Second Build

[GreenTeam]

This model im hoping to be more "polished" than all my previous attempts.

  So, on to the business end of things, here we go!

  I started by analyzing all my previous works, and came to the conclusion that I require a higher coil count because of the sizes Im working with,
Now dont get me wrong, my 6 coil designs did work,but not as intended. My best results came from a 12 coil design but I messed up the stator and have no
way to install dual rotots with out drilling through a coil or two, or three....
My third design I had the break through with pouring the stator inside a 3d printed ring with 4 bolt holes.
But that one does not spin up very well due to the fact that I cannot have it all finely tuned.

So this current design I am building is going to be another core less, and also wont have a metal backplate on the magnet rotor.
The magnet rotor does have a halbach array though, to make up for the loss of metal back plate.
The rotor consists of 32 magnets. 16 magnets with dimensions of 25x10x3mm and are in traditional N S N S arrangment and are spaced
10mm apart at the inside diamter and 20mm at the outside diameter. The other 16 magnets 20x10x2.6mm are rotated 90 degrees and inserted
exactly in between the main magnets. All magnets have been securing using teensy droplets if gorilla glue gel.
To create the halbach array, all the N magnets have two , one on each side facing it rotated 90 degrees, and these magnets are N.
So the S magnets have the S facing it, and the N have the N facing it. This is technically called "flux focusing" This was discovered not to long ago by a physicist who was
working with colliders or something. Guess that means were almost mad scientists?
The entire rotor is 150mm across and 10mm thick. The entire rotor has been 3d printed with flashforge PLA, and is surprisingly stiff. I cannot bend it, not that im very strong as it is!
I still need to print out the second rotor, but, I discovered that I dont have anough little magnets to complete the halbach array a second time. I have to buy maybe another half a dozen.

The stator itself, has been wound using 3d printed bobbins, I sd print them because I can produce them in under 20 mins! And they are resizeable.
Although, I have not figured out how to resize them into rectangles or triangles, or circles. Right now, they are trapazoid shaped, well sorta tranglish ( is that a word? )

[GreenTeam]

Since I can't use FEMM at all, to lazy to learn it. I use my own FEMM....

Gives me an idea of how wide the coil can get

[GreenTeam]

I 3d printed the stator mold to be exactly 5 mm thick. Also managed the print in place m3 bolt holes for the housing which has the exact same bolt pattern.  I am deciding if I can somehow utelize the stators from the hoverboard motors I am tearing down by somehow inserting some lamination sheets in the epoxy. Either as a few sheets of laminations as cores , or maybe all around the coils. And if I do, I am unsure how abouts to go about it. Or if I have the tooling to even cut lamination sheets narrow and straight enough. Coz, I'm already gone into paralysis through over analysis. MMM I do have one question that needs clarification though, I noticed on the hoverboard motors as I tore them down for wire and magnets n bearings etc, that the stator metal is engulfed in a plastic sheathing/shell. It is split right down the middle and comes off. What purpose does it serve? And do we need to insulate our coils from electrical steel also? Even if they are lamination coil cores? Or a few slices of steels in between the coils?

[GreenTeam]

One half of the housing is now done printing!. Just need to source out the bolts, washer and nuts to bolt the 8 mm pillow block bearing to it. And the axle will be a 8 mm shaft rod normally used for 3d printers. I chose this because I realized this is very very dense hardened steel. It can withstand the side torsion prolly alot longer than the bearings or the housing will. One issue is that I printed the housing a little to short. It has maybe two mm of clearance at best. No matter, I'll just print another stator ring and use that to increase the clearances by 4 mm. The second magnet rotor will have a built in spacer that is quite smart. And I may decrease the thickness of it by a couple of mm not sure.

[GreenTeam]

I can see now that a stator can be printed using iron pla or 316l pla filament. And the solution to make it double sided is to print a stator with slots all the way through and it still be all in one peice by having it all joined by a exterior ring. But, the basf 316l stainless steel printer filament is like four hundred dollars I think. And you cannot buy just a kg of it. You can only buy 3kg. And that is a hevvvy investment. And than if you did buy it, you are gonna need a filament storage device. One that measures how much you used, displays the humidity and temp of the filament also. And than the parts may have to be baked in a oven after to burn the pla out. There are other solutions though.

