ES DIY Motor Challenge

Electric Motors and Controllers
markobetti
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Re: ES DIY Motor Challenge

Post by markobetti » Jan 13, 2016 2:16 pm

Hi Miles,

Ugh , havent been here for long time...but i missed ES.
Ill apply for challenge with a friend from Croatia : 2,4kg motor needs to output 8.25 Nm :)
Motor we are making should be less OR EQUAL TO 2.5kg with i hope 8,25Nm
Any power limit ?
Anyway we started to work on this motor 3 months ago .
Does this in any way bends the rules or is it okay to apply ? :)

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Miles
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Re: ES DIY Motor Challenge

Post by Miles » Jan 13, 2016 2:39 pm

Hi Marko,

I had to remind myself of the rules :)

Nm/kg to exceed 0.1 * mass (kg) + 3

So, for 2.4kg:

3.24 Nm/kg * 2.4 = 7.78 Nm

Too easy :mrgreen:

jacobbloy
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Re: ES DIY Motor Challenge

Post by jacobbloy » Feb 06, 2016 6:48 am

I'm just wondering if some one here can help! Iv been working on small hub motors for a skate board, I dont want to just go an offe the shelf convention, I have recently changed for 14pole to 24n28pole but my winding seems to be off.

I have wound it in a Wye configuration it seems to not be 120deg

These are my test results.
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goa604
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Re: ES DIY Motor Challenge

Post by goa604 » Feb 12, 2016 2:12 am


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CobraJet
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Re: ES DIY Motor Challenge

Post by CobraJet » Feb 12, 2016 8:35 am

Thanks for sharing this link, that is awesome!

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Ianhill
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Re: ES DIY Motor Challenge

Post by Ianhill » Nov 03, 2016 7:34 pm

Hi all
Ive been thinking of building my own motor, I have not built one before but after a bit of research the design I feel suits my needs is a PMAsynRM or a permanent magnet assisted synchronous reluctance motor I believe these motors will run on a sensored controller ? The build would utilise samaruim magnets in the rotor and high temp winding wire so it would be more temperature resistant when pushed hard than ferrite, it would be a 12n8p configuration and be built to handle 10kw continuously.
Any tips or web pages with juicey info would be much appreciated.

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Lebowski
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Re: ES DIY Motor Challenge

Post by Lebowski » Nov 04, 2016 3:15 am

Ianhill wrote:Hi all
Ive been thinking of building my own motor, I have not built one before but after a bit of research the design I feel suits my needs is a PMAsynRM or a permanent magnet assisted synchronous reluctance motor I believe these motors will run on a sensored controller ? The build would utilise samaruim magnets in the rotor and high temp winding wire so it would be more temperature resistant when pushed hard than ferrite, it would be a 12n8p configuration and be built to handle 10kw continuously.
Any tips or web pages with juicey info would be much appreciated.
I would not run a standard sensored controller with a Reluctance Motor, the phase info needs to be twice as accurate as for a normal PM motor.

Why do you think a Reluctance Motor is best ? Because you expect high temperatures ? What kind of maximum/minimum inductance ratio are you aiming for ?

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Ianhill
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Re: ES DIY Motor Challenge

Post by Ianhill » Nov 04, 2016 12:30 pm

I'm not sure really as regards to max min inductance,I would properly go for a bldc if the pmsynrm can't be run.
I wanted it to be robust, the reason I went for the relectamce motor was cost but if i need a new controller then that argument is beat and the bldc would be cheaper still at the weighing in stage at moment.

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Ianhill
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Re: ES DIY Motor Challenge

Post by Ianhill » Nov 04, 2016 10:27 pm

In my mind I still think it will work, not a normal reluctance but a magnetic one so its synchronous just like a bldc so the rotors will turn no differently just different forces going on, but this were i come unstuck will a variable frequency drive control the throttle, is it just the relationships between the rotor/stator differ and a motor designed around 120/60° deg rotor movement per cycle work fine ???
So what I thought was the lower flux power of samarium could be overcome with added flux from a reluctance rotor giving an effective boost to power within a small motor plus it could handle high heat but being none induction there won't be much heat generated meaning large power throughput in short cycles.
Anyone with better knowledge care to shut me up ???

After lots of double checking it will work on a sensored controller the correct design mind but it has to be the synchronous type switched reluctances motors require a specialized controller for the job like mentioned.

