Motorcycle class Hub Motor

[patrickza]

Congratualtions Mark, I really think you're going to have a major impact on DIY electric bikes in the future. I've been looking at rolling chassis here in South Africa, and the prices are quite reasonable, cheaper in fact than a used dual suspension mountain bike (I'll be building an electric bicycle first to get a feel for things)!

I'm glad to see you're going with a kelly controller, even though they're more expensive I think they are top quality, at this stage I've also been looking at the 40ah thundersky cells, and will be getting a 603 so you're pretty much prototyping the whole bike for me!

Are you running regen on the motor, and if so how much power are you able to recover?

By the way, you should update your EVAlbum page, I believe the new motor and improved stats deserve to be on the page.

Cheers,

Patrick

 

[Jay64]

Who makes controllers cheaper then Kelly?

Mark, How much voltage can these motors take? I read you saying they can take 96v but then you also mentioned something about "can do over 96v". Do you know what the "safe" max is? Talking with my business partner about making an order now.

I think I'll go with a 602 for the first one. Want to go testing at the road race track, and want to be able to get out of the way of the ICE bikes.

 

[markcycle]

Who makes controllers cheaper then Kelly?

Mark, How much voltage can these motors take? I read you saying they can take 96v but then you also mentioned something about "can do over 96v". Do you know what the "safe" max is? Talking with my business partner about making an order now.

I think I'll go with a 602 for the first one. Want to go testing at the road race track, and want to be able to get out of the way of the ICE bikes.

The motors can take up to 200 volts really they are current and power limited, not voltage. If you make a slippery bike and can keep the amps below 100 continuous and pull 250-300 amps coming out of a turn your going to have one fast bike. I'm pulling 200 - 220 amps now with the 603 and she leaps off the line but with 96 volts she runs out of steam at about 55 MPH.

The big problem is getting a controller for over 136 volts but they exist though pricey.

If you want to put together a race bike, you may want a 603 with lots of voltage. A 140 volt system @ 300 amps is going to impress.

I pulling the 603 out tonight and putting in the new 602 so tomorrow starts a new round of testing.

Mark

 

[swbluto]

Do you have the technical data for the 603 and 602? Basically the RPM/V constant (or V/RPM) and the internal resistance.

If so, my simulator can be pretty easily used to predict performance at a given voltage at a given wheel size. It doesn't do "armature current limiting", though, so if you're using a Kelly control with an armature limit, the acceleration and motor currents would probably be off where the motor current exceeds the armature current limit.

So far, it seems the average accuracy of the simulator has been within 5% according to others who have used it.

Anyways, I've noticed that the power out tends to be the same for different hub motor versions when the battery current is being limited (The higher torque motors draw lower currents due to the higher internal resistance, so the power tends to equalize) at a given voltage, wheel size and battery current limit. So lower-speed performance for the 602 and 603 are probably not that much different at a given voltage and wheel size (unless you have an armature limit where both the 602 and 603's armature current is being limited, in which case the 603 would have better torque/acceleration) so a 602 would probably more advantageous if you're looking for higher speeds. Someone might want to check me on that, though.

 

[Gow864]

swbluto, where can I find your simulator i'd like to give it a try.

Thanks,
Gow.

 

[swbluto]

See below. Just to let you know, to predict your performance with these motors, you'll need to know the RPM/V or V/RPM and the internal resistance. The only motors that are currently programmed in the program are e-bike hub motors, which is kind of uninspiring for motorcyclists.

The link is in my signature.

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V V V V V

 

[markcycle]

Do you have the technical data for the 603 and 602? Basically the RPM/V constant (or V/RPM) and the internal resistance.

If so, my simulator can be pretty easily used to predict performance at a given voltage at a given wheel size. It doesn't do "armature current limiting", though, so if you're using a Kelly control with an armature limit, the acceleration and motor currents would probably be off where the motor current exceeds the armature current limit.

So far, it seems the average accuracy of the simulator has been within 5% according to others who have used it.

Anyways, I've noticed that the power out tends to be the same for different hub motor versions when the battery current is being limited (The higher torque motors draw lower currents due to the higher internal resistance, so the power tends to equalize) at a given voltage, wheel size and battery current limit. So lower-speed performance for the 602 and 603 are probably not that much different at a given voltage and wheel size (unless you have an armature limit where both the 602 and 603's armature current is being limited, in which case the 603 would have better torque/acceleration) so a 602 would probably more advantageous if you're looking for higher speeds. Someone might want to check me on that, though.

For starter
The 603 no load RPM @ 108 volts is about (+-5%) 780 RPM
I am using armature current limiting with the Kelly
The 602 is a higher RPM motor. 602 testing hopefully will happen tomorrow.

How does the simulator take eddy current losses into account do you impedance VS RPM. This motor uses a better grade of Si steel which should/does reduce eddy current losses at high RPM and reduces leakage flux also improving efficiency.

