ES DIY Motor Challenge

[Miles]

Useful stuff: http://www.bavaria-direct.co.za/models/motor_info.htm Mostly related to RF outrunners, though.

[HAL9000v2.0]

...
No energy input other than that to the motor itself.
...

What if there is few coils just for "intertnal needs"?

I guess we need a separate class....

How will you get decent efficiency without magnets?

viewtopic.php?p=63234#p63234

This w/o magnets and 6 phases.

[Miles]

Field coil is ok, because it will lower the efficiency...

[HAL9000v2.0]

I was thinking like this: thre phases are trensfer phases to induce magnetic field in other three phases in rotor and to react with other three phases in stator. The rotor can then be ultra light and I plan to use only 1/4th of the dia for stator coils. So basicly I can have only "thicker rim"

I know I am in "hub" class with this design that is why I did not get involved here.

[John in CR]

Could it make any sense to have both PMs and coils in the rotor in order to get the cruising efficiency of BLDC with enhanced low speed torque by activating the field coils when needed?

[HAL9000v2.0]

I want to avoid magnets so the part of rotor/rim that is outside of "stator" is not magnetic and can't pick up nails and stuff..

[jscoot]

John,

Like I said, larger motors do have an advantage. That's the reason for the kg limit. This is the non-hub motor forum

0.kg to kg should be the range that most people want to work within?

Unless some people realize they can get a much more Kw per $ in a ready made
package that will work efficiently from 100 watts to 5 Kw and weigh about 5 kg.
Besides 3 hall sensors, and controller a complete motor can be purchased for about $200. in a action or $329.95 Complete with 14 N-42-H
magnets on a balanced rotor ans a slection of stator windings to choose your Kv. A high torque motor of this type will also reduce the amount of reduction needed and will enhance over all efficiency without any expenses or losses in multi reduction chains, gears or multi speed hubs.


http://cgi.ebay.com/PMA-12-350VDC-Permanent-Magnet-Alternator-Generator-SC_W0QQitemZ280422986740QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item414a8333f4

[liveforphysics]

John,

Like I said, larger motors do have an advantage. That's the reason for the 3kg limit. This is the non-hub motor forum

0.5kg to 3kg should be the range that most people want to work within?

Unless some people realize they can get a much more Kw per $ in a ready made
package that will work efficiently from 100 watts to 5 Kw and weigh about 5 kg.
Besides 3 hall sensors, and controller a complete motor can be purchased for about $200. Complete with 14 N-42-H
magnets on a balanced rotor.

Are you showing a picture of an alternator rotor PM retrofit kit? Don't those struggle to make 80% efficiency over about 1kw?

[jscoot]

John,

Like I said, larger motors do have an advantage. That's the reason for the 3kg limit. This is the non-hub motor forum

0.5kg to 3kg should be the range that most people want to work within?

Unless some people realize they can get a much more Kw per $ in a ready made
package that will work efficiently from 100 watts to 5 Kw and weigh about 5 kg.
Besides 3 hall sensors, and controller a complete motor can be purchased for about $200. Complete with 14 N-42-H
magnets on a balanced rotor.

Are you showing a picture of an alternator rotor PM retrofit kit? Don't those struggle to make 80% efficiency over about 1kw?

A little better efficiency than Miles motor (I designed) without adding internal gears. Just a 7 to 1 ratio 219 chain drive. Not a hub motor. The od of the rotor is about 1/8" larger than the one in Miles motor but each magnet pole is about 10 times the strength with two more poles.

[liveforphysics]

This motor uses an alternator stator right? Thick laminations made of poor quality steel, poor copper fill, lam shape designed around minimizing cost rather than performance, etc etc.

Or do you have something unique and special here?

[jscoot]

This motor uses an alternator stator right? Thick laminations made of poor quality steel, poor copper fill, lam shape designed around minimizing cost rather than performance, etc etc.

Or do you have something unique and special here?

Even so, spaced powerful magnets with 0 cogging makes up for the mild steel lams. Add some silicon steel for a up grade and the efficiency gets better than it is now. You can not buy a more efficient off the shelf motor for a ebike at any price.

http://cgi.ebay.com/PMA-12-350VDC-Permanent-Magnet-Alternator-Generator-SC_W0QQitemZ280422986740QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item414a8333f4

[liveforphysics]

Enter one in the contest.

I think we will reach 10-20x the torque/weight ratio of that alternator conversion with our DIY designs.

I'm working on a 3/4" thick 10" rotor diameter motor that will a third of the weight.

