# Windings , turns or gauge for torque ?



## nozza36 (Apr 3, 2009)

As the title suggests chaps , i've been "dreaming" of a home brew 
motor design but as i want to try a pulsed motor , can anyone save me 
time by clarifying thin gauge and many turns against heavier gauge with
less turns in respect to developing high torque ?
Or is there minimal difference if they weigh the same (the winding
material that is)


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## major (Apr 4, 2008)

nozza36 said:


> As the title suggests chaps , i've been "dreaming" of a home brew
> motor design but as i want to try a pulsed motor , can anyone save me
> time by clarifying thin gauge and many turns against heavier gauge with
> less turns in respect to developing high torque ?
> ...


Hi nozza,

It relates to the volts and amps. A given mass of copper in the coil can produce a given mmf for the thermal constraints regardless of the turns/gauge ratio. But the turns/gauge ratio will determine the required source voltage and current. 

Regards,

major


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## nozza36 (Apr 3, 2009)

Many thanks for taking the time to post a reply Major !
Sorry to be a pain , but would it be possible to give me a comparison ?
i am presently building my workshop (shed , ahem)
and i want to attempt a winter build of a motor suitable for up to 60, maybe 70 mph with a 40-50 mile charge .
All snugly fitted into a specifically made frame , but using standard 
motorcycle wheels, brakes , levers ect, and i have considered 
rehousing a motorcycle gearbox as a seperate unit to emulate the feel
of a more standard setup as i think direct drive is failing to capitalise
on a good thing.
So there you are chaps , any comments , advice or problems you can muster on this subject will be greatfully recieved ; 
many thanks


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## major (Apr 4, 2008)

nozza36 said:


> Sorry to be a pain , but would it be possible to give me a comparison ?


Sorry, nozza,

You have to do your own homework. I'll throw out a word or two now and then. But I won't try to teach you motor design. That takes an engineering degree and about 10 years of experience to master. But if you want to play with magnets and wire, great. Go for it. That's how I started, like decades ago.

Good luck,

major


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## nozza36 (Apr 3, 2009)

ER, Major you posted twice and said nothing of any use , i will find out
for myself thanks , as it seems you only posted to tell me you have 
an engineering degree and i don't.


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## major (Apr 4, 2008)

nozza36 said:


> ER, Major you posted twice and said nothing of any use , i will find out
> for myself thanks , as it seems you only posted to tell me you have
> an engineering degree and i don't.


Hey nozza,

Did anyone else reply to you? And I thought my first post answered your initial posted question. It is good that you will find out for yourself. You will learn a lot more than if some engineer gives you the answers.

Good luck with your project.

major


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## markllar (Apr 28, 2009)

Wow! I just joined the forum. I thought the idea is to share knowledge and help others - am I wrong? This type of conversation makes me afraid to ask questions.


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## nozza36 (Apr 3, 2009)

markllar said:


> Wow! I just joined the forum. I thought the idea is to share knowledge and help others - am I wrong? This type of conversation makes me afraid to ask questions.


 Thanks chap , maybe we can bounce ideas off each other , i plan to begin my build this winter , so i'm just trying to establish some basic 
facts and find out what will be helpful for avoiding a major error !


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## major (Apr 4, 2008)

markllar said:


> Wow! I just joined the forum. I thought the idea is to share knowledge and help others - am I wrong? This type of conversation makes me afraid to ask questions.


Hi markllar,

Welcome to the forum. Check out my 600 plus previous posts. Have I not shared a great deal with the folks that post up questions here? And did I not provide an accurate answer to nozza's initial question? Perhaps I would have been more inclined to elaborate further if nozza had taken the time to study my response and formulate his own example and ask for my critique of his work. After all, this is diy, do it yourself. 

I think I share quite a bit here and have helped quite a few.