[Lusciouss]

Hello,

Could you provide information about the windings, what is the thickness of the wire and how many turns?
Thanks!

[GreenTeam]

The windings consists of many differing gauges as I used up what I had left. Two of the lightest colors are 0.33 mm @ 175 turns , four of them are 0.4 mm at 125 turns and 3 of them are bifilar 0.2mm at 125 turns and three of them are 0.5 mm at 60 turns each.

[GreenTeam]

Okkkies, here is where i am standing!!!
I am printing the second rotor, and I cannot source out the exacting magnet dimensions of the first rotor
So, the second rotor has to consist of 12 magnets with a dimension of 25x10x6mm
and the halbach array motors has to consist of 25x10x3mm. Which means the second magnet rotor is a tad bit motr porky, thats all.
No major structural design changes. All moving forward as we speak.
I acquired some M4x14mm bolts, m4 washers and m4 nuts to bolt/glue with gorilla glue gel the 8 mm pillowblock bearings to the both
gennie housings. Also, have some m3x20mm,m3 washers and m3 bolts to bolt the housing, to the spacers ( in my infinite wisdom, I forgot to factor in the a few things
when I CADed up the model on screen ) and to the stator itself. And, I found out that one of the teeth of the hoverboard motor stator is like 5 mm, which is how thick i want to
cast it!!! SO, I am going to be inserting some electrical steel, even of it adds a wee bit of grabiness. I think its a fair trade off for extra flux capture!

I do love my extened bouts of paralysis through over analysis because I am a weee bit of an overachiever and perfectionist. So, with that being said, I got traction!
But, I spun out when I thought about how to install the sheets of electrical steel to the resin pour. Its VERY crucial I get this right, since this magent rotor has the air gap spacer
built in, and, its a very very very fine gap for hand build with no high tech engineering equipement. The highest tech I got is a circle finder I 3d printed, a electronic micrometer, a metal 12 inch ruler, autocad, creality slicer, Cura Slicer, Nz-1 manual coil winder, a dremel, dremel drill press, and my work station is a plywood on a milk crate!. Plus, I knew ZIP two months ago, so im proud of what ive accoplisehd to date

[MagnetJuice]

It would be interesting to see what kind of output you are going to get out of that smorgasbord of different sizes and number of turns of wire in those coils.

One thing that I have noted is that you have learned a lot since you started posting here.

There is nothing better for learning than hands-on experience. Experimenting and trying different things is the best way to learn.

Ed

[Adriaan Kragten]

The windings consists of many differing gauges as I used up what I had left. Two of the lightest colors are 0.33 mm @ 175 turns , four of them are 0.4 mm at 125 turns and 3 of them are bifilar 0.2mm at 125 turns and three of them are 0.5 mm at 60 turns each.

If you have a 3-phase, 1-layer winding for a 16-pole generator you need twelve coils so four coils per phase. Normally all four coils of one phase are identical and connected in series. The open AC voltage generated at a certain rotational speed will be proportional to the number of turns per coil. If you use coils with a different number of turns per coil, the open AC voltage generated in one coil will differ from another coil but the coil resistance will differ too. The total open AC voltage in one phase will be the sum of the individual coil voltages. For the open voltage, you have no problems but as soon as the winding is loaded, the same current is flowing through every coil. This means that much more heat is generated in the coils with the highest resistance. This is the reason why you must use twelve identical coils if you want that the generator produces power. If the test is only done to get experience if the chosen configuration can be built mechanically, using coils with different turns per coil is no problem.

In your first post you say that you use no steel plate to which the magnets are glued but that you have a 90° turned smaller magnet in between a north and a south pole for compensation. These 90° turned magnets have some positive effect but as you are using rather thin magnets, this positive effect is limited. What counts is the total air gap in relation to the total magnet thickness in one magnetic loop.

I assume that you use two synthetic armature sheets with the stator in between. So in one magnetic loop you have two straight air gaps in between the two stator sheets, two 90° air gaps in between the three magnets in the front stator sheet and two 90° air gaps in between the three magnets in the back stator sheet. So you have totally six air gaps and also six magnets in one magnetic loop. The six air gaps have a certain total length a. For the length of the 90° air gaps you should take the average. The  six magnets have a total thickness b. If the six magnets are piled together an connected with a steel bar which isn't saturated you get the strongest flux density which is equal to the remanence Br. Br depends on the magnet quality but is about 1.2 T. The magnetic resistance of a magnet is about the same as for air. So the total air gap results in an increase of the magnetic resistance with a factor (a + b) / b. This means that the flux density in the air gap is reduced by a factor b / (a + b). This means that the flux density in the air gap becomes Br * b / (a + b). So for thin magnets and large air gaps only a small flux density in the air gap will be left.