[jscoot]

Enter one in the contest.

I think we will reach 10-20x the torque/weight ratio of that alternator conversion with our DIY designs.

I'm working on a 3/4" thick 10" rotor diameter motor that will a third of the weight.

Good luck with it. Every motor has it's pros and cons. Some things can be changed in commercail parts to make better motors. Starting from scratch is just too expensive and too hard for 99.9% of ebikers who wish for something better.
Stamping out silicon steel lams to be hand wound is minor compared to other options if planing to market a great ebike motor at a great price.. Where on a bike will you mount your pancake?

[enoob]

randy you do yourself no favors with this stuff.

this is a thread aimed at diy motor builds. more than a few threads were this would fit , including mine . it would be a good choice for folks that dont have a shop or the time that i have .

unless im wrong and your gonna document your build of one of these and show us the results ? if so start a thread on it like the rest here or you will do your cause more damage than good.

to be posting in this thread about where to buy an off the shelf ebike motor better than anything that can be done yourself then i will join others and begin to believe you are a shill and nothing more.

[liveforphysics]

Enter one in the contest.

I think we will reach 10-20x the torque/weight ratio of that alternator conversion with our DIY designs.

I'm working on a 3/4" thick 10" rotor diameter motor that will a third of the weight.

Good luck with it. Every motor has it's pros and cons. Some things can be changed in commercail parts to make better motors. Starting from scratch is just too expensive and too hard for 99.9% of ebikers who wish for something better.
Stamping out silicon steel lams to be hand wound is minor compared to other options if planing to market a great ebike motor at a great price.. Where on a bike will you mount your pancake?

With only 3/4" thickness, I will mount it anywhere I like on the side of the bike that happens to work out nicely for the intended chain-line to run. It's less of a protrusion than my battery pack takes up on the triangle of the frame, and much less thickness than a cyclone kit.

My motor will have no stamped steel parts in it. DIY the easy way, but with a high materials cost due to ceramic bearings and carbon fiber materials to keep weight under 3Kg.

[recumpence]

randy you do yourself no favors with this stuff.

this is a thread aimed at diy motor builds. more than a few threads were this would fit , including mine . it would be a good choice for folks that dont have a shop or the time that i have .

unless im wrong and your gonna document your build of one of these and show us the results ? if so start a thread on it like the rest here or you will do your cause more damage than good.

to be posting in this thread about where to buy an off the shelf ebike motor better than anything that can be done yourself then i will join others and begin to believe you are a shill and nothing more.

Agreed.

Just because you can buy a good "X" item, does not mean it is foolish to build your own. I had a few people on Yahoo tell me RC motors are horrible and will have the efficiency of a drill held against a wheel. I went ahead with my design using an RC motor and much good has come from it.

Let the guys tinker and leave them alone. If you have something useful to contribute, great! That is what this thread is for.

Matt

[liveforphysics]

Are any large RC motor's even made that achieve worse performance in any attribute than the converted alternator motors? They have maybe 5-10x the specific power...

It would seem like if you wanted to help guide a motor decision, the RC motors would be well above converted alternator motors.

[spinningmagnets]

Randy, I find the car alternator/PMA conversion interesting, but...it really does belong in a separate thread.

Starting from scratch is just too expensive and too hard for 99.9% of ebikers who wish for something better

Axel was kind enough to send me a rough copy of his DIY 500W RC motor build-instructions. Trust me, it is EASY (though perhaps time-consuming) and VERY cheap. Scalable to whatever power level is desired. I am anxious to see the results of others efforts from this thread. Based on past postings, these folks will certainly provide a selection of clever solutions (and after all, no single design is perfect for all applications).

a ready made package that will work efficiently from 100 watts to 5 Kw and weigh about 5 kg. Besides 3 hall sensors, and controller a complete motor can be purchased for about $200

Low RPM Permanent-Magnet-Motors are not very efficient. Low efficiency equals shorter range per a given battery pack. A $200 Bafang can be used as a 1-kW non-hub, no need to add the halls plus it weighs a lot less than 5-kg/11-lb. It would provide great range from a small battery at a low amp-draw.

Its not just the motor, 3-kW/4-HP at 24V is 125A, at 48V its 62A...which battery and controller would work?

There may be a use for this in a long-tail cargo bike (low-kV, single-stage chain, 2-kW+/3-HP+) so your competition is the Crystalyte 530X hub series. For the "sweet spot" of 500W-1500W I would recommend the alt/PMA conversion is not even close to being competitive.

