Maximizing Copper Fill

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Hummina Shadeeba   10 MW

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Re: Maximizing Copper Fill

Post by Hummina Shadeeba » Jan 23 2022 5:47pm

Maybe it is a different unknown brand and same insulation thickness. I’ve read of other comparisons of magnet wire with thicker insulation being able to do a tighter radius without cracking.

The enamel is added before shaping according to MWS wire.
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hias9   1 kW

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Re: Maximizing Copper Fill

Post by hias9 » Jan 23 2022 6:42pm

Why should the enamel be added before shaping?
I think it makes much more sense to simply add the enamel to rectangular copper wire.
If you search for it on YouTube for example, you can see that the enamel is added to rectangular copper wire.

Hummina Shadeeba   10 MW

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Re: Maximizing Copper Fill

Post by Hummina Shadeeba » Jan 23 2022 7:05pm

Don’t know why enameled before. That’s what they said when I called asking about what they thought of possibly crushing the magnet wire I have (crushing end turns to fit the wound stator in a small motor). They called it “child’s play”.





I saw the YouTube.

larsb   10 MW

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Re: Maximizing Copper Fill

Post by larsb » Jan 25 2022 1:02pm

hias9 wrote:
Jan 23 2022 8:36am
130kph would be 1100rpm and with 16 pole pairs it would be less than 300Hz. So I doubt that skin effect is a big issue here.
Bending radius would be less than 4mm in this case. So I doubt that this would be possible with 5.5*3mm wire without damage.
So you think 5.5*1 3 in parallel would be fine or do I even need something like 5.5*0.5 6 in parallel?
I'd think it works without issue. I was surprised by the enormous toughness on the rectangular wire i bought from wires.co.uk.
Some options: https://www.wires.co.uk/acatalog/rt_ec_wire.html
The risk is more from the sharp laminations, not from the bending radius

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Re: Maximizing Copper Fill

Post by hias9 » Jan 25 2022 6:41pm

So you think that even 4mm bending radius would be no problem for 3mm thick rectangular wire?

Hummina Shadeeba   10 MW

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Re: Maximizing Copper Fill

Post by Hummina Shadeeba » Jan 25 2022 10:38pm

Surely u can do the bend and at worst the insulation cracks and u either don’t worry about it knowing the wire layered on top is insulated, or add a tiny spot of kapton tape and it’s sold for that purpose
https://www.dupont.com/content/dam/dupo ... lletin.pdf

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Re: Maximizing Copper Fill

Post by larsb » Jan 26 2022 12:58am

hias9 wrote:
Jan 25 2022 6:41pm
So you think that even 4mm bending radius would be no problem for 3mm thick rectangular wire?
I think it would work but i wouldn’t use 3mm thickness. I’ve tried 2mm and that’s stiff enough for me :wink:
Wire then need to be shaped with tools and levers, forget about pulling it into place.

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SafeDiscDancing   10 kW

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Re: Maximizing Copper Fill

Post by SafeDiscDancing » Jan 26 2022 11:02am

larsb wrote:
Jan 06 2021 12:30am
I’ve done some square wire winds, it’s really dependent on the way you shape the wire. This is a 60% winding.

Image
:bigthumb: I have done a rewind on a motor like this and can say what you did there is a true masterpiece.

I tried to do the rewind with 20 AWG and 18 AWG wire and it was a total failure as I just could not get the bends to go flat. The deeper I got into the rewind the worse things went astray so I had to abandon those attempts.

Switching to 26 AWG and it went in like butter... really easy.

So while the rectangular wire rewind is superior you need to realize most DIY folks are just not skilled enough and patient enough to do it without giving up in frustration.

Your skill is probably 1 out of 1000 in that next to no one can actually do it.

