Hub motor rewinding, what thickness of enamelled copper wire?

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The question was not to you, it was for mxlemming

and while we're on this subject. calculating the length of wire is just a simple task of stator width, number of slots, number of turns, number of wires. How can you not think this out for yourself.. reasons could be either you are selectively dumb or lazy and want every solution served.

But i don't think it's like this. The journey from noob to "ebike builder for a living, controller modding person" is not real. I think you try to impersonate someone you're not, could be reasons for this, nothing really outrageous with not being 100% yourself online. I wonder why?

larsb said:

jamiejackherer said:

And bare in mind, I'm running this with a 48V battery, as we should all know, lower volts and higher amps is the way to destroy any motor. If I was running higher volts, say a 60v or 72v and still the same wattage my amps would be lower. It's much harder to get 190 amps through 48v than it is to do the same at 60v..

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This is an interesting topic and i think it is not true, at least in a general sense. We are looking at the motor side so there can be some different cases

1) power to the wheel is the same --> doesn't matter what input to controller is. Power to the wheel is torque*RPM and torque depends on phase current, if phase current is the same then motor is driven the same when it comes to losses and heat.

2) motor is stalled and fed same power --> phase current limiting is done, phase current is the same, motor is driven the same

3) Motor is driven but current limiting is not taking place. Controller output corresponds to throttle input. To be able to compare in one use case i guess requested acceleration must be the same --> phase current is the same, motor is driven the same.

Would like to hear what @mxlemming has to say about these lines, if you programmed controller drive routines then this must be a known for you.

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There's a few ways to do this, but in general the throttle is read and from this a requested value is generated this can be torque (amps) or speed. Torque more common and useful for ebikes.

The controller measures the current flow. For sinusoidal (foc) this is done for all 3 phases (can be calculated from 2 phases) and transforms it to a not oscillating reference frame. For bldc square, it just measures the low side phase that's conducting and uses that.

There's then a control loop, normally PID, but can be any feedback loop with appropriate bandwidth which says current too high/low, adjust the pwm accordingly.

The pwm is then fed directly to the high side on phase for BLDC, or the inverse transform made to convert back to 3 phase for foc.

There's no need to have "current limiting" as a specific function, the current is controlled in all states of motion by the same PID. The integral term invisibly deals with the change in back EMF as speed changes.

So 1) is correct, caveat that different windings can have different resistance and the loss is I²R
2) you'd never want to explicitly drive a motor with a fixed power. You control the current and the power is what it is. At higher speeds, you may choose to limit the power drawn from the battery by by decreasing the phase current. This is typically done in a much slower control loop.
3) on all decent controllers throttle corresponds to current, not speed or voltage. In the case that throttle input exceeds either (known) controller safe values, battery safe values/... It will be limited but otherwise should be mapped straight to the current control PID loop set point.


Be nice to Jamie, he's clearly on the edge of losing his shit. I know you're safe in Sweden...

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jamiejackherer said:

Guys, I'm genuinely not interested at this stage in my game to learn everything about motor technology.

I was told that I would never be able to do it. I would fail. I don't know what I'm doing and I need to learn everything first. Was it one of you guys that said winding motors is a fine art? And a skill that not many people can achieve?

Here's an example, my first rewind attempt...
My second attempt...
My third is what you in my pics. A near perfect wind.

My fourth and latest rewind was a success first time... 2 places on the last wind that concernee me, where I only managed to get 2½ turns where everywhere else has 4!!

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So what you're saying is that you build ebikes for a living, barely know how a motor works and don't want to learn how, you just want to build a bike? You had no time and needed help but now you have had the time to rewind four motors? Then you met an expert motor winder that gave you some clues but you did it all by yourself besides that.

That third motor in the pic is not in any way near perfect.. on your fourth attempt you wound an unbalanced winding but this is a success to you?

I wouldn't want to be your customer, that's for sure.

You don't want to learn, not interested in learning but want good feedback. Do you mean good "useful"or good "positive"?

Did you come here hoping we'd all dance around your motor circle jerking? "Oooh Jamie, your windings are so tight, you must have enjoyed tapping that, can you get that fill in my motor?"

Not going to happen here. We're here to learn, understand.

This is the first thread I've seen on endless sphere that's turned nasty. And there are subsequently 2 others.

The common factor? Jamiejackherer.

Try posting your motor here:
https://www.mentalhealthforum.net/forum/

mxlemming said:

This is the first thread I've seen on endless sphere that's turned nasty. And there are subsequently 2 others.

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Perhaps first outright nasty, but I've replied to an increasing number of authors here (though worse on and perhaps influenced by social media?) that posit their own lay interpretation of physics (weight transfer, motor constants and operation, etc), and reject any conflicting proven laws or quantitative data. It seems fake news has become fake facts, and many people have adopted a guiding belief of "factual relativism".

fatty said:

mxlemming said:

This is the first thread I've seen on endless sphere that's turned nasty. And there are subsequently 2 others.

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Perhaps first outright nasty, but I've replied to an increasing number of authors here (though worse on and perhaps influenced by social media?) that posit their own lay interpretation of physics (weight transfer, motor constants and operation, etc), and reject any conflicting proven laws or quantitative data. It seems fake news has become fake facts, and many people have adopted a guiding belief of "factual relativism".

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I don't like this brave new world of doublethink. Seems increasingly normal that it gets inflicted on our lovely eco system of rational thought.

I tend to stay in this motor section. Slightly calmer. But with my big (ok, medium by everyone else's standards) pile of batteries due on Monday I'll probably start looking over there.

It looks like the OP has taken his ball and gone home.

IMHO you all did great attempting to help the guy. In fact I'd say you deserve a medal for the effort.

I'm sure you have heard the saying, "You can bring a horse water, but you can't make him drink."

By rights I should make this thread disappear, but it might be useful for someone else who isn't too damn stubborn to listen.

mxlemming said:

Try posting your motor here:
https://www.mentalhealthforum.net/forum/

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That's just abusive!!

I have borderline personality disorder and complex PTSD!!! And you think it's ok to take the piss out of people with mental health issues?

But I'm the problem of the thread?

mxlemming said:

You don't want to learn, not interested in learning but want good feedback.

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Why can't people understand, I don't have time to learn this specific stuff right now. I'm very busy. I am studying my second degree, so it's not about not wanting to learn it's about me as a person being at absolute maximum of what I have time to do.

mxlemming said:

Did you come here hoping we'd all dance around your motor circle jerking? "Oooh Jamie, your windings are so tight, you must have enjoyed tapping that, can you get that fill in my motor?"

Not going to happen here. We're here to learn, understand.

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I just wanted to suggestions on what thickness of copper wire to get. I didn't want to be told I have to learn everything about motor technology before hand. Literally just wanted others to tell me what their experiences were and what thickness of copper wire they used. Is that too difficult to understand?

Yes, having needless offspring can drive you to your wits' end. Nonetheless, it seems like a good example of your problem, not ours.

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