# EV conversion using hub motors



## BrianWillan (Feb 22, 2008)

Greetings All

I am new here. I found this site while doing research on a EV conversion.

I have a Saturn SL1 car that I am considering doing a conversion on. From what I have gathered here, is that most people mate their electric motors to the existing transmission of the donor car. I think that is a unnecessary weight penalty and added complexity.

I came across the hub motors that bluwav systems makes http://www.bluwavsystems.com/automotive-products-wheelmotor.php and thought that was a better way to go. 

I was thinking of a 2 motor or 4 motor configuration with the option of adding a range extending generator as an option. I am not looking for crazy performance. My current car has a 100hp motor. Range should be in the 60-80km area with a max speed of 120 km/hr. Has anyone done such a conversion and if so, how is it working and what price range can I expect this to be in?

Also note that I live in Canada and need to deal with our rather frigid winters.


Thanks for your help.

Brian Willan
Oshawa, Ontario
Canada


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## the slashmaster (Feb 24, 2008)

BrianWillan said:


> Greetings All
> 
> I am new here. I found this site while doing research on a EV conversion.
> 
> ...


Now that is very interesting! I'm guessing the reason no one does this is because motors like that won't give you much torque when they are hooked directley to the wheel like that. Also they would be very heavy. If you had that much unsprung weight like that your car would probably drive like crap. Then again I'm no expert.


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## ronis108 (Dec 14, 2007)

Here is an article you might be intersetd in.

ron

http://www.treehugger.com/files/2006/08/the_hybrid_mini.php


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## the slashmaster (Feb 24, 2008)

ronis108 said:


> Here is an article you might be intersetd in.
> 
> ron
> 
> http://www.treehugger.com/files/2006/08/the_hybrid_mini.php


Hey, that's very interesting! Sounds great on paper but do they have unforseen problems that make them not worth it in the real world? I'm sure if there are any small steel parts like bolts or nuts on the street these motors will suck them right in. Now does anyone know what these motors cost?


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## the slashmaster (Feb 24, 2008)

BrianWillan said:


> Greetings All
> 
> I am new here. I found this site while doing research on a EV conversion.
> 
> ...


Just found these, do you know about them? http://www.pmlflightlink.com/motors/EW_details.html


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## BrianWillan (Feb 22, 2008)

the slashmaster said:


> Now that is very interesting! I'm guessing the reason no one does this is because motors like that won't give you much torque when they are hooked directley to the wheel like that. Also they would be very heavy. If you had that much unsprung weight like that your car would probably drive like crap. Then again I'm no expert.


As for the torque of these motors, I would dispute that you won't get much, but as you later replies with that line to the pml website, (HI-PA drive) you do get a significant amount of torque from that motor and it is times 4 in the case of the Mini QED as there are motors in each wheel.

As for your unsprung mass weight issue, that motors weights 24kg, 2 more than the original unsprung mass of the MINI wheel, so it is not that significant.

This company is based in Europe, so I will email them tomorrow to see what it would cost for that setup.

Cheers

Brian 
Oshawa, Ontario
Canada


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## the slashmaster (Feb 24, 2008)

BrianWillan said:


> As for the torque of these motors, I would dispute that you won't get much, but as you later replies with that line to the pml website, (HI-PA drive) you do get a significant amount of torque from that motor and it is times 4 in the case of the Mini QED as there are motors in each wheel.
> 
> As for your unsprung mass weight issue, that motors weights 24kg, 2 more than the original unsprung mass of the MINI wheel, so it is not that significant.
> 
> ...


Yeah would like to know what it cost. Please post in here.


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## ronis108 (Dec 14, 2007)

Here's 1 for $50,000, I thisk it is a different one though. 

http://www.brightcove.tv/title.jsp?title=742312030&channel=212469179

Here is another one I found, at the bottom of the article it says it cost about $350,000 to build. I think it could be done for less, but who an I?
http://www.caranddriver.com/reviews.../pml_flightlink_electric_mini_cooper_car_news

The motors look pretty sealed against road debris

ron


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## david85 (Nov 12, 2007)

PML flight link has one of the best systems out there, and a turnkey system from them is probably the most advanced 4 wheel propulsion system in the world right now. The catch is, a 4wd system would cost close to $90 000, and you still need batteries. For this reason, the HiPa drive mainly being deployed in limited edition high end cars.

I also tried to contact BluWav systems, but they never replied. And that seems to be the norm with all of the companies that have "wheel motors". TM4 is a subsidiary of bombardier (quebec), and they will respond, but don't take kindly to inquiries from hobbyists (I'm not the only one who found that out).

I have found nearly a dozen companies that are capable of building such a system, but none of them really want to sell them to just anyone.

