Motorbike Motor

Electric Motors and Controllers
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motomoto   1 kW

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Motorbike Motor

Post by motomoto » Oct 04 2014 2:14pm

I am building a motor based on this article;

http://www.mojaladja.com/upload/elmotor ... achine.pdf

Not long ago I was set on a Emrax 207 with IP64 protection rating for my prototype supercross bike. I ordered a motor (I think) from
Roman but never really got acknowledged for the order. Email response is up to 10 days and my questions and concerns didn't get handled
to my satisfaction. I decided to move on.

After reading and understanding the Yasa presentation article several times I realized the motor size they are analyzing is the same
diameter and power I am looking for. I decided to build a motor similar to the one in the article.

I have lot's of designing to do on Solidworks but have made some progress.

basic motor.JPG
I have magnets, 11 gage square motor wire and Somaloy machinable core material coming.

http://www.mwswire.com/magnetwire_square.html

http://www.magnet4less.com/product_info ... ts_id=1188

The magnets are .6 inches longer on the inside than the Yasa and I decided to go to 14 magnets instead of 10. The only magnets I could
find were 1/4" or 1/2" thickness instead of .394" or 10 mm. I have considered 2 of the 1/4" one on top of the other to cut down on eddy
current loss but the extra magnet would start .31" away from the core face at the closest and I am not sure if it is worth it. I may want
more flywheel mass to somewhat 'tame' the torque and magnet material would at least contribute something as opposed to more backing
plate while adding even more torque. Who knows.

Finding the machinable core material was a godsend. The size I am ordering is 80 mm diameter x 40 mm tall. Perfect.

The stator area will be water cooled. The cores and all wiring will be coated in epoxy so no direct contact with liquid. The magnets
and backing plate areas will be air cooled. Somehow I will pipe clean cold air through those areas.

I am exploring the idea of running the motor at 0 degrees C or as cold as possible. The magnets are stronger and the copper has less
resistance the colder they are. Suck the air through a pile of dry ice? Yes, I am a nut. I know it.

I am only going to have enough battery for 6 minutes, the length of a supercross heat race. I don't want to cook the magnets, so a dry
ice chamber to draw the air through is being pondered.

I have a Rinehart PM100DX that I picked up on Ebay. I had the factory test it and it is all good. It weighs 20 lbs and I wish it was half that.
Oh well.
Attachments
basic motor 1.JPG
Last edited by motomoto on Nov 14 2014 12:44am, edited 1 time in total.

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Miles   100 GW

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Re: Motorbike Motor

Post by Miles » Oct 05 2014 3:35am

Look forward to following your progress, moto.

You seem to be working more on IanFiTheDwarf's scale than mine :)

I'm still working on my axial flux design. I'll get round to making it eventually......

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Miles   100 GW

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Re: Motorbike Motor

Post by Miles » Oct 05 2014 3:55am

motomoto wrote:I have considered 2 of the 1/4" one on top of the other to cut down on eddy
current loss....
I doubt if segmenting axially is going to make much difference....

What mechanical speed will this be running up to?

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motomoto   1 kW

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Re: Motorbike Motor

Post by motomoto » Oct 05 2014 10:33am

In the Yasa article just before the conclusion they have Table III where they try 7 different rotor configurations.
The more magnet laminations the less eddy current loss. If I could find .125" thick magnets I would epoxy 3 together
for each pole to get less eddy current loss.

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Miles   100 GW

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Re: Motorbike Motor

Post by Miles » Oct 05 2014 11:39am

The illustration Fig. 11 b (mislabelled as "a") shows, clearly , that the segmentation is in the radial direction.......... :P

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motomoto   1 kW

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Re: Motorbike Motor

Post by motomoto » Oct 05 2014 12:07pm

You are correct. Thanks.

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Miles   100 GW

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Re: Motorbike Motor

Post by Miles » Oct 05 2014 12:28pm

You're welcome. I didn't want you wasting time on something that probably wouldn't be effective.