Regards,

major


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## nozza36 (Apr 3, 2009)

I hope to shine a light on the previous posts , my intention was not to be
insulting to Major , but to gain a clear basis for my research into a 
DC Brushless pulsed permanent motor !
I will be building this at home with few resources and am trying to save as much time and (wasted) effort as possible by "picking brains "of the more entrenched
members 
I am learning more as i go along but still find no definitive answer in the 
previous posts , anyone wanting to elaborate would be welcome to explain
PS. All replies must be in "bloke in Pub" format as i don't have as clear an 
understanding as an engineer , so examples can be more graphic than 
theoretic !


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## nozza36 (Apr 3, 2009)

I've come up with a design for my rotor , 5 rings containing 16 x 2" 
neodinium magnets each , 0.75" spacing in a 14" diameter rim.
Each magnet being 2" by 1" by 1" (80 in total)
Each ring will be advanced by 0.25"
now i just have to finalise the windings for the stator , as i want each coil to
cross the whole 5 rings for a smooth torque curve , with 5 x 1" + 4 x 0.25
spacing that makes 7" in width and 18-19" total diameter .
And of course i still don't know the answer to my initial question so i'll 
figure that out for myself !
Not to say that any advice won't be greatfully accepted chaps !


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## major (Apr 4, 2008)

nozza36 said:


> And of course i still don't know the answer to my initial question so i'll figure that out for myself !
> Not to say that any advice won't be greatfully accepted chaps !


Hey nozza,

Check out this thread and the links sited on several posts there. http://www.diyelectriccar.com/forums/showthread.php?t=31695 

My bet is that at some point you're just going have to build something and start testing. You'll never figure it out on paper ahead of time. Motor, generator, same thing. Put together a stator with a coil and a rotor with magnets. Spin it with a small constant speed motor and measure the voltage on the coil. Start experimenting with it. Change speeds. Change turns. Put more coils on it. Hook them up to a resistor so you draw current. Change the current and see what happens. Get a scope and look at the wave form. Try rectifying it. Figure out what's going on.

Then see if you can make the thing rotate as a motor using your pulse idea.

You don't have to start with a full size model. And even steal some parts from an existing motor to see how they work. Maybe a small motor from a model, or out of a discarded washing machine.

You didn't like my suggestion about an engineering degree before, so how about this approach 

Good luck,

major


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## Woodsmith (Jun 5, 2008)

Reading this thread for the first time I would like to place a defence on the side of Major's response at the begining of the thread.

His answer is correct and appropriate but from what I have gathered during my life, asking questions and getting answers that make sense depends a lot on how much understanding there is of the question by the questioner.

If one knows very little about a subject then sometimes the questions asked do not prompt the type of answer that may be expected. This is especially so if the one answering has no point of reference to place the answer so that the questioner could understand it better.

An overly simple *'Oh yes, just do x and you will get y output.*' could, and often does, prove to be totally misleading due to insufficient information, unknown assumptions and general misunderstanding. It will also not explain why _x_ gives _y_ and what the relationship is and under what conditions.

Sometimes a question can only get an answer that says *'The factors are codependent in a particular way and it would depend on many different applications of these factors and a very in depth design study at a later point in the design development to give a useful answer.'*.
This is not meant in disrespect to the questioner but would demonstrate that the question may be much more complex then the questioner realises at the time.

It is much like the question often posed about which is the best car to convert.
One could say the MR2, another could say the F250, neither is right or wrong but the answer is of no use to someone who really wants to just take 4 kids to school and has a budget of $2k.
A more correct answer is the question of 'What do you want to do and how much can you afford?'.


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## Big-Foot (Jun 8, 2008)

Pulsed motors / Stepper motors

Check this out - he has created a series that is pretty easy to understand.

Converting an Alternator to an Electric Motor

http://www.youtube.com/watch?v=rrNYIqhkTQc


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## nozza36 (Apr 3, 2009)

Major/Woodsmith , thankyou for being intelligent and understanding toward the naive , The more i learn , the more sensible my questions will become .
By next year i hope to have at least a scale model and by the following
year , a full size prototype , incorporating the motor as a stressed unit 
with a 3-5 speed gear box with clutch


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