Sorry to rain on some one's parade, but wheel motors are simply not offered to people like us it would seem. Technically theres nothing wrong with the idea though, it would work very well.


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## the slashmaster (Feb 24, 2008)

david85 said:


> PML flight link has one of the best systems out there, and a turnkey system from them is probably the most advanced 4 wheel propulsion system in the world right now. The catch is, a 4wd system would cost close to $90 000, and you still need batteries. For this reason, the HiPa drive mainly being deployed in limited edition high end cars.
> 
> I also tried to contact BluWav systems, but they never replied. And that seems to be the norm with all of the companies that have "wheel motors". TM4 is a subsidiary of bombardier (quebec), and they will respond, but don't take kindly to inquiries from hobbyists (I'm not the only one who found that out).
> 
> ...


Hey great answer! I didn't know it was possible to get decent power out of a wheel like that until today. You know how when you take a pc hard drive apart you have magnets way more powerful than ordinary magnets? Is that how these wheel motors have so much power? Anyone know how long wheel motors with this much power have existed?


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## BrianWillan (Feb 22, 2008)

ronis108 said:


> Here's 1 for $50,000, I thisk it is a different one though.
> 
> http://www.brightcove.tv/title.jsp?title=742312030&channel=212469179
> 
> ...


Listening to the video of the first link. The cost of the conversion is $25000 on top of the cost of the car. So if you already had a donor vehicle then....

The second link refers to the PML Mini QED (quad electric drive). The $350K price tag is astronomical. I wonder how much of that cost was the R&D for the Hi-Pa motor and other associated manufacturing costs?

It's a pitty that these hub motor companies are ignoring already interested potential buyers of their products. Basic marketing states to find an already interested group of people in something and then to create a product to meet their needs. Sales on the other hand, is creating the market first and then filling it with supply. A much harder process.

If a grassroots effort of DIY'ers reaches a critical mass, then the auto manufactures will take notice and then start giving us what we already want. 

Cheers

Brian


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## ronis108 (Dec 14, 2007)

I think it has reached a point where those with the money to do so and the people that can make it happen are getting together and making it happen. Sure there is still resistance from the auto manufacturers who wish the need to change would go away, but it is becoming more and more economic good sense to develope the EV and people are responding. So, to all you conspiracy theorist, why are LION EV, the mini's on this site, Tesla, and others not all dissapearing in the middle of the night, after a visit from oil company thugs? I hate that paranoid conspiracy theory crap! 

ron


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## the slashmaster (Feb 24, 2008)

ronis108 said:


> I think it has reached a point where those with the money to do so and the people that can make it happen are getting together and making it happen. Sure there is still resistance from the auto manufacturers who wish the need to change would go away, but it is becoming more and more economic good sense to develope the EV and people are responding. So, to all you conspiracy theorist, why are LION EV, the mini's on this site, Tesla, and others not all dissapearing in the middle of the night, after a visit from oil company thugs? I hate that paranoid conspiracy theory crap!
> 
> ron


I beg to differ, but by any chance have you ever seen a dvd called "who killed the electric car"? You might change your mind about oil company thugs if you ever do.


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## ronis108 (Dec 14, 2007)

I hate to admit, but I have not seen that movie yet, and am an embarresment to all that is green. I really must get on the ball with that one. Problem is I don't have a TV. 

ron


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## xrotaryguy (Jul 26, 2007)

If wheel motors are out, how about using a pair of large-diameter motors to drive a couple of CV axles. The would not need to be very long motors. And they don't need to turn very fast. I have looked for such a thing (at a leisurely pace), but have not found anything.


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## the slashmaster (Feb 24, 2008)

ronis108 said:


> I hate to admit, but I have not seen that movie yet, and am an embarresment to all that is green. I really must get on the ball with that one. Problem is I don't have a TV.
> 
> ron


So watch it on your pc.


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## ronis108 (Dec 14, 2007)

the slashmaster said:


> So watch it on your pc.


How would I do that? Do you have a link?

Thanks
ron


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## david85 (Nov 12, 2007)

ronis108 said:


> How would I do that? Do you have a link?
> 
> Thanks
> ron


I believe that google's video hosting has it online, sorry, I don't have the link though. Be warned, you will want to kill some one after watching it (they do not stretch the truth either, I checked).


About the wheel motor history. The first EVs powered by them were built nearly a century ago http://www.7gen.com/article-summary...sche-had-world039s-first-hybrid-100-years-ago. The more modern wheel motors that are capable of churping tires without any gear redouction were under development as early as the early 80s by TM4 according to their website (other sources agree). 