I feel hub motors get a bad rap because they are hub motors but the truth is any motor would perform poorly when made with poor materials. A hub motor manufactured with high quality material can improve the efficiency from 80% (current cheap motors) to 90% maybe even 95% by design.

I wonder if there is a market for a high quality bicycle Hub motor for a increase in cost by $150.00

Mark

 

[swbluto]

There's a Kv measurement. So, what about internal resistance? I'm sure it's not that hard for you to measure.

Anyways, the eddy current losses are taken into account via "No load current". I forgot to ask about that, too, but I assumed it was low and it doesn't seem like it affects things much except for the peak efficiency. Typically, the "cogging torque"(including eddy losses) increases with RPM with its highest at the no-load speed, so the "no load current" corresponding to the "cogging torque" at its highest is assumed. It's an approximation, but it's a fairly exact approximation since the difference in the range of "current losses"(corresponding to different cogging torques) is far dwarfed by the magnitude of the current being typically passed through the motor, and the peak efficiency is pretty much near the no-load current level anyhow, the one measure it visibly affects.

So, basically, want a somewhat ideal simulator for predicting top-end performance? Need Kv and internal resistance. Peak efficiency? Add in the no-load current. Low-end acceleration? Yeah, armature current limiting would probably need to be implemented, but oh well - I care more about speed, and a good possibly optimistic guess on acceleration is all I'm seeking.

 

[Jay64]

The motors can take up to 200 volts really they are current and power limited, not voltage. If you make a slippery bike and can keep the amps below 100 continuous and pull 250-300 amps coming out of a turn your going to have one fast bike. I'm pulling 200 - 220 amps now with the 603 and she leaps off the line but with 96 volts she runs out of steam at about 55 MPH.

The big problem is getting a controller for over 136 volts but they exist though pricey.

If you want to put together a race bike, you may want a 603 with lots of voltage. A 140 volt system @ 300 amps is going to impress.

I pulling the 603 out tonight and putting in the new 602 so tomorrow starts a new round of testing.

Mark

Well, my goal at this moment isn't to make a "race bike" out of this motor. But I do want to take it out to the race track on testing days and see what we can do with it. I want to be able to pass some people up with it and make people take notice. Sure, I won't be passing up the fastest guys with the build 1000cc bikes, but I know I can pass some people, and that in and of itself will make everyone notice. The closest track to me has a really good layout for a bike test like this. At those speeds, I might be able to do the whole track with only hitting the brakes twice. Carrying good corner speed and making it flow will enable me to pas by the guys with more power that are going too hard into the corners and having to really hit the brakes. I just want to have enough speed that I can get out of the way on the front straight. I don't want to have some newbie not realize that there is such a huge difference of speed between us when we get to the end of the straight and plow up my... (I was about to say tail pipe, but just realized that won't be there any more. ha ha) Hopefully if I can get a lot of volts into it for the speed and be able to just carry that speed through the corners, then I won't need to use that many amps on the exit of the corners.

 

[RoughRider]

how do you wanna pass anyone with 60mph on a racetrack??

even a smal 400ccm sportsbike is 0-60mph in under 5sec...

i dont think, you will pass anyone on a racetrack...maybe a bicycle...

 

[markcycle]

how do you wanna pass anyone with 60mph on a racetrack??

even a smal 400ccm sportsbike is 0-60mph in under 5sec...

i dont think, you will pass anyone on a racetrack...maybe a bicycle...

Using a MHM-603:
With 140 volts of say A123 batteries delivering 300 amps peak you'll get close to 90 MPH and I predict 0 to 60 in about 7 sec at the very worst. With the right controller and batteries on a track this motor can perform.

It will impress

Mark

 

[Jay64]

Probably the same way I pass built 1000cc race bikes with my 600cc bike. Time will tell I guess. But I guess the most important part of the plan is not only going 60mph, hence the whole discussion on how many volts the motor can take. But to be honest, you would be amazed at how a "lower powered/slower/smaller" bike can whoop up on a "bigger/faster/stronger" bike if you ride it right.

 

[RoughRider]

@jay
i agree with you...its not all about the 1000ccm

its alot about the driver...

600ccm passing a 1000ccm on a racetrack...nothing new to me


e.g. the MotoGP with the 800ccm and 240HP...they are fast, but not so fast in the corners...

the difference between 250ccm and motoGP is less than 2sec on a track


@mark
i realy like your motor...ass i have said it allready

dont get me wrong...

i think its a good motor for a comuting bike, but dont think its something for the track...


BUT...jay will try it and let us know...

 

[markcycle]

The motors can take up to 200 volts really they are current and power limited, not voltage. If you make a slippery bike and can keep the amps below 100 continuous and pull 250-300 amps coming out of a turn your going to have one fast bike. I'm pulling 200 - 220 amps now with the 603 and she leaps off the line but with 96 volts she runs out of steam at about 55 MPH.