Hummina Shadeeba   10 MW

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Re: Maximizing Copper Fill

Post by Hummina Shadeeba » Jan 26 2022 12:14pm

larsb wrote:
Jan 26 2022 12:58am
hias9 wrote:
Jan 25 2022 6:41pm
So you think that even 4mm bending radius would be no problem for 3mm thick rectangular wire?
I think it would work but i wouldn’t use 3mm thickness. I’ve tried 2mm and that’s stiff enough for me :wink:
Wire then need to be shaped with tools and levers, forget about pulling it into place.
How u get such great fill? Did u model it in 3d or just try different diameter till u found what’s ideal?
My modeling was flawed and trying to measure with .1-.2mm accuracy of a stator slot, that also has epoxy was too much. Tempted to try winding a stator without epoxy and just kapton on the sharp edges and then can use the stator drawing to model abs figure what rectangular wire is ideal. With rectangular especially there’s so many options and modeling would be ideal?

That is the best winding I’ve ever seen as well. How’d u do it?!

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Re: Maximizing Copper Fill

Post by hias9 » Jan 26 2022 12:14pm

larsb wrote:
Jan 26 2022 12:58am
hias9 wrote:
Jan 25 2022 6:41pm
So you think that even 4mm bending radius would be no problem for 3mm thick rectangular wire?
I think it would work but i wouldn’t use 3mm thickness. I’ve tried 2mm and that’s stiff enough for me :wink:
Wire then need to be shaped with tools and levers, forget about pulling it into place.
Were you able to pull the 2mm in place? If I don't use 3mm, I could use 1.5mm 2 in parallel or 1mm 3 in parallel.

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Re: Maximizing Copper Fill

Post by larsb » Jan 26 2022 12:30pm

Hummina Shadeeba wrote:
Jan 26 2022 12:14pm
How u get such great fill? Did u model it in 3d or just try different diameter till u found what’s ideal?
That is the best winding I’ve ever seen as well. How’d u do it?!
I model the slot in CAD, trie some wire sizes to see which fit best, then wind it. My strategy is normally to divide the wind on two layers, after that the inevitable small mishaps grow and steal your space so any wires on the third layer is tougher to get sorted. When doing rectangular or thicker wire winds it also comes down to matching the slot height roughly evenly divided by the wire size.

As an example:
If the height of the tooth is 20mm then i try to fit my number of turns with a small added margin.
Let's say i want 8T on the bottom layer, 8T of 2.5mm wide wire is doable in theory but not likely to be wound in practice. If i loose one turn then i have 2.5mm lost space - not good enough. If the first layer is tightly wound then the second is easier to wind well.
if i instead use 2.4mm wire then 8T will be 19.2mm wide and leave 0.8mm margin. It's probably going to work. Then i wind a trial tooth to see if i can get the winding as i want it.
Last edited by larsb on Jan 26 2022 12:33pm, edited 1 time in total.

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Re: Maximizing Copper Fill

Post by larsb » Jan 26 2022 12:31pm

hias9 wrote:
Jan 26 2022 12:14pm
Were you able to pull the 2mm in place? If I don't use 3mm, I could use 1.5mm 2 in parallel or 1mm 3 in parallel.
No, not really but shaping it wasn't so hard :wink:

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Re: Maximizing Copper Fill

Post by hias9 » Jan 26 2022 12:49pm

Which tools did you use for shaping the wire?

Hummina Shadeeba   10 MW

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Re: Maximizing Copper Fill

Post by Hummina Shadeeba » Jan 26 2022 1:08pm

Wish they designed stators around a wire size for maximum fill.

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Re: Maximizing Copper Fill

Post by hias9 » Jan 26 2022 1:15pm

That’s what I am trying to do. But I have not received a quote for laser cutting and baking the laminations so far. Slots should be rectangular (not round) for rectangular wire.

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Re: Maximizing Copper Fill

Post by Hummina Shadeeba » Jan 26 2022 1:20pm

hias9 wrote:
Jan 26 2022 12:49pm
Which tools did you use for shaping the wire?
Rcgroups motor chat is a great resource and those guys are always winding and/or professional motor designers. I’ve seen collections of tools there. For really thick wire I’ve seen the stator mounted in a vice on a fixed rod and essentially dull pliers with rounded edges used. I think figuring what tools is a personal quest depending on ur method.