*slashmaster, *about your question of using rare earth magnets for high power motors, the short answer is yes. Its my understanding that PML uses such magnets in their brushless DC wheel motors. TM4 on the other hand, has opted for the lower cost 3 phase AC brusless system which is less susceptible to collision damage or high temperature. The AC motors are also said to be easier to scale up in size than motors with perminant magnets.


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## the slashmaster (Feb 24, 2008)

david85 said:


> I believe that google's video hosting has it online, sorry, I don't have the link though. Be warned, you will want to kill some one after watching it (they do not stretch the truth either, I checked).
> 
> 
> About the wheel motor history. The first EVs powered by them were built nearly a century ago http://www.7gen.com/article-summary...sche-had-world039s-first-hybrid-100-years-ago. The more modern wheel motors that are capable of churping tires without any gear redouction were under development as early as the early 80s by TM4 according to their website (other sources agree).
> ...


Hey nice answers you came up with! So hard drive magnets are the same kind of magnet as in those wheel motors. Hmmmmm maybe if you have a cnc machining center to build the armature and enough dead hard drives to get the magnets from you can make your own wheel motor that can chirp tires?


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## BrianWillan (Feb 22, 2008)

the slashmaster said:


> Yeah would like to know what it cost. Please post in here.


Wonders never cease, I got a reply from PML regrading my inquiry on their Hi-Pa drive motors.



> Currently the Hi-Pa drive HPD40 is the closest to production, this is the motor as used in the Volvo Re-Charge project. Currently we are in final development stages and hope to be in production by the end of this year. I expect in around 18 months time we will have the product and infrastructure in place to service the conversion market, but we cannot help at present.
> 
> Please contact us towards the end of the year when we will have a clearer idea of timescales and costs for you.


This sounds encouraging to me.

Cheers

Brian


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## david85 (Nov 12, 2007)

BrianWillan said:


> This sounds encouraging to me.
> 
> Cheers
> 
> Brian


Thanks for posting that. I heard from other sources that PML was not responding to inquiries anymore. Maybe these guys are worth keeping an eye on after all, I wonder if the cost will come down.



> Hey nice answers you came up with! So hard drive magnets are the same kind of magnet as in those wheel motors. Hmmmmm maybe if you have a cnc machining center to build the armature and enough dead hard drives to get the magnets from you can make your own wheel motor that can chirp tires?


They are similar at least. Rare earth magnets are not easy to machine because they are so brittle and vulnerable to higher temperature (I have no idea how they are made at the factory). You can get magnets already in the size that might work for building an electric motor although a wheel motor might be a challenge. What you have to remember here is that enough magnets to make a wheel motor that powerful can have enough force to lift a mid sized car. Getting two such magnets in close proximity would be disastrous, steel tools are not a good idea either. This is the advantage of the self induction motor, when its off, its really OFF!


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## BrianWillan (Feb 22, 2008)

*Re: Response from BluWav*

Greetings All

I guess the planets and moons have all aligned. I received an email response from BluWav in regards to my inquiry on their hub motors.



> Thank you for contacting BluWāv for your electric propulsion system needs. We would be happy to discuss supplying you with our products and any additional engineering service your organization might require. To get the process started I have attached a copy of our 46 kW Hub Motor System brochure. It would be wise, I believe, to schedule a personal telephone call to discuss quantity and pricing issues. Please let me know what your availability is for such a discussion.


They included a pdf file detailing their RoadRunner system designed for vehicles up to 1500kg. They use 4 of their 46 KW hub motors and a battery pack of 316V and 5.1Kwh. Pretty small pack in my view. They stated that would give a vehicle a range of 25km. Performance was peppy with a 0-60mph time of 5seconds and top speed of 75mph.

Here is a link to where you can download the pdf file. 
http://download.yousendit.com/A6EC34720E4EE0A0

Cheers

Brian Willan
Oshawa, Ontario
Canada


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## ronis108 (Dec 14, 2007)

5.3 KWH was probably just for the purpose of developing the hub motors, which is what the emphisis is here. Also that would contribute to a good 0-60 time. 46 KW per wheel would be pretty fast. I would think 4 hub motor in the right donor car could give good range and power to weight ratio. Its funny, now that I have the EV bug bite, I drive down the hwy looking at cars from the perspective of conversion material. "Hmmm, you could stuff a bunch of lithium in that baby!" "Light weight too"! 

ron


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## Thalass (Dec 28, 2007)

A possible alternative to having four hub motors would be to have two regular motors, one bolted to the rear diff, the other bolted to a diff in the front. This would allow you to use cheaper motors at the cost of having a little bit more mechanical stuff to look after (though a diff is fairly maintenance free). It's what I'm planning on doing when I start my conversion, and it's been done before at least once so I know it works  

Something that bugs me with hub motors is that the bearings have to take all that vibration and weight. I know they can build them to take it, but it just seems to me to be better to keep the motor simple and use regular wheel bearings. Just a personal opinion, really. 