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Ianhill
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Re: ES DIY Motor Challenge

Post by Ianhill » Nov 05, 2016 8:47 pm

Looks like the rotor design im thinking of is in a very similar form in the 2016 Chevy volt, But a 12n8p config of this type of motor has design patients own by a German company that have susccesfully won court battles over other firms trying to produce it.
Its basically a 12n8p perm mag and reluctance.
Fig1.jpg
After watching different induction cars launch, Perm mag cars launch much harder off the line than an induction motor simply can not get the torque off the line even if it goes on to out rev the perm so perm reluctance will be key for kick ass off the lights torque and massive top end if the rotor is a high speed design.

ecotech
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Re: ES DIY Motor Challenge

Post by ecotech » Nov 14, 2016 3:54 pm

How does this motor you say look like?

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Ianhill
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Re: ES DIY Motor Challenge

Post by Ianhill » Nov 14, 2016 5:38 pm

ecotech wrote:How does this motor you say look like?
I've got two motors in the design stage, one is a perm reluctance, a miniature version of the Chevy volt unit, The second motor is an bldc outrunner design ive come up with an idea to utilize scrap components that anyone can build.
Its in a design phase, its difficult finding suitable materials to make the stator laminate. While having the missus going yang yang yang in my ear.

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Re: ES DIY Motor Challenge

Post by ecotech » Nov 16, 2016 8:51 am

I find it easier to not use any iron at all but what happens is the case of the motor must have small magnetic coercivity otherwise the flux goes in the case instead of the copper wire.

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Ianhill
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Re: ES DIY Motor Challenge

Post by Ianhill » Nov 18, 2016 4:36 am

I can not understand why one would not want to use iron in a motor around the coils it amplify's the magnetic field, the only time I've seen a ironless core is in a axial generator where the magnets are spinning and the field lines are directly across the coils interacting with the copper so iron is not used because it introduces eddy losses, but in a motor where we want to create an electro magnet iron is key and making it withstand higher frequency's will give a more efficient design.

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Lebowski
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Re: ES DIY Motor Challenge

Post by Lebowski » Nov 18, 2016 5:05 am

I always had a slightly different view. Iron does not amplify the magnetic field. It concentrates it in a smaller area, thus reducing the length of wire (resistance !) necessary to make N windings. But the field through the windings comes from the permanent magnets.

I've often wondered whether small area windings would be possible in a core-less design, but with the field concentrated by some sort of lens type focussing...

Also, motors and generators are the same thing, with the same design considerations. Whether a machine acts as a motor or a generator is purely and alone determined by the electronics attached to it. If the electronics suck power out it is a generator, if electronics shove power in it is a motor. Efficiency for both setups is ruled by the same consideration: get as much back-emf as possible with the least amount of winding resistance.

Have you seen my motor building threads ? (look for Lebowski axial flux and triple stator axial flux)

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Ianhill
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Re: ES DIY Motor Challenge

Post by Ianhill » Nov 18, 2016 7:26 am

Lebowski wrote:I always had a slightly different view. Iron does not amplify the magnetic field. It concentrates it in a smaller area, thus reducing the length of wire (resistance !) necessary to make N windings. But the field through the windings comes from the permanent magnets.

I've often wondered whether small area windings would be possible in a core-less design, but with the field concentrated by some sort of lens type focussing...

Also, motors and generators are the same thing, with the same design considerations. Whether a machine acts as a motor or a generator is purely and alone determined by the electronics attached to it. If the electronics suck power out it is a generator, if electronics shove power in it is a motor. Efficiency for both setups is ruled by the same consideration: get as much back-emf as possible with the least amount of winding resistance.

Have you seen my motor building threads ? (look for Lebowski axial flux and triple stator axial flux)
You schooled me by there.
Your correct the magnetic field is concentrated not amplified and the coreless motors is just another type of motor I've never encountered, I found this article backing up your info
http://www.designworldonline.com/ironle ... cond-look/
Thanks for the Input helps educate a monkey :lol:
I'll be sure to have a read of your threads.

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Re: ES DIY Motor Challenge

Post by ecotech » Nov 19, 2016 7:25 am

Ferromagnets concetrate the flux somewhere by the principle of superposition, infinetisimal current of loops in higher magnetic permeability materials cancel and amplify the resulted forces by the magnetic field in specific regions.

For bikes and bicycles how much torque and power is the optimal?

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Re: ES DIY Motor Challenge

Post by amberwolf » Nov 19, 2016 4:45 pm

Depends on what you're doing with it and in what terrain, how you're driving the wheel with the motor, etc (direct drive, geared hub, mult-gear middrive, etc).

For instance, you'd need way more torque and power for my cargo / dog hauler projects than a typical bicycle usage, even on the flat roads here; see the links for CrazyBike2 and SB Cruiser in my signature. If I had to do what I do in hillly areas, it'd take even more.

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