My method, which I’ve probably wound over 200 times now: Tie one end to a door knob and pull it on. Only tools I use are pliers (just for pulling starts n ends out of the way, a steel reinforced credit card (muni fast pass), and a polycarbonate “pusher” for pushing coils into place, and the super important plug in the center to get the transits adequately around the center. But only doing 16awg wire. (Double build and 230c rating (the best stuff available these days)).

I like to think I’m better than the ladies I see in China on YouTube at this point. Faster.
Last edited by Hummina Shadeeba on Jan 26 2022 1:24pm, edited 1 time in total.

Hummina Shadeeba   10 MW

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Re: Maximizing Copper Fill

Post by Hummina Shadeeba » Jan 26 2022 1:22pm

hias9 wrote:
Jan 26 2022 1:15pm
That’s what I am trying to do. But I have not received a quote for laser cutting and baking the laminations so far. Slots should be rectangular (not round) for rectangular wire.
To some degree doesn’t it need to be rounded and a sharp edge anywhere is a problem magnetically? A hot spot. Or maybe even the slight radius of rectangular wire is good enough?
Last edited by Hummina Shadeeba on Jan 26 2022 1:27pm, edited 2 times in total.

larsb   10 MW

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Re: Maximizing Copper Fill

Post by larsb » Jan 26 2022 1:26pm

hias9 wrote:
Jan 26 2022 12:49pm
Which tools did you use for shaping the wire?
custom made 3D printed wedges and wooden spatulas, also cut to the size needed for the stator

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Re: Maximizing Copper Fill

Post by hias9 » Jan 26 2022 2:11pm

Hummina Shadeeba wrote:
Jan 26 2022 1:22pm
hias9 wrote:
Jan 26 2022 1:15pm
That’s what I am trying to do. But I have not received a quote for laser cutting and baking the laminations so far. Slots should be rectangular (not round) for rectangular wire.
To some degree doesn’t it need to be rounded and a sharp edge anywhere is a problem magnetically? A hot spot. Or maybe even the slight radius of rectangular wire is good enough?
Did you wind the 200 stators with this technique all with round wire or also some with rectangular?
I would not make a sharp edges, but make it like the corner radius of the rectangular wire. Honestly I don’t know if this would be a problem magnetically

Hummina Shadeeba   10 MW

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Re: Maximizing Copper Fill

Post by Hummina Shadeeba » Jan 26 2022 2:29pm

I did almost all the same round 16awg (heavy build 230c rated) or 17awg for 100 two years ago. I tried the square with some samples from MWS but was disappointed. I think a longer rectangular shape would be easier/better. it was more trouble than it was worth.

A stator designed around the wire is super cool. I haven’t used this program in a while and only used it for a couple of specific questions but this software is free and easy to figure. The annoying part is doing the dxl or whatever files it needs. If u can get them into it it’s easy from there. I figure if ur designing a stator be worth running the shape through the program to figure if the corners are too sharp at least (if that’s a thing.. think it is), and figure how thick all the steel shapes need to be for the flux path to avoid saturating
https://www.emetor.com/
Last edited by Hummina Shadeeba on Jan 26 2022 2:31pm, edited 2 times in total.

larsb   10 MW

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Re: Maximizing Copper Fill

Post by larsb » Jan 26 2022 2:30pm

hias9 wrote:
Jan 26 2022 2:11pm

I would not make a sharp edges, but make it like the corner radius of the rectangular wire. Honestly I don’t know if this would be a problem magnetically
Ehrm.. If you don't know this then i don't think it's worth it to order custom laminations. Better start with some FEMM simulations first. Is emetor still for free? i thought they changed that.

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Re: Maximizing Copper Fill

Post by hias9 » Jan 26 2022 2:33pm

Not planning to order laminations now. Just requested a quote to estimate costs.
I want to try different rectangular wires first before finishing design.

Hummina Shadeeba   10 MW

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Re: Maximizing Copper Fill

Post by Hummina Shadeeba » Jan 26 2022 3:02pm

Still free. They have an updated version as well that’s not free I think.

The guy who designed it was very accessible and would help for relatively little money, maybe still.
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