Good luck with the project!


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## david85 (Nov 12, 2007)

*Re: Response from BluWav*



BrianWillan said:


> Greetings All
> 
> I guess the planets and moons have all aligned. I received an email response from BluWav in regards to my inquiry on their hub motors.
> 
> ...


Nice Going Brian! I tried twice over the course of a few months to contact them and never got a reply. I got the feeling that they were in the process of some restructuring at the time, maybe they finished aligning the planets!? I guess I'll have to try contacting them again.

As for the small battery pack, I believe that BluWav is trying to pitch itself as a hybrid systems company (online info indicates this). The motors are really intended to give front wheel drive cars parallel hybrid ability by powering the rear wheels, and in such situations a large battery is not usually needed. But the torque of a geared wheel motor is advantageous when you consider the LOWER Kw output, but higher gradibility of the system. Cost remains to be seen, but their brochures on hybrid systems seem to claim very good cost effectiveness.

I once read that a 3/4 ton truck can only transfer some 1000 Ft-lbs of torque to the road when empty before the tires break traction, I would imagine a 4 wheel burnout is possible with a system like this fitted to a smaller car.


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## ronis108 (Dec 14, 2007)

Thalass said:


> A possible alternative to having four hub motors would be to have two regular motors, one bolted to the rear diff, the other bolted to a diff in the front. This would allow you to use cheaper motors at the cost of having a little bit more mechanical stuff to look after (though a diff is fairly maintenance free). It's what I'm planning on doing when I start my conversion, and it's been done before at least once so I know it works
> 
> Something that bugs me with hub motors is that the bearings have to take all that vibration and weight. I know they can build them to take it, but it just seems to me to be better to keep the motor simple and use regular wheel bearings. Just a personal opinion, really.
> 
> ...


I like your idea. For the DIYer It would probably be less complicted than converting to 4 hub motors. I was thinking the other day on a rwd vehicle you could replace the ICE with 1 motor and have another motor in the drive shaft. It would be a matter of mounting the motor so that the connections at the motor shafts were not under stress from the motor bouncing up and down......nah, the motors would be operating at different speeds on different ends of the tranny. Oh well....

ron


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## BrianWillan (Feb 22, 2008)

*Re: Spoke To BluWav Sales Director*

As an update to my previous post about getting a response from BluWav, I spoke to their Sales and Marketing director this afternoon.

The news is not good for the DIY market for their offerings at this time. Basically their strategy is to go after the big auto makers. The gentleman also said the BluWav is an engineering and R&D company and they plan to license their technology to EV conversion companies in the future.

The cost of each hub motor and controller is $25,000 in quantities of 100 or less. Of course this does not include batteries or any of the other necessary components to do a full EV conversion. 

Well, for the time being, I can safely scratch the hub motor idea off of my conversion method list.

Cheers

Brian
Oshawa, Ontario
Canada


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## david85 (Nov 12, 2007)

$25 000 for an order of 100 or less? these guys are full of it. But I might be too if I just got a grant of 1.2 million from congress to "accellerate" my reasearch.

Man, I'm in the wrong business


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## ronis108 (Dec 14, 2007)

Last time I checked, most cars have 4 wheels. That's $100K wholesale just for the motors. Add another 20k for the donor car, more for batteries, controller, etc and a reasonable mark up for retail, and pretty soon your talking about some money.  I think I would just buy one of those cheap teslas. 

Ron


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## Ioku (Sep 27, 2007)

I think the best hope for us DIYers is going to be to DIY the wheel motor too, I think it could be done if you have the right tools. And for powerful magnets I found these, http://www.kjmagnetics.com/proddetail.asp?prod=BY0Y0X0-N52 they have all sorts of powerful magnets and the one in the link says it has a pull force of 390 LB's and is only 2 in X 2 in x 1in, so you could make some really powerful motors with these.


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## unclematt (May 11, 2008)

I have been researching hub and wheel motors for some time now, and wonder if maybe a new thread should be started with a focus on creating an open source set of plans for a DIY wheel motor. We could define our goals and then determine which could be reasonably accomplished, and which would have to be discarded. Unless off-the-shelf units can be found and utilized, there is also the problem of controllers and software and which features the software should have built in (ABS, Electronic stability control, etc).

Anyone else interested in starting a project like this? Please sound off.


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## unclematt (May 11, 2008)

I found this guy's site where he is attempting to do exactly as I suggested: make an open source hub motor:

http://www.warmlandet.com/Plone/hub-motor

If you have expertese to contribute, please register and help us make this project a reality!