The big problem is getting a controller for over 136 volts but they exist though pricey.

If you want to put together a race bike, you may want a 603 with lots of voltage. A 140 volt system @ 300 amps is going to impress.

I pulling the 603 out tonight and putting in the new 602 so tomorrow starts a new round of testing.

Mark

Well, my goal at this moment isn't to make a "race bike" out of this motor. But I do want to take it out to the race track on testing days and see what we can do with it. I want to be able to pass some people up with it and make people take notice. Sure, I won't be passing up the fastest guys with the build 1000cc bikes, but I know I can pass some people, and that in and of itself will make everyone notice. The closest track to me has a really good layout for a bike test like this. At those speeds, I might be able to do the whole track with only hitting the brakes twice. Carrying good corner speed and making it flow will enable me to pas by the guys with more power that are going too hard into the corners and having to really hit the brakes. I just want to have enough speed that I can get out of the way on the front straight. I don't want to have some newbie not realize that there is such a huge difference of speed between us when we get to the end of the straight and plow up my... (I was about to say tail pipe, but just realized that won't be there any more. ha ha) Hopefully if I can get a lot of volts into it for the speed and be able to just carry that speed through the corners, then I won't need to use that many amps on the exit of the corners.

Jay
I'll make you an offer in public:

You get the bike together batteries, controller and the motors/wheel is free. Put together a bike that can make this motor shine and the 603 or 602 I have right now in my hands is yours. No wait, Its got to be a LIFEPO4 battery capable of 300 amps peak and can hold the voltage at those currents.

My Thundersky pack at 200 amps drops to 80 volts (40AH pack) so I'm not capable of really stressing the motor though I've tried.

I don't like to rely on simulators and speculation real world testing is where its at.
Mark

 

[RoughRider]

what do you think of TWO motors for the track?

does it make sense, one for the front and one for the rear?

 

[Jay64]

Mark, I will be more then happy to build a bike with as much battery as I can fit. Do you want it to be all a123s? I've got a bit of a123s already, but I also have some headway cells on order 64 cells. I want to see how good those would be. After working out the difference in price etc, I'm thinking that those will be the way to go on anything but an all out race bike. If I can put the motor money towards more headway cells, then I can double my headway order, maybe I can get about another 76 cells or so. Would that be a sufficient test bed for ya? I am also still working on getting the 144v100ah Kokam cells for the race bike. I can always test your motor with those when I finally get them. Let me know if the headway cells will be sufficient for a racetrack test for you and I will make it happen. If you want it to be a123 cells it will take a little longer since I already have the orders in for the headway cells and for the kokam cells.

 

[markcycle]

Mark, I will be more then happy to build a bike with as much battery as I can fit. Do you want it to be all a123s? I've got a bit of a123s already, but I also have some headway cells on order 64 cells. I want to see how good those would be. After working out the difference in price etc, I'm thinking that those will be the way to go on anything but an all out race bike. If I can put the motor money towards more headway cells, then I can double my headway order, maybe I can get about another 76 cells or so. Would that be a sufficient test bed for ya? I am also still working on getting the 144v100ah Kokam cells for the race bike. I can always test your motor with those when I finally get them. Let me know if the headway cells will be sufficient for a racetrack test for you and I will make it happen. If you want it to be a123 cells it will take a little longer since I already have the orders in for the headway cells and for the kokam cells.

Headway cells should be fine its just a matter of having enough to minimize the voltage drop at full amps. We can talk off line about the design details and the bike being used. I'll send you my phone number so we can talk.

It's Just fantastic that you have access to a track and can help prove out the motor

Mark

 

[RoughRider]

@mark
you have a 20voltage drop at 200Amps??

thats alot...isnt it?

 

[swbluto]

Well, I'm not asking for anyone to rely on a simulator. But I do ask that some rather important technical specs be published so people can get an idea of what the heck they are getting. Even if you don't think internal resistance isn't that important, it does tell you quite a bit of how much current can safely pass through the motor, and since a torque constant is already known, that tells you quite a bit about how much force and thus acceleration you can expect to get. I can tell you, I sure as hell wouldn't be buying anything if I didn't have the ability to predict its performance for my particular application (Which could be quite different from yours), and I'm sure as heck not getting an 800 dollar plane ticket just to find out.

But, you know, if don't want technical guys like me to be your customers, go ahead and willingly exclude a segment of your market. If I were a buyer, which there's (the 'apostrophe s' representing 'is', but it seems to be transforming into 'was') some significant likelihood of being near the end of this summer, I would think you're trying to hide something when I know you know the specs and you're not divulging them, and that makes me lose quite a bit of faith. If, in the small chance you don't know how to measure the specs, then that'd make me quite wary of the available technical support.