This simple formula to calculate the flux density in the air gap can only be used if you have the same flux density in each magnet. One magnetic loop is flowing through halve of the main magnets but through a whole 90° twisted magnets. These magnets have different dimensions than the main magnets and this complicates the calculation.

[MattM]

I'm pretty impressed with 3D printing.  Would be cool to have but I am a year and a half to two years from getting something like that.  If you had a little plasma cutter you could 3D print some parts and cut out other parts where metal prints would be unnecessary.  I'd think the software would be pretty similar.

[GreenTeam]

It would be interesting to see what kind of output you are going to get out of that smorgasbord of different sizes and number of turns of wire in those coils.

One thing that I have noted is that you have learned a lot since you started posting here.

There is nothing better for learning than hands-on experience. Experimenting and trying different things is the best way to learn.

Ed

Thank you! that means alot to me! And your right to. I started with the knowledge that I can somehow create power with magnets and copper wire.
So, I stripped an extension cord and wound it up and wondered why I couldnt get any zaps from it lol, Serious! lol.
Than, I read some more and found out that reddish stuff on motors is called Shellac, NAIL POLISH! thats the secret. SO, I painted my coil that I made from
strands of a extension cord, and yet, no luck. Back to the drawing board. I read they did something called "impregnation". Im supposed to do what with my coils?
EWWWWW!!!! Plus there was no way I was gonna bake my coils dripping with fresh nail polish, I would most likely set all my hair on fire or something.
And the magnets I acquired were from cell phones I found in garbage cans, discarded in alleys, little bits from CD-roms/burners. None were the same size, but no matter,
I had magnets to work with. I just needed a magnifying lense and tweezers to place them. The nail polish came in handy there. But, no game time yet,'
More research, finds out they must be in a N S N S N arrangement. How was I to find N of a magnet? I know a compass!. But, what end if the needle points north?
I dunno! SO like a couple of hundred books later from grade 5 level to PHD thesis papers, made me realize I was totally making an idiot of myself and I didnt even know it.
My partner was so so so supportive, not saying anything. Just watching me, with love. I learned that I wouild need like maybe a couple of hundred cell phones to get the
amount of magnetic material. Yet, I still had no idear of the N level of neodymers, or Tesla, or Gauss. Or winding direction. I was an ELECTRONOOB.
Actually, I was what we in the gaming world called "Nooblishus" A noob, who doesnt know they are a noob and cant ever graduate from being a noob because they think they know it all.
Well, I had to admit I need some serious Help, and I better figure out how and where to find it. But, no one was into building little ,magnet generators for some reason.
And, than I found fieldlines.com. WOW, as I read, my face got redder by the minute, and my partner just took it all in stride, never once pointed out that maybe I could have actiually
electrocuted myself. Because by this point I went and bought a DC31-00111a stator and rotor, and had the bearings from the hoverboard. ANd the axle from one of the hoverboards surprisingly
fits the magnet rotor axle hole. I was gonna dremel it out, stuff in a pipe with a bearing on it, mount it to the edlge of my desk, freespinning, and spin away. THANK RFD^ *YP{ GAWD I didnt,
I could have wound up with a perma perm lol.

I am eternaly grateful because the way the world is going, I want to make sure I will always have power, even if I have to run for the hills or someting

[GreenTeam]

The windings consists of many differing gauges as I used up what I had left. Two of the lightest colors are 0.33 mm @ 175 turns , four of them are 0.4 mm at 125 turns and 3 of them are bifilar 0.2mm at 125 turns and three of them are 0.5 mm at 60 turns each.