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## dbc105 (Apr 30, 2008)

the link is dead. anyone else tried it? I would be interested in getting involved.

I think hub motors would be the way to go. if you look at the S10 Hybrid GM is playing with, it uses 2 wheel motors on the rear axle and the ICE is setup in front wheel drive. http://www.greencar.com/features/hubofpower/ 
if you look at the "Roller Skate" GM is talking about for the hydrogen cars it has a hub motor on each corner.

also the option of placing 2 motors back to back in place of the diff on an independent suspended car. if the motors are thin enough or maybe a common case with a left and right output shaft. I did see a similar setup on one of the hub motor sites listed in this thread. 

to be able to retro-fit to older cars would be good also. an electric '58 Vette would be cool. 

DC


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## unclematt (May 11, 2008)

http://www.warmlandet.com/

Go to this one and click on "hub motor". Don't know why that link I posted previously is not working.

I wrote the guy, but he hasn't responded back yet, so he may not be actively working on it. But that won't stop me from trying.


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## dbc105 (Apr 30, 2008)

I had also thought about one to lace into a motorcycle rear wheel would be a good idea. the ones for bicycles are all too small. this would allow the room in the frame normally used for the motor to be used for extra batteries thus more range.

DC


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## dbc105 (Apr 30, 2008)

thanks for the link. looks like he is off to a good start.

DC


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## Bowser330 (Jun 15, 2008)

In an effort to resurect this thread I would like to share some thoughts of a possible wheel motor setup...sorry to ramble on...but please comment with your thoughts...

parts needed:

Obtain four motor and controller packages from...

http://www.electricmotorsport.com/store/ems_ev_parts_motors_ac-induction.php

3900$ = 46hp and 115ftlbs (84V 550A) 89% efficient....

4 x 3900 = $15,600

Total power = 184HP & 460ftlbs

For each motor you would need a gear reduction, you can find transfer-cases from 4x4 trucks for a few hundred bucks on ebay (you can even buy gear kits to change the ratios within them).....say 1200$ for all 4...

You would have to get the frame mountings customized as well as adapter plates made, but once the fabricator has made 1, the next 3 should be much cheaper...say 1200$ for all 4 and some welding help...

total cost 18,000$ (without batteries)

thunder sky lithium packs 3.2V with 160ah each for 300$ (800A surge capable)

27 packs = 86.4 V = $8,100

86.4V x 160AH = 13.8KWH (pack only weighs 151lbs)

1000$ can get 10KW(continuous) propane generator as a range extender...(will double or triple the general range from batteries alone)(250lbs)

Total with everything is $27,100, except glider...

184Hp 460ftlbs
AWD acceleration and AWD regen braking...

The same setup can be done with only 2 of the electric motors, 92hp and 230ftlbs tq...this would cost about $16,100...(witout glider)...

Or instead of using AC motors you could use DC...

two DC motor with two controllers (1000amp to be available soon hopefully)...

$1500 DC motor x 2 = 3000$
$1500 DC controller x2 = 3000$

same gearboxes are required as in AC system...

144V worth of batteries would be 160V, 50 packs , 15,000$....more to come...


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## dr01allen (Oct 19, 2008)

the site below show a bolt on conversion for wheel motors.

http://www.poulsenhybrid.com/index.html

They don't yet sell to individuals, only through their installers. But, the idea is simple enough that some of the stock pancake motors can be configured for a similar application.


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## JRP3 (Mar 7, 2008)

Bowser330 said:


> For each motor you would need a gear reduction, you can find transfer-cases from 4x4 trucks for a few hundred bucks on ebay (you can even buy gear kits to change the ratios within them).....say 1200$ for all 4...
> 
> You would have to get the frame mountings customized as well as adapter plates made, but once the fabricator has made 1, the next 3 should be much cheaper...say 1200$ for all 4 and some welding help...


Do you know how much all those transfer cases weigh? All that weight would be better put towards batteries, not to mention all the time and money. A single transfer case adapter to mount a Chevy transmission to a Jeep transfer case will cost you $500.00, and those are mass produced.




> 184Hp 460ftlbs
> AWD acceleration and AWD regen braking...


Get a single motor AC setup and put it in an AWD vehicle. If you don't need regen use a Warp11 and save even more money. Seems as if you are going to a lot of trouble for no benefit with your plan.


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## Bowser330 (Jun 15, 2008)

you dont need transfer cases that can take that much power, chevy trucks with 300fltbs of torque is overkill...we are only talking about 50hp and 100ftlbs here...a cheaper lightweight model would be used from maybe an smaller import truck...

however I do see your point that its a lot of work. Its just another idea...

I encourage all ideas to be mentioned no matter the apparent complications because you never know how uncomplicated it can get in the future...