[John in CR]

Are any large RC motor's even made that achieve worse performance in any attribute than the converted alternator motors? They have maybe 5-10x the specific power...

It would seem like if you wanted to help guide a motor decision, the RC motors would be well above converted alternator motors.

Isn't there a well over 90% efficiency claim somewhere about an altermotor? I remember that being my 1st question, because if true, then it's hard to argue against. Doesn't that kind of current handling potential interest you?

[jscoot]

Enter one in the contest.

I think we will reach 10-20x the torque/weight ratio of that alternator conversion with our DIY designs.

I'm working on a 3/4" thick 10" rotor diameter motor that will a third of the weight.

Good luck with it. Every motor has it's pros and cons. Some things can be changed in commercail parts to make better motors. Starting from scratch is just too expensive and too hard for 99.9% of ebikers who wish for something better.
Stamping out silicon steel lams to be hand wound is minor compared to other options if planing to market a great ebike motor at a great price.. Where on a bike will you mount your pancake?

With only 3/4" thickness, I will mount it anywhere I like on the side of the bike that happens to work out nicely for the intended chain-line to run. It's less of a protrusion than my battery pack takes up on the triangle of the frame, and much less thickness than a cyclone kit.

My motor will have no stamped steel parts in it. DIY the easy way, but with a high materials cost due to ceramic bearings and carbon fiber materials to keep weight under 3Kg.

Are you going to have any back iron or is your design coreless? I always liked the hybrid design with radial and axial flux.

http://www.greenproductdesignanddevelopment.net/component/content/article/5082

[jscoot]

Randy, I find the car alternator/PMA conversion interesting, but...it really does belong in a separate thread.

Starting from scratch is just too expensive and too hard for 99.9% of ebikers who wish for something better

Axel was kind enough to send me a rough copy of his DIY 500W RC motor build-instructions. Trust me, it is EASY (though perhaps time-consuming) and VERY cheap. Scalable to whatever power level is desired. I am anxious to see the results of others efforts from this thread. Based on past postings, these folks will certainly provide a selection of clever solutions (and after all, no single design is perfect for all applications).

a ready made package that will work efficiently from 100 watts to 5 Kw and weigh about 5 kg. Besides 3 hall sensors, and controller a complete motor can be purchased for about $200

Low RPM Permanent-Magnet-Motors are not very efficient. Low efficiency equals shorter range per a given battery pack. A $200 Bafang can be used as a 1-kW non-hub, no need to add the halls plus it weighs a lot less than 5-kg/11-lb. It would provide great range from a small battery at a low amp-draw.

Its not just the motor, 3-kW/4-HP at 24V is 125A, at 48V its 62A...which battery and controller would work?

There may be a use for this in a long-tail cargo bike (low-kV, single-stage chain, 2-kW+/3-HP+) so your competition is the Crystalyte 530X hub series. For the "sweet spot" of 500W-1500W I would recommend the alt/PMA conversion is not even close to being competitive.

To get much torque out of a high RPM rc motor will require power robbing multi reductions.
Lower RPM higher torque motors can be as high as 93% efficient with PM magnets with any size auto alternators. Since the Delco SI-10 is the most popular for obtaining numerous PM rotors available these are the most economical way to go. Even without silicon steel laminations these PM alternator/Motors can have efficiencies up in the 90% efficiency range including a single chain reduction loss and spinning the wheel. Quality magnets and design of the rotor can over come some core losses to give you better efficiency than any motors that you can buy off the shelf that are rated up to 4000 rpm. If you need a better efficiency than 90% overall to the wheel there is still the option of making silicon lams for a up grade. The weight facter of 10 lbs will not be a factor unless you like to pedal without using the motor most of the time.
A smaller custom built alternator/Motor that weighs less that 3 kg just like Miles motor with much better magnets and rotor design should fit the build here. I will post a video after mounting a cam.

I will leave your thread alone.

[enoob]

leaving it alone is your call . not what i ask.

just contribute in a constructive manner. if you see the original poster doing something that has an obvious flaw point out a better direction, help them make THEIR version better, telling folks what you have is just plain better is beside the point. from what i gather youve never tried and rc build so were does you knowelege base that they are inferior come from ? the point of this thread is -open source design of diy motors. if your gonna just bash ideas and say off the shelf drill against the tire would be better (edit from we to) I would rather you hold your tongue.