 

[markcycle]

Well, I'm not asking for anyone to rely on a simulator. But I do ask that some rather important technical specs be published so people can get an idea of what the heck they are getting. Even if you don't think internal resistance isn't that important, it does tell you quite a bit of how much current can safely pass through the motor, and since a torque constant is already known, that tells you quite a bit about how much force and thus acceleration you can expect to get. I can tell you, I sure as hell wouldn't be buying anything if I didn't have the ability to predict its performance for my particular application (Which could be quite different from yours), and I'm sure as heck not getting an 800 dollar plane ticket just to find out.

But, you know, if don't want technical guys like me to be your customers, go ahead and willingly exclude a segment of your market. If I were a buyer, which there's (the 'apostrophe s' representing 'is', but it seems to be transforming into 'was') some significant likelihood of being near the end of this summer, I would think you're trying to hide something when I know you know the specs and you're not divulging them, and that makes me lose quite a bit of faith. If, in the small chance you don't know how to measure the specs, then that'd make me quite wary of the available technical support.

First
The 603 is in the bike, last night I lifted the rear wheel and gave you unloaded RPM. When I switch out the wheel (hopefully tonight) and have the 603 on the bench I'll measure the winding resistance using the current method using a shunt. I'm stating how much current can safely pass through the motor I don't need your simulator for that nor would I rely on it.

Second
since you are unfairly biased against hub motors (yes my opinion) I don't feel the need to work with you and since your the only one complaining I personally don't care if you buy a motor or not. Do you think based on the output of your simulator someone is going to decided to buy or not buy the 602/603 motor, not a chance. If I publish the track results and real world performance data then prospective customer will have believable data in which to make decisions.

Third
I'm going to build a track bike with Jay64, which should convince anyone the performance potential of the motor and from that real data rational people can decide if the motor is right for them. I hope early adopters of the motor will report their results with the motor and help me build confidence for the main stream.

Fourth
Do you talk nasty to everyone when you do don't get instant gratification?

Fifth
Read through this thread am I rushing anything to market? I'm test the heck out of the motor. When I found the motor was having a heating problem when running a 350 pound bike, we went back to the drawing board and did a complete design review. We delayed the introduction of the motor until I was convinced that the motor could do 200 amp off the line accelerations without a heating problem in real world traffic situations.
In my opinion your just grand standing

Mark

 

[swbluto]

It could be an instant gratification ordeal, but it seemed you were resistant to providing resistance (paradox)? As a technically minded customer, I care about that information as physics has this uncanny way of predicting things in a particular application better than off-the-rim approximation guesses - I assume you'd understand that if you excelled in physics. And my particular grudge against hub motors was dealing with crappy e-bicycle hub motors (Like the aluminum crystalyte 40x, not necessarily the steel 50x), not hub motors in general, so that doesn't apply here and your motor was definitely a possibility - relative turn-key systems are appealing, after all. Anyways, if you want to deprive a market segment of technical information due to your resistance to appeal a given representative of a subsegment, feel free to shoot yourself in the foot. I'm sure you'll still do well with the other segments of the market with your approach as you'll have another foot to stand on, but don't be surprised you'll have skeptics when you don't provide this information as it's not exactly proprietary and it's fundamental to performance and walking might not be as ideal as it could be.

The thing I don't understand is, IF you're not trying to hide anything, you don't have nothing to lose by publishing technical specs. Sure, give admonishments, "Don't trust those physics formulas, they're insane! They're created by stupid academic physicists who know nothing of the real world!", but that's not valid rationale to withhold data. Many customers won't care about the data, but there are those who need it before even considering anything. But, if you're trying to hide something, that's understandable. :wink:

 

[johnhead@frontiernet.net]

Mark,
I've been following your thread and development of this motor for a long time now. I'm a trusting but not foolish person. You will have the deposit (paypal) for MY 603 next week. I'll continue to design my Delta leaning three wheeler and give honest feedback on MY perception of the motor as soon as it is fittend and begins to propell me along the roadways of western NY. My intended use is for a daily commuter vehicle where the maximum legal top speed is 50mph and the distance is 6 miles each way.
Regards
John Head

 

[Jay64]

swbluto, I could be totally wrong here, but the way I took what he was saying wasn't that he flat out didn't want provide the information, but rather , the motor is still in the bike, and he will measure it and provide the info after he takes it out. And also it was just a low priority, but not that he expressly didn't want to do it. But then again, I could be totally wrong.

 

[Jay64]

The biggest brushless controller I could find was the 144v one. I might be stuck with that as the max volts then. I will contact steven and see if he is able to do a custom one with higher volts.

 

[markcycle]

winding resistance across any two phases .099 ohms on the 603 motor
Just done after I got back from a test ride with the new 602 motor.

Mark