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## coulombKid (Jan 10, 2009)

the slashmaster said:


> Hey great answer! I didn't know it was possible to get decent power out of a wheel like that until today. You know how when you take a pc hard drive apart you have magnets way more powerful than ordinary magnets? Is that how these wheel motors have so much power? Anyone know how long wheel motors with this much power have existed?


The big mine trucks that haul 200+ tons per load have had them for decades. They would also have planetary reduction gears in each wheel which is how the automotive market will eventually shake out.


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## JRP3 (Mar 7, 2008)

Those big mine trucks have a lot of room for gearing and don't have to worry about handling and unsprung weight, I don't know if gearing can be done in a car sized wheel motor.


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## sunworksco (Sep 8, 2008)

Hub motor estimate I received from PML was $120,000.00 for 4 wheels.Unreal!!! They weigh 55lbs. each and will jack hammer your way down the street.Better to have the weight off the wheels and suspension for better handling/less wear.These wheel motors would be more suitable for a utility van with a very low floor.
Mitsubishi hub wheel design is a much more efficient one with room for the brakes in the center of the hub.
Speedway Engineering has quick-change IRS or solid axle rearends with adjustible gear ratios.They have Porsche cv hub bolt paterns for the IRS.The gear ratio can be as much as 9-1.
I have designed an ultralightweight trike ev weighing less than 600lbs. utilizing an F800ST BMW motorcycle single-sided rear end with Ducati 1098 axle/brakes.This will allow the use of http://www.blackstonetek.com/products.php carbon fiber Black Mamba wheels.
View attachment 1895


View attachment 1896


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## GTWCMT (Jan 22, 2009)

120,000 for 4 wheel motors, I think that some company lives in deram land or they want you to pay for a large part of their R&D.

Wheel hub motors are not unlike normal motors, and therefor the cost should be the same, infact there is no reason why they shouldnt cost less!
You might find with the companies that they give you a higher price just to be anoying and get rid of you.

I am new here so I might start a few threads and see what I can do.


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## JRP3 (Mar 7, 2008)

Actually since they don't have the benefit of gearing to keep amp draw low and allow better cooling, and because they will be more exposed to the elements and shock loads, they have to be more robust and water proof than regular motors, so I would think they should cost more. Obviously not the 120K that PML tried to charge.


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## MalcolmB (Jun 10, 2008)

Not seen any mention of this here – but according to the notice on PML's website they've gone into administration:

_PML Flightlink Limited - in Administration
EM Shires and RW Birchall were appointed as Joint Administrators of PML Flightlink Limited on 28th November 2008 to manage its affairs, business and property. EM Shires and RW Birchall contract as agents of the Company without personal liability. EM Shires and RW Birchall are licensed to act as insolvency practitioners by the Institute of Chartered Accountants in England and Wales.
_


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## GTWCMT (Jan 22, 2009)

JRP3 said:


> Actually since they don't have the benefit of gearing to keep amp draw low and allow better cooling, and because they will be more exposed to the elements and shock loads, they have to be more robust and water proof than regular motors, so I would think they should cost more. Obviously not the 120K that PML tried to charge.


The amp draw would be based on the weight of the EV in relation to the speed/acceleration, if you have four motors, you would not draw 4 times the power to do the same work, you would draw four time less power as each wheel would share the weight. - this is why many of the wheel hub systems seem to have under powered power packs and such range.

Better cooling, we thats down to design - take F1 car disc coolers, problem solved.
Shock loads will be on the bearings, but then is equally shared between the four. they do not need to be any more robust and we would only be talking a slight cost in materials in the casing - an extra few KG of alloy.
Dont forget there is the guy with the all nylon motor who has not heat problems and a very efficient motor.


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## GTWCMT (Jan 22, 2009)

MalcolmB said:


> Not seen any mention of this here – but according to the notice on PML's website they've gone into administration:
> 
> _PML Flightlink Limited - in Administration_
> _EM Shires and RW Birchall were appointed as Joint Administrators of PML Flightlink Limited on 28th November 2008 to manage its affairs, business and property. EM Shires and RW Birchall contract as agents of the Company without personal liability. EM Shires and RW Birchall are licensed to act as insolvency practitioners by the Institute of Chartered Accountants in England and Wales._


dont they supply the motors etc for the lightenting car's! so that another EV back to the drawing board or off by the look of it. maybe that 120,000 was the money they needed to keep the company afloat?


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## JRP3 (Mar 7, 2008)

GTWCMT said:


> The amp draw would be based on the weight of the EV in relation to the speed/acceleration, if you have four motors, you would not draw 4 times the power to do the same work, you would draw four time less power as each wheel would share the weight. - this is why many of the wheel hub systems seem to have under powered power packs and such range.


