwindturbines.nl and am impressed as much as I am intimidated as I understand very little of it because I lack the technical background.

Could you tell me please what the results are of your "best" public alternator at 60 rpm. I apologize if it is clearly in there somewhere but I was unable to distill that.

It isn't possible to call one of my generators the best one without having made a choice to which wind turbine rotor the generator is coupled. The generator and wind turbine rotor have to be chosen such that both match well together. Matching is explained in chapter 8 of KD 35. If you don't have the technical background to understand my KD-reports, you simply have to study them over and over again. Start with KD 35 and use this report together with KD 196 until you can answer all questions given in KD 196 correctly. General information about energy is given in report KD 378. Once you have the basic knowledge of KD 35, it will be easier to understand other KD reports about PM-generators and safety systems. Without this knowledge you should not design wind turbines. Badly designed wind turbines are very dangerous. You can always start with building a small VIRYA-windmill like the VIRYA-1.04 or the VIRYA-0.98 which make use of a Nexus hub dynamo and for which a complete set of drawings is given. Information about these wind turbines is given at the menu VIRYA-folders at my website.

My report KD 78 gives measurements for a radial flux generator made from an asynchronous motor for three different loads being different constant voltages, different constant currents and different constant resistances. This report gives a very good insight of generator characteristics which can be expected for a certain load. There are also measuring reports available for bigger generators (KD 82 and KD 200). A very simple small 8-pole axial flux generator with only one armature disk is described in report KD 679. This generator is meant for the VIRYA-1 and the VIRYA-1.02 which both make use of the same head as the VIRYA-1.04. The measurements for a 12 V battery load are given in chapter 9 of KD 679.

[brandnewb]

I have planned to build this turbine.
it's a 3 x optimized airfoil of +- 50 cm wide in helix formation 2m wide and 3m high

[brandnewb]

Does that help to select the "best"alternator?

I'd like to go head first going for maximum given the constraints I have. For example my local code allows for a turbine diameter of 2m (hence the above design) and the height of that design is based on how high it can be according to my local code.
This is an on the roof scenario. I have planned to first test this project out on my land. But then we might run into wind obstruction issues so I also plan to make the turbines stack-able. So from ground level I can stack 4 x 2mx3m.

Main goal is to go as insane® as possible given my local code. I am confident that will result in the sickest® VAWT ever

[Bruce S]

brandnewb;
There are quite a few discussions on here about wood versus iron/steel. Basically the wood doesn't have a magnetic flux path for while iron/steel does.

As far as OSB , you might rethink that have a look at ClockmanFRA's recent posts about his finds. Water (weather) will effectively destroy it in short order.

Used skill blades can be had cheap from pawn/resale type shops.

Hope this helps

Bruce S

[madlabs]

@brandnewb, glad you got your account issue here straightened out and thanks to the mods/admin for the help.

BN, how about starting with a more modest turbine to learn a few things and get your feet wet? Your stated goal of "the sickest" VAWT is not only unrealistic but makes me wonder if you have done the requisite research to attempt such a thing. As I said on the other site, read until your eyes bleed before ordering parts. The fact that you spent quite a bit on magnets is unfortunate. Since you have, how about building something with them that is a little less ambitious? Think of it as paying your tuition at the school of hard knocks.

If you really want to build a serious mill, start small and learn. You scoff at the size of saw blades but they have some real advantages for a first build. They come fairly true, for one thing. Obtaining a large flat plate and truing it is a non trivial thing. If you really are committed to a big first build, slow down, get the parts you really need and proceed slowly and deliberately. Otherwise it is sure to end badly and be a complete waste of time and money.

[brandnewb]

thank you Bruce,

But please let me so blund to not search for any reference regarding OSB and weather influences as I have always intend to fully shield the alternator from outside influences. And any moisture that could seep through should be dealt with the fact that the OSB I have is of type 3.

Again I could be missing the finer points but I am soooo hellbent on getting some data out if this project that I am almost beyond slowing down.

I recently made a joke that I am at freefall at speed C with a wing suit. Only to be changed direction by advice that resonates enough to make a change in the freefall path I am in at the moment.

But jokes aside, I am perfectly willing to abandon OSB3 18mm for anything else if this gives better results but then please let's keep the enclose aspect out of it for now.

[brandnewb]

@brandnewb, glad you got your account issue here straightened out and thanks to the mods/admin for the help.

BN, how about starting with a more modest turbine to learn a few things and get your feet wet? Your stated goal of "the sickest" VAWT is not only unrealistic but makes me wonder if you have done the requisite research to attempt such a thing. As I said on the other site, read until your eyes bleed before ordering parts. The fact that you spent quite a bit on magnets is unfortunate. Since you have, how about building something with them that is a little less ambitious? Think of it as paying your tuition at the school of hard knocks.

If you really want to build a serious mill, start small and learn. You scoff at the size of saw blades but they have some real advantages for a first build. They come fairly true, for one thing. Obtaining a large flat plate and truing it is a non trivial thing. If you really are committed to a big first build, slow down, get the parts you really need and proceed slowly and deliberately. Otherwise it is sure to end badly and be a complete waste of time and money.

Thank you @madlabs,

I am already at C going down real fast in terms of the alternator. I don not have the math skills yet to make a toy version of it before I go grownup scale.
For the turbine I could go a 3rd or even a 1th scale if that would make sense. Can you please elaborate how that would make sense?

[Mary B]

OSB is far to flimsy for a coil form... you would be better off having it 3d printed by someone with a large machine. Using a water proof filament(the low end filaments will absorb some H2O so not a good choice). Wood in general is to unstable and I don't care how well you water shield it moisture WILL get in there in the form of condensation.

Trust me, I have a LOT of experience with this with several boxes with delicate electronics mounted on towers! ALL have a weep hole or they would collect water.