If you have a 3-phase, 1-layer winding for a 16-pole generator you need twelve coils so four coils per phase. Normally all four coils of one phase are identical and connected in series. The open AC voltage generated at a certain rotational speed will be proportional to the number of turns per coil. If you use coils with a different number of turns per coil, the open AC voltage generated in one coil will differ from another coil but the coil resistance will differ too. The total open AC voltage in one phase will be the sum of the individual coil voltages. For the open voltage, you have no problems but as soon as the winding is loaded, the same current is flowing through every coil. This means that much more heat is generated in the coils with the highest resistance. This is the reason why you must use twelve identical coils if you want that the generator produces power. If the test is only done to get experience if the chosen configuration can be built mechanically, using coils with different turns per coil is no problem.

In your first post you say that you use no steel plate to which the magnets are glued but that you have a 90° turned smaller magnet in between a north and a south pole for compensation. These 90° turned magnets have some positive effect but as you are using rather thin magnets, this positive effect is limited. What counts is the total air gap in relation to the total magnet thickness in one magnetic loop.

I assume that you use two synthetic armature sheets with the stator in between. So in one magnetic loop you have two straight air gaps in between the two stator sheets, two 90° air gaps in between the three magnets in the front stator sheet and two 90° air gaps in between the three magnets in the back stator sheet. So you have totally six air gaps and also six magnets in one magnetic loop. The six air gaps have a certain total length a. For the length of the 90° air gaps you should take the average. The  six magnets have a total thickness b. If the six magnets are piled together an connected with a steel bar which isn't saturated you get the strongest flux density which is equal to the remanence Br. Br depends on the magnet quality but is about 1.2 T. The magnetic resistance of a magnet is about the same as for air. So the total air gap results in an increase of the magnetic resistance with a factor (a + b) / b. This means that the flux density in the air gap is reduced by a factor b / (a + b). This means that the flux density in the air gap becomes Br * b / (a + b). So for thin magnets and large air gaps only a small flux density in the air gap will be left.

This simple formula to calculate the flux density in the air gap can only be used if you have the same flux density in each magnet. One magnetic loop is flowing through halve of the main magnets but through a whole 90° twisted magnets. These magnets have different dimensions than the main magnets and this complicates the calculation.

Geez, never even thought about that lol. But, than again, this is just a progression of hands on learning.  maybe this one, I will actually leave the coil legs outside the stator ring so that I can connect/disconnect the phases. and see how the power levels are affected. What conclusion I did come up with during my paralysis through over analysis sesh, is this,
Since the thickness of the wire will generate heat if its to thin and the current is to high, so some of the coils that are wound with the 0.2 are bifilar. So, therefor, the thinnest is now 0.33mm.
The thickest being the 0.5mm, I thought being the heavyweights of the stator, I dont want up front, I want those on the output. So, I am going to arrange the coils, starting with the lightest gauge, and add them increasing the gauges as I go throigh the phases until I get to the 0.5mm and thats the output coils. And, the second rotor hasnt been printed yet, and I am thinking of
including 45 degree vents so that as they spin, air gets "sliced" into an onto the bottom or the top of the stator. And the 90 degree magnets dont do anything for the magnetic circuit. Its a Halbach array. Unless N of a magnet talks to the N of another magnet. I dont fully understand the science behind it, but, I suspect its got something to do with the repulsion of the fields that create the "flux focusing".

[GreenTeam]

I'm pretty impressed with 3D printing.  Would be cool to have but I am a year and a half to two years from getting something like that.  If you had a little plasma cutter you could 3D print some parts and cut out other parts where metal prints would be unnecessary.  I'd think the software would be pretty similar.

Your totally correct, there are alot of mods others have done to do just that. You can actually find stl files ( what 3d printers translate into tool path work ) that build CNC routers using dremels.
And you can even 3d print a Dremelathe LOLOL if you wanna lose an eye. Or a Dremel Drill press ( very handy ) Hmmm Im seeing a pattern here. I have come across some machines that do the same thing sans the plasma. I am not even really sure what a plasma cutter is, sounds like a blow torch or something from star trek.

My 3d printer, was actually, THE CHEAPEST made on the market at the time. Its called an Ender 3s. And even though, it was a sub 300CAD or 200 USD printer, it totally smacks around any 1k+ printer. And after I upgraded my nozzle to tungsten carbide, ill gaurantee it will give the smackdown to now 2k+ printers. The creality brand totally rocks out super hard. And the price is hard to beat. The spools of filament though, are varied in quality. I was using ANET brand, and wasnt that great. I switched to Flashforge, and WOWEEE world of differance. And, the tungsten carbide nozzle has superior thermal characteristics, which means I can really supe it up past the red line. Sometimes, its going so fast, the floor shakes a little. It zips., zaps beeeps ZZZT bep  beepity beep zzzzzzzzzt SMACK TTHUD beeep lol. It makes music of its own, and I suspect the ender series is so superior because every beep it makes I think its taking a touch measurement to make sure its pritning accurate. I say go get it hair straight back. Mine was printing with in 20 mins out of the box

[Adriaan Kragten]

And the 90 degree magnets dont do anything for the magnetic circuit. Its a Halbach array.