 True the total load would be shared, but the total energy to move the vehicle remains the same, with 1 motor or 4, so there should be no gain in efficiency. The range claims for wheel motor setups are mostly unsubstantiated from what I've seen, PML never demonstrated their claims.


> Better cooling, we thats down to design - take F1 car disc coolers, problem solved.


 How do they work? Will they work on a sealed motor since I assume they work on open rotors?


> Shock loads will be on the bearings, but then is equally shared between the four.


 Not true, the whole motor is subjected to shock loading, the shock doesn't just stop at the bearing, it travels through the entire motor and all unsprung components. A single traction motor is isolated by the suspension.


> they do not need to be any more robust


 Yes they do.


> and we would only be talking a slight cost in materials in the casing - an extra few KG of alloy.


 It will always cost more to build 4 individual units than one larger unit, not to mention wiring and controlling those units, and the fact that they need to be completely waterproof.


> Dont forget there is the guy with the all nylon motor who has not heat problems and a very efficient motor.


Never heard of that.
I'm not saying wheel motors can't work but to expect 4 wheel motors to be cheaper than 1 large traction motor is unrealistic.


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## kabalah70 (Jan 25, 2009)

*PML Flightlink*

PML Flightlink's $120,000 quote was a statement saying that they would cost that much if you were able to buy one today, being hand assembled. They are not for sale. As for the viability of them just look at their new website. www.*hipadrive*.com They have regen braking down to zero built in, that means no hydromechanical brakes are needed reducing unsprung weight. Volvo and Ford think it is a good idea, so  to all you naysayers.


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## GTWCMT (Jan 22, 2009)

Sorry, JRP3 I did not mean they would draw less power than one motor I meant that they would draw the same power from all four, but with brushless being more efficient there is a little saving to be had; not to mention the lesser mecanical friction.

Well I would assume ramed case air cooling using ducting.

Yes you are correct, but as the load is shared the points of shock are more wide spread.

I was stating the costs on a one to one basis not one four.

kabalah70 If they are using a motor break system, dosent that mean that they would require power to torque lock the motor? many of the hub systems that I have seen use a shoe type brake system on the inner case or a disc system thats built internal. I have seen one system that has an external disc system that uses a 90o angle disc and a outer arm with the caliper mounted. It kind of made it look like a swing arm off a motor bike.


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## unclematt (May 11, 2008)

*Re: PML Flightlink*



kabalah70 said:


> PML Flightlink's $120,000 quote was a statement saying that they would cost that much if you were able to buy one today, being hand assembled. They are not for sale. As for the viability of them just look at their new website. www.*hipadrive*.com They have regen braking down to zero built in, that means no hydromechanical brakes are needed reducing unsprung weight. Volvo and Ford think it is a good idea, so  to all you naysayers.


I was one of the first people on this site to promote the Hipa drive system, but not if they aren't made available to the public by themselves or in an available car that can be purchased by the non-wealthy. If they make that happen I will be one happy camper, but if they are indeed in financial difficulty, that won't be happening. The presence of a web site is ZERO indicator of a company's ability to go forward. Their design is a THING OF BEAUTY, but their execution of a failed business model is not, much like Chorus Motors & Raser Technologie's motor, and is disappointing to say the least. When a product is made available to the public for a reasonable price, get back to me...


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## kabalah70 (Jan 25, 2009)

*PML Flightlink*

I don't know much about this stuff so bear with me if I get it wrong.
In regards to the braking question,
To my knowledge they don't do much of anything other than turn the motor into a generator and the fact of cutting the magnetic line of flux to produce power slows the car to a standstill. My understading of these motors is that the torque they produce in acceleration is almost equal to the torque they produce in braking, and it is regenerative braking at that.
Their design has the inverter built into the hub motor, it is a pancake motor mind you not an induction motor, so brushes are involved. Supposedly, this allows for a smoother current flow than an induction motor. Anyway....
In regards to having them available to the public...the fact that they are linked up with Volvo and the parent Ford, means I think this will be 
proprietary property that you will only see in future Ford and Volvo products, imho. Seems that this is the way of all the good EV tech out their. Altairnano has the best battery on the market for EV being able to REPLACE ICE vehicles for cross-country travel since their batteries can recharge so quickly and still last the life of a car. I hope Altairnano gets 'in bed' with Ford/Volvo because these two techs are the wave of the future. At least The Lightning Car Company had the vision to see that. Hopefully, Ford/Volvo will and we can all have a car with these two techs instead of just the filthy rich.


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## unclematt (May 11, 2008)

Altairnano business model is much like raser and Chorus business model in that they want to license their technology instead of just manufacturing it themselves. Its pathetic. A123 batteries have been in production for a long time now, even though Altairnano was way ahead of them at one point when it came to design and patents.