I have spent considerable time researching this and have come along way from when we first met on another forum. in that forum you treated me with tangible disrespect and so lost mine.

i dont doubt your knowledge , just your ability to share it in a constructive manner. it would be rather easy to earn my respect back, just talk to folks the same way you'd want to be talked to.

respect that fact that we are here and working towards something better. even if you've achieved the holy grail in ebikeing , good for you . help others get there on their own

personally i hope you stick around and share what you know to move ebike's along .

[jscoot]

leaving it alone is your call . not what i ask.

just contribute in a constructive manner. if you see the original poster doing something that has an obvious flaw point out a better direction, help them make THEIR version better, telling folks what you have is just plain better is beside the point. from what i gather youve never tried and rc build so were does you knowelege base that they are inferior come from ? the point of this thread is -open source design of diy motors. if your gonna just bash ideas and say off the shelf drill against the tire would be better we would rather you hold your tongue.

I have spent considerable time researching this and have come along way from when we first met on another forum. in that forum you treated me with tangible disrespect and so lost mine.

i dont doubt your knowledge , just your ability to share it in a constructive manner. it would be rather easy to earn my respect back, just talk to folks the same way you'd want to be talked to.

respect that fact that we are here and working towards something better. even if you've achieved the holy grail in ebikeing , good for you . help others get their on their own

personally i hope you stick around and share what you know to move ebike's along .

I used the first 1400 watt Aveox RC motors with a $1000. 10 to 1 CGI gearbox in 1989 a year before Aveox started production of the first brushless RC motors. The 2 lb motor/gearbox unit was a combo boat and ebike motor that was about 88% efficient using the best gearbox you could buy and the 1st two brushless rc motors sold.

I still have the two RC motorsI baught from David Palumbo.
I have been sharing what I have learned using inexpensive PM Alternators to do a much more efficient job than RC motors in a constructive manner. I am not here to disrespect anyone or anyones project. It apears the other way around but I am already used to armchair wizzards telling me there unknown facts about alternator motors that I know otherwise. Look how long it took for a few people to except Sram Dual Drive hubs for ebike use when they doubted about what I had told them about 10 years ago. Until people learn the facts on their own by building their own alternator motors and testing them on ebikes they will not ever know what is a competive ebike motor at a great price. As long as people keep making improvements on new motor designs for ebikes here surley they will have to prove to many people that the motors do as the builders say they do. Good Luck! lol with a few lightweight batteries and a video is about the best way I could think of besides competitions 1000s of miles away from each other.
As far as your comments go I think it is you who is rather rude. Did I do something to personaly offend you ? Why do I need to earn anything from you. This is today not 10 years ago.

[enoob]

ok randy lets roll.

I used the first 1400 watt Aveox RC motors with a $1000. 10 to 1 CGI gearbox in 1989 a year before Aveox started production of the first brushless RC motors. The 2 lb motor/gearbox unit was a combo boat and ebike motor that was about 88% efficient using the best gearbox you could buy and the 1st two brushless rc motors sold.
I still have the two RC motorsI baught from David Palumbo.

anything since ? or in your opinion has rc tech not evolved since 89 ?

Did I do something to personaly offend you ? Why do I need to earn anything from you. This is today not 10 years ago.

yes you did on another forum directly called me and idiot for asking a question that may have been obvious to you but would have been tremendous help to any NOOB looking at it. which is the point isnt it ? to get new people into this?

IF you want me to listen you need at least some respect. just like you wont listen to me unless you respect me . at least a little

and yes this is today not 10 years ago so ill rephrase . do you have experience with a modern rc ebike . anything less than half a decade old would do.

ooo i should add . i look forward to some video . specially if its you showing us how to put together a 90 percent + efficient altermotor . then sharing the motor so we can recreate your results.
that is how you participate in this challenge from 1000 miles away. just so you know im in a different country more than 1000 miles away from plenty of the folks here.

[enoob]

I am not here to disrespect anyone or anyones project.

i missed that one in my last post. it shows that you have no idea how you come off on paper. im gonna tell you what all the ban's and suspensions from other forums should have told you already .

you appear disrespectful, rude and flat out contemptuous of people working on ebike motors other than yours.

so you know id love to back up my accusation in the above post but you seem to have edited all your posts on that forum leaving only smiley faces. nice touch

And now unless your next post is something wildly unexpected this will be my last post concerning you in any way. the "foe" option is great in these forums and the remarkable thing here is that ive been a member of one forum or another for almost a decade and this will be only the second time i put someone on my foe list AND its the same person.