What you have shown in your first picture with the blue synthetic armature is something completely different as this new picture of a Halbach array. In the first picture you have used magnets size 25 * 10 * 3 mm for the main magnets and magnets size 20 * 10 * 2.6 mm for the 90° turned magnets. There is a rather large distance in between the magnets. If the front of the main magnets is in the same plane as the 2.6 mm wide side of the 90° turned magnets, it means that a 90° magnet juts out 7 mm behind the back side of the main magnets. This means that a large part of the 90° turned magnet is just in the path of the 180° turned magnetic field which flows at the back side of the armature from a north to a south pole. The 90° turned magnets therefore certainly contribute to the total magnetic flux. So I doubt if any Halbach array effect is active in your first picture.

[GreenTeam]

And the 90 degree magnets dont do anything for the magnetic circuit. Its a Halbach array.

What you have shown in your first picture with the blue synthetic armature is something completely different as this new picture of a Halbach array. In the first picture you have used magnets size 25 * 10 * 3 mm for the main magnets and magnets size 20 * 10 * 2.6 mm for the 90° turned magnets. There is a rather large distance in between the magnets. If the front of the main magnets is in the same plane as the 2.6 mm wide side of the 90° turned magnets, it means that a 90° magnet juts out 7 mm behind the back side of the main magnets. This means that a large part of the 90° turned magnet is just in the path of the 180° turned magnetic field which flows at the back side of the armature from a north to a south pole. The 90° turned magnets therefore certainly contribute to the total magnetic flux. So I doubt if any Halbach array effect is active in your first picture.

yea....I kinda suspected so, but, i kinda need to learn by doing to understand building a proper one down the road.
Since i dont have enough of the little magnets, I am using the 25x10x3 for the halbach array magnets now. And, I realized that the rest of the 25x10x3 magnets Iam using, came from
salvaging a previous learning build. And those ones were super glued two high. So the second magnet rotor now is going to be 16 N and S arranged magnets, stacked 2 high.
So,in effect, its now 25x10x6mm and the 90 degree oriented magnets are now the 25x10x3 magnets also.

So, it meant a complete redesign of the magnet rotor, which, i had realized I had mucked up on the measurements. After bolting in the bearings, the rotors would have lightly scraped the nuts inside the housing. So, the stator mold/ring I am using, I printed two more to increase the space inside the housing. It adds another 5mm. And the second magnet rotor has a built in spacer to give me a sub 1 mm air gap.

Actually, I just realized, the halbach effect is there, since the backside of the magnet rotor I already made cannot pick up even a pair of tweezers now. And other magnets dont stick either.
Its probably diminished, maybe not though. Maybe I can use an Android app like the Gauss meter or emf detector or something. But, its all moot now, because its all gorilla glued already and I didn't take any baseline measurements

[GreenTeam]

Second magnet rotor printed and assembled. But, turns out I have less magnets than I originally thought lol and now I cant do a halbach array on the second rotor.

But, I doubled up the magnet thickness to 6mm for the second rotor. And the air gap is built in the rotor, te air gap will be sub 1 mm on both sides of the stator.
AAAND catastraphic rotor failure before I even started lol.
As one rotor as you can see, has a raised disc printed into it, of 7 mm, err  maybe 6.2mm or so after PLA filament shrinkage.
So, I decided to test the spacer method i devised, and to see the air gap clearances are going to not bind up on me.
And that hurt a wee bit as I got two of my fingers caught lol. And 6 magnets jumped across the gap out of thier slots.
Gorilla glue failed me on this one. I dont understand why this happened now, when all my previous ones held. But, this is
the first time I have glued to PLA printed parts. That must be the reason, its the only variable that has changed so far.
Maybe the PLA is not porous enough? Its not smooth, not at all. Back to the drawing board, unless I can figure out why the magnets
didnt stay glued. On the metal plates, they had no problem. But, also, before I used air gaps up to 15mm, this one was maybe 6mm.
ALOT of pull there, just ask my two fingers that got in between two magnet rotors. Luckily, I am just learning on small stuff, that could have been
a broken or even severed finger.