Certainly, breaking the electrical connection between the magnets and the back-iron will help.

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fechter   100 GW

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Re: Motorbike Motor

Post by fechter » Oct 05 2014 1:24pm

You'll probably want a lip on the outside of the back iron to keep the magnets from flying off at high RPM. I wouldn't trust glue alone.
"One test is worth a thousand opinions"

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motomoto   1 kW

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Re: Motorbike Motor

Post by motomoto » Oct 05 2014 9:08pm

I have been thinking of putting a lip on the magnets with these aluminum plates.
They could also act as a heatsink and an air mover.
Attachments
basic motor 3.JPG

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Schlafmutze   1 W

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Re: Motorbike Motor

Post by Schlafmutze » Oct 06 2014 2:11pm

Wouldn't that cause excessive eddy currents?

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Re: Motorbike Motor

Post by halcyon_m » Oct 06 2014 4:04pm

Schlafmutze wrote:Wouldn't that cause excessive eddy currents?
I agree that the lip would be somewhat in a region with changing flux. I would suggest a CF, or kevlar wrap to get the same effect.

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Thud   100 MW

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Re: Motorbike Motor

Post by Thud » Oct 06 2014 4:26pm

Following with interest....
get some......

All information & advice provided by Thud are "Open Source" & free for personal use & distribution under the following agreement linked below.
http://creativecommons.org/licenses/by-nc-nd/3.0/

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motomoto   1 kW

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Re: Motorbike Motor

Post by motomoto » Oct 06 2014 7:55pm

I don't know. I just figured it is spinning with the magnets, so it's not cutting through those fields. I have it catching .100" of the .250" thick magnets, but I guess
it would catch some of the magnetic flux from the core/coil. How much I have no idea.

halcyon_m   10 W

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Re: Motorbike Motor

Post by halcyon_m » Oct 07 2014 12:33am

motomoto wrote:I don't know. I just figured it is spinning with the magnets, so it's not cutting through those fields. I have it catching .100" of the .250" thick magnets, but I guess
it would catch some of the magnetic flux from the core/coil. How much I have no idea.
That seems reasonable and you could always edit a trial piece if it gets warm at all.

Im curious though, where are you getting core material and how expensive is it?

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Miles   100 GW

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Re: Motorbike Motor

Post by Miles » Oct 07 2014 12:40am

halcyon_m wrote:Im curious though, where are you getting core material and how expensive is it?
http://endless-sphere.com/forums/viewto ... 30&t=38624

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fechter   100 GW

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Re: Motorbike Motor

Post by fechter » Oct 07 2014 3:24pm

Schlafmutze wrote:Wouldn't that cause excessive eddy currents?
I don't think so. The flux will be nearly static at the lip. I've seen several other motors that do this. The lip does not extend the full thickness of the magnets, maybe about 1/2 of it.
"One test is worth a thousand opinions"

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motomoto   1 kW

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Re: Motorbike Motor

Post by motomoto » Oct 07 2014 10:32pm

This is the data they sent me.
2014-09 Somaloy Prototype Material.pdf
(111.06 KiB) Downloaded 157 times
They quoted me $740 for 14 blanks of 80 mm diameter x 40 mm

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motomoto   1 kW

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Re: Motorbike Motor

Post by motomoto » Oct 19 2014 4:21pm

Is this how to wire this 12 pole 14 magnet motor?


