My radial flux generator prototype

[SimonMester]

I found this place, so I'll use this for updates. ^^
So I redesigned the rotor according to advice, getting the NdFeB magnets closer together.
Next week I'll have new materials to fool around with iron cores, but for now I continue air cored and resin printed parts.
I just need it working and together to learn more for now, about wiring, adjustments of the structure and so on.

[SimonMester]

I am now stretching out my initial coils, so that the legs get swooped by the 2 different neighboring poles.
The readings on my multimeter have improved drastically!
I'd like to thank everyone in this thread: https://www.fieldlines.com/index.php/topic,150770.0.html
I know none of this is optimal, but I'm excited to be learning and get a little prototype working with the materials I have!

( Thanks everyone <3 )

[Bruce S]

Interesting.
I see 8 mags. How many coils will you be using?
What will you be mounting them in?
Do you already have a coil mounting system 3D printed? Can you share a picture of it?

Thanks
Bruce S

[SimonMester]

Interesting.
I see 8 mags. How many coils will you be using?
What will you be mounting them in?
Do you already have a coil mounting system 3D printed? Can you share a picture of it?

Thanks
Bruce S

So I initially had 12 coils in made (and made that many)
Now that I remade it to a smaller diameter I can only really fit around 8.
I'm waiting on more parts and haven't printed a mounting bit yet, but because I wanted to test things, I mounted them on a steel foil with just some hot glue so it will be easy to undo.




It works! Doesn't produce much of course due to the many inefficiencies and taped together construction but its good enough for testing purposes for now
Next week I'll have more materials, so I can do a proper setup.
Truth be told I should remake the coils... I have learned how important their shape is now.

( nobody get excited, at the moment its output is measured in miliamps and milivolts )

[MattM]

Are you going to 3D print the outer frame to hold your coils?

Perhaps you can make some rings that stack, to assemble a shell, that holds your coils with precision spacing.

[SimonMester]

Are you going to 3D print the outer frame to hold your coils?

Perhaps you can make some rings that stack, to assemble a shell, that holds your coils with precision spacing.

So I did that originally, but I faced a few problems.
For one the spacing wasn't great, so I need to remake it, but before I do that, I want to figure out how/what kind of cores I want to/ can make for them. So I assembled this more soddy version to experiment with before I go through another half a liter of UV resin for printing.



I also got some freebie, small ferrite cores, and yeah, they drastically increased the power, even in a completely suboptimal setup, literally just thrown inside some of the coils.

So I came up with an idea, that will make for some fun sciencing too!
I could get some cheap resin, and I found a cheap magnetite powder source. I could make the same size cores with different % magnetite and test on a coil just to have an idea. (And glorious science)

After all that I could make some final cores and redesign the stator in CAD and put it all together.

[JW]

This reminds me of the design with/of others here, with hard drive magnets.

[MattM]

Perhaps you can limit your printing to coil stators that hold your magnetite and create the outer shell ring with your aluminum sheet.  And instead of any inner ring, use simple endcaps that you can fasten to the stators that help hold then into place. Simple, inexpensive, and consistently reproducible.

[SimonMester]

Perhaps you can limit your printing to coil stators that hold your magnetite and create the outer shell ring with your aluminum sheet.  And instead of any inner ring, use simple endcaps that you can fasten to the stators that help hold then into place. Simple, inexpensive, and consistently reproducible.

The sheet is stainless steel, but I suppose that doesn't make much difference. Not sure what you mean by end caps?
I'm a bit low on funds to get the magnetite at the moment, even though I really want to do the experiments and found a pretty good source here. Get 6 kilos of natural magnetite powder for 37 GBP. Shipping makes it a bit more but still.
I plan on making the molds for the magnetite cores with my 3D printer, just weak ones that can be peeled away.
To be honest, I could just epoxy the coils and the cores to the metal sheet backing, I'm not sure if a strict stator structure is even necessary.

EDIT: I'm also getting a lot of mild steel bits tomorrow, and a lot more NdFeB magnets in the coming weeks. I also found a model making company who sell ceramic magnets in 2 piece packs (48x22x10mm) for 1$ each!
I got 30 packs reserved, so I'll have 60 of those magnets.

Lots of science to be done ^^

[SimonMester]

So, I have been hard at work, figuring stuff out. I'll include a new update later on iron cores, which has been quite a journey.
For now, behold, the new rotor: https://youtu.be/AB8eOKk-Hro
100x10x10mm NdFeB magnets on mild steel.

[MattM]

Looks like it rolls nice and smooth.

I used the word endcaps to describe the ends of each stator segment.  Your inner ends of each stator segment should butt together at a minimum, but it may be possible to create interlocking parts when 3D printing.  Most importantly the inward-facing ends of stator segments need to connect together to create an unbroken circuit, and your inner ring needs to carry that flux with least resistance.

Ideally your individual stator segments will allow flux to not only go through the individual segments, but for that flux to connect and return through adjacent segments, in loops.  Keeping everything rigid while allowing thermal dissipation in the stator are the first and second priority.  Highly developed designs have included interlocking inner and outer attackments.  For a homebrew design, the interlocking may be too sophisticated.  If you can create those flux loops you are further optimizing a traditional radial design but don't expect earth shattering gains from it.  While aluminum will not carry flux, it does transmit thermals.

[SimonMester]

Looks like it rolls nice and smooth.

I used the word endcaps to describe the ends of each stator segment.  Your inner ends of each stator segment should butt together at a minimum, but it may be possible to create interlocking parts when 3D printing.  Most importantly the inward-facing ends of stator segments need to connect together to create an unbroken circuit, and your inner ring needs to carry that flux with least resistance.

Ideally your individual stator segments will allow flux to not only go through the individual segments, but for that flux to connect and return through adjacent segments, in loops.  Keeping everything rigid while allowing thermal dissipation in the stator are the first and second priority.  Highly developed designs have included interlocking inner and outer attackments.  For a homebrew design, the interlocking may be too sophisticated.  If you can create those flux loops you are further optimizing a traditional radial design but don't expect earth shattering gains from it.  While aluminum will not carry flux, it does transmit thermals.

Quite accidentally I actually ended up having spaces for 12 magnets and 9 coils, so couldn't I just use this 3 phase winding?


I was thinking of rectifying it to DC and charging a battery with it as a test. (ofc will have to make sure the voltage and current are to what the battery needs)
But that is all in the future still.