A friendly warning to all who venture here, The risk is VERY real, VERY fast, and being magnetic, the risk is invisible.

[Adriaan Kragten]

I have built PM-armatures with much stronger magnets than yours and I have learned by experience that mounting of those magnets can be very dangerous if you don't hold them very tight and if the magnets aren't guided properly to the final position. The advantage of using a steel armature sheet is not only that there are almost no magnetic losses in this sheet when the sheet is thick enough but also that mounting of the last magnets is more secure. I would do it the following way.

Assume that I want to make an 8-pole armature according to the drawing as given in chapter 9 of my report KD 341. So 8 magnets size 30 * 20 * 10 mm have to be glued on a steel plate such that you get four north and four south poles. Assume that the four magnets of the north poles are glued first (so the south pole of the magnet is glued to the steel sheet). You have to mark the correct position of the magnets on the sheet and apply enough glue to the magnet. Mounting of these first four magnets is rather easy as they will be pulled against the sheet and as there is a large distance in between the magnets. But you need a long wooden clamp in which a magnet can be hold by two hands. So don't hold the magnet directly in your hand!

The four magnets of the south poles must be mounted in between the four magnets of the north poles. This is much more tricky as now there is much less space. The whole steel sheet has become a south pole so the last four magnets will be pulled against the sheet with a stronger force that for the first four magnets. Another problem is that a side of the magnet of a south pole will also be pulled against a side of an existing magnet of the north poles. So if the magnet is not exactly at the center line in between two north poles it will shift sideways. This last problem can be solved if a wooden or plastic sheet is made with eight rectangular holes in it which is shifted over the existing north poles. However, the holes for the south poles must have chambers for the magnet holder.

If you use no magnet holder, the magnet of a south pole can jump out of your hand, flip over 180° and can then be pulled against an existing north pole. I advice to always mark the north and south pole sides of the magnets with N and S such that after completing the gluing process it can always be verified if the magnets are mounted correctly. For magnets glued in the grooves of the armature of a radial flux PM-generator one has to mark the sides of the magnets.

If you use no steel armature sheet, the magnets of the south poles will always be pulled against the magnets of the north poles. So you should wait long enough for the glue of the first set of magnets to harden. Even if all magnets are in the correct position, the whole magnet configuration is instable so a good glue is very important. So it might also be required to use a clamp with which the position of the second set of magnets is fixated up to the glue is hardened. For a steel plate, the magnet configuration is stable if the magnets are in the correct position as all magnets are pulled against the steel sheet.

[MattM]

Does plumber glue work with PLA?

[GreenTeam]

I have no idea what plumbers glue is, and now since I bought two specialty engineering spools of metal 3d printer filament what ever budget i had is toitally blown.
No way to justify "another" tube oif glue on my desk, beside the four other types that havent been used yet lol

[MattM]

It's pretty cheap.  You may refer to it as PVC cement.  I always keep some around the home for plumbing repairs.

[GreenTeam]

Redoing my failed magnet rotor! Since these are the last I'll have of the 25x10x3 magnets. I won't have enough to anything else with them. Redesigning the rotor with much tighter tolerances for the magnets , last one had about maybe a quarter of a mm of play. This one will be quite right. And I think I may see about using epoxy as a strengthening agent. That will depend upon if I can somehow print " pour holes " in it along with "beams" or " girders " so to say to increase torsional rigidity. The last rotor was a bit flexible. The stator will be quite exciting, I have some exotic plans for that
Stay tuned!

[electrondady1]

 pl premium glue works pretty good.
 is there a steel plate beneath your blue plastic magnet locating devise?

[GreenTeam]

pl premium glue works pretty good.
 is there a steel plate beneath your blue plastic magnet locating devise?

Im unsure what my blue magnet locating device is?

[JW]

Magnetic Continuity

The completeness of a magnetic circuit, as when the armature of a horseshoe magnet is in contact with both poles. It is an attribute of a paramagnetic substance only and is identical for permanent magnets or for electro-magnets. An air space intervening between armature and magnet poles, or a space filled with any diamagnetic substance prevents continuity, although the lines of force to some extent still find their way around. The leakage is increased by discontinuity.