12 pole 14 magnet.png
12 pole 14 magnet.png (126.27 KiB) Viewed 4282 times

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fechter   100 GW

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Re: Motorbike Motor

Post by fechter » Oct 20 2014 8:14pm

That seems like it should work. I'm not really an expert in this area but I know there are many different workable configurations for the same pole count. If you wind each stator pole with two layers, you can make all the interconnections around the middle, where they are shorter (saves resistance loss).
"One test is worth a thousand opinions"

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motomoto   1 kW

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Re: Motorbike Motor

Post by motomoto » Oct 23 2014 10:42pm

I guess I should state what kind of motorbike I am building this motor for. Back when I was doing the downhill bike, http://endless-sphere.com/forums/viewto ... 28&t=25193,
I posted this;
Believe me, building a dirt bike with a couple of Matt motors crosses my mind all the time. I really think I could make
a bike that could beat a 450 to the first turn and then continue to spank it for at least a couple of laps. To me, that would be
an accomplishment, even though it's not a 30 minute moto, it's a start. With batteries improving and maybe some regenerative
braking breakthroughs the time thing would increase until who knows what. Programmable throttle (torque) curves could make the bikes
super user friendly. Maybe you twist the throttle the other way and you have electronic regenerative braking at both wheels perfectly
applied. Who knows.
Well, I decided to go for it. And I always thought I could build an awesome motor if I could understand enough of the basics, so when the Emrax motor thing went sour for me, I decided
to build my own motor using the YASA article as my starting point. A 450 makes 65 hp with 35 foot pounds of torque. My motor should make 85 hp and 100 foot pounds of torque. I will
delineate everything I am doing so the experts on this forum can keep me on the right track.

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Re: Motorbike Motor

Post by ksithumper » Oct 24 2014 4:00am

For a dirt bike, anything much over 50hp leads to more wheelspin than traction on most surfaces other than deep sand. All the 450s are already well into that territory and the latest models have simple traction control systems (essentially power limiters) to help with starts. Even the very top pro riders spend more time working on the quality/linearity of the power rather than chasing more.

Not trying to rain on your parade, 80+hp on dirt may turn out to be a lot of scary fun... but it won't beat a 450 around a motocross track.
I started this game because my legs ached. Now my brain hurts.

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Re: Motorbike Motor

Post by Punx0r » Oct 24 2014 5:27am

Electric traction ought to be well suited to linear power delivery, though :)

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motomoto   1 kW

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Re: Motorbike Motor

Post by motomoto » Oct 24 2014 10:31am

Not trying to rain on your parade, 80+hp on dirt may turn out to be a lot of scary fun... but it won't beat a 450 around a motocross track.
That is what I like to hear. It truly does pump me up.

Doing what others think is impossible. That's me.

For me to build my own motor is stupid even to myself. My electronic credentials are nil. The possibility of making something that weighs 25 lbs
and makes 80 + hp is not very probable for someones first attempt at building a motor. The odds are stacked against me at every step. The biggest
joke is that I think I can build my own motor, put it in a bike and beat all the major motorcycle manufacturers.

This Mother F' er is crazy.
Last edited by motomoto on Dec 25 2014 1:20pm, edited 1 time in total.

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jansevr   1 kW

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Re: Motorbike Motor

Post by jansevr » Oct 24 2014 12:22pm

That is what I like to hear. It truly does pump me up.

Doing what others think is impossible. That's me.

For me to build my own motor is stupid even to myself. My electronic credentials are nil. The possibility of making something that weighs 25 lbs
and makes 80 + hp is not very probable for someones first attempt at building a motor. The odds are stacked against my at every step. The biggest
joke is that I think I can build my own motor, put it in a bike and beat all the major motorcycle manufacturers.
best of luck to you man! 80+ electric hp (if you can do it) will undoubtedly beat a 450 around a motocross track. im very interested in seeing how this project progresses! i love the look on peoples faces when i tell them that my 80lb downhill bike can do 50-60mph. prove the disbelievers wrong! :D

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Re: Motorbike Motor

Post by fechter » Oct 24 2014 11:16pm

There are a few good electric vs. gas motorcycle videos on youtube. Under some track conditions the electrics definitely seem to have an advantage. If traction is really the limiting factor, it may be fairly easy to work in some kind of traction control on an electric.
"One test is worth a thousand opinions"

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