[GreenTeam]

Oh, the magnet rotors, no there is no steel plate.
I am creating Halbach arrays to makeup for the lack of metal plates.
Its a proven science. There are many designs that showcase them
Called Coreless and Yokeless designs, and in it, its already stated that
the PM material must be increased to make up for the loss of the back plate.
Generally, its described as a weight reducing measure, and time reducing measure
for manufacturing. But, it introduces some other issues, such as a way to secure the
halbach creating magnets. The pattern is     <SN>N<NS>S<SN> repeated all the way around.
So, the magnets in between the regular N S oriented magnets are rotated 90 degrees, and all
the N face each other, effectively repelling the flux outward, and making the magnetic pull
on the backside of the rotor almost practically non existent.

[MattM]

Can your coils go taller or is the flux path not really changed?

[GreenTeam]

You can make the coils as tall as you like, but, I am making them very close to the length and width of the coil.
ANd they are going to be trapazoid shaped. So if the magnet is 10mm thick, than at 5mm into the air gap, the useable
flux has decreased to 50 percent. The drop off rate is quite high. Since, my magnets are quite thin, I am trying to keep the coils
4-5 mm thick, and include a 0.5-1 mm gap on both sides of the magnets. And with the halbach array, the flux is shot out approx 40
percent farther, if what I read is correct. And if I interpreted it correctly.
The coils i am creating are made with 0.5mm all across, and 100 turns each


And, also, I am still researching to see if the apps I get from play store for my android phone are scientific
and accurate enough for me to be modelling the magnet rotors based upon micro tesla detected.
Right now as it stands, I detected a max of approx 1000 micro tesla on my phone, and than after I insert the
halbach array magnets, I will take another reading, and I should see a 40 percent increase in field strength.
If not, I go into mental paralysis agian lol

[GreenTeam]

The coil bobbins/former I created inside of tinkercad and fusion360.
I found it inside a cad model of a 3d printed axial flux some one built as an
experiment to use capturted rain water to spin an turbine. As I was examining
it in fusoin360, I noticed that there was coil cores inside of it, that I can reuse as
bobbins with some slight modification. And, I went a bit further and used tinkercad to
cut one bobbin in half, resized rectangles to fill in the gaps, and resized it to be 4.5 mm thick and
now I have a coil core the exact dimension of the coil holes. With this coil core shape, I am going to use
Cura 4.8 to print out 12 of these cores using ProtoPasta Magnetic Iron PLA, which is 80 percent Iron dust
and 20 percent standard PLA. Now, its not that great, not like using lamination steel, but, its a hell of alot better than
using just straight epoxy. And, the cost is only going to be maybe a few dollars. There is no actual time increase since
I am printing as I wind up coils. Also, trying to figure out how to create in tinkercad a shape that will fill the spaces in between the coils.
If I can, than I can "just press print" ( lol always wanted to say that ) and print out a stator that has the slots already built in.
Wind coils, drop into space, press in cores. And than mix up a TEENSY amount of epoxy resin!. The cost of epoxy resin is pretty steep, so with this
method, I believe I can reduce cost and construction time considerably, and get an increase in porformance,

[MattM]

The downside might be how it loses rigidity under heating.

[GreenTeam]

Its Iron.....
Another process I am going to experiment with is called "annealing".
Which is baking your 3d pla printed parts in an oven for 60 minutes at 70 degrees centigrade.
And, that melts all the layers together and makes it like extruded plastics.
And as for the damage you refer to, the PLA at best will just be "melted" out of the magnetic iron.
Also, check out the actual glassification temps of PLA, and the degaussing temps of neodymes.
THan you will see that by the time your 3d printed part starts to fail, you stopped producing power
a long time ago.....

[JW]

I am creating Halbach arrays

Interesting

"A Halbach Array is a magnetic array that produces a high magnetic field utilizing permanent magnets,
arranged with a spatially rotating magnetic field vector which has the effect of focusing and augmenting the magnetic field on one side, while cancelling it out on the other."

https://www.fieldlines.com/index.php?topic=132518.0
https://www.fieldlines.com/index.php?topic=149378.0

[GreenTeam]

Yes it is interesting!