Again, its this failed idea that you don't have to manufacture a product to get rich off that product. I was a HUGE fan of Altarinano for MANY years and even was invested to the tune of tens of thousands of dollars with them at one point. All I did was lose money, and their stock has TANKED since then. 

I am results oriented. Going through the motions with no focus on results is a lost cause. Someday the guys with these products that look good on paper will realize just how stupid and short sighted they have been as they are passed up by people who actually understand the big picture, and not just their little slice of it.


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## JRP3 (Mar 7, 2008)

I too am a frustrated Altairnano enthusiast and stockholder, (though I only have a small position which I'm still holding.) The only recent good news I've heard is that they just delivered a new pack to the CurrentEliminator drag team and it's performing better than ever, and they expect to break more records this year.


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## donmurray (Jan 21, 2009)

Altair had/has a large container sized battery on the grid with AES (a power company). AES did some extreme cycle testing and had very good results. Purpose was handling short term power demands that normally requires a power co to constantly generate slightly more than they distribute. Also voltage smoothing, I think.

It looked like Altair has moved their target market to large scale applications where the cost of their high performace was justified. Another area where the high cost could be justified was in standby power backup. The US Navy was testing an Altairnano to see if a battery could eliminate the need to run two or more generators at the same time to get a fail safe system. High mileage fleet operation like buses are good candidates. Understand Altair batteries were physically large for the available energy (energy density) which might make them more difficult to package in a small EV. Power density was very good, and that would be good for maybe regen or phev systems.


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## kabalah70 (Jan 25, 2009)

*Altairnano*

I too owned and lost a lot of moeny with Altairnano. I hope they decide, with the restructuring, to follow A123Systems lead and actually manufacture the batteries. At least I will be able to buy them in a Phoenix Motorcars SUT in 2010, supposedly.


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## JRP3 (Mar 7, 2008)

Unfortunately Phoenix may be in trouble: http://www.autobloggreen.com/2009/01/10/ssangyong-goes-into-receivership-phoenix-doomed/
Maybe we should move this to the Phoenix thread or start an Altairnano thread.
http://www.diyelectriccar.com/forums/showthread.php/phoenix-motorcars-19944.html


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## dbc105 (Apr 30, 2008)

Just so you will know, Ford owns Volvo, or a large part of it. enough that when Volvo went to front wheel drive, they used a Mazda chassis and of course Ford owns 25% of Mazda. Need proof of that look at the little pickup trucks. The Mazda truck looks like a Range.

I would still be uneasy knowing there is not a solid link between the pedal and me stopping. Kind of like driving by wire, it's cool but I still like the steering wheel having a solid tie to the front wheels. Call it a Feeling of Security.

DC


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## donmurray (Jan 21, 2009)

dbc105 said:


> Just so you will know, Ford owns Volvo, or a large part of it. enough that when Volvo went to front wheel drive, they used a Mazda chassis and of course Ford owns 25% of Mazda. Need proof of that look at the little pickup trucks. The Mazda truck looks like a Range.
> 
> I would still be uneasy knowing there is not a solid link between the pedal and me stopping. Kind of like driving by wire, it's cool but I still like the steering wheel having a solid tie to the front wheels. Call it a Feeling of Security.
> 
> DC


You mean a solid link like rubber hoses full of, moisture absorbing, hydraulic fluid pumped by a vacuum diaphram fed with another rubber hose from the engine manifold.  Wheel motor braking would need some redundancy, split circuits, or one of those big triple hook type anchors you could eject out the back. Something like Wylie Coyote would use.

I've heard a comment that the unsprung weight concern with wheel motors could be held to tolerable limits by integrating the spindle and hub function into the motor. Sounds like a tricky, but feasible, design problem. One of the most interesting possibilities with these is the ability to control individual wheel traction under both braking and acceleration. A lot of potential there with vehicle control, in emergency conditions, far beyond what a driver could could do. Of course, the elimination of all drive shafts opens up space for batteries, allows more overall design flexibility, and probably reduces weight. Fewer parts? I just like the concept of removing drive shafts, U joints, transmissions, and using computer control at each wheel.


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## eUKenGB (Feb 21, 2019)

I think there needs to be an update on this.

To answer those last posts about regen, it is usual to apply regen when backing off the accelerator pedal, so most driving can be accomplished just by the use of that one single pedal (and fantastic that is once you get used to it). The brakes themselves would normally use hydraulic/mechanical systems, but could be a hybrid of mechanical/regen. However I think we can rest assured that there will always be the mechanical fail-safe.

I think hub motors have come a long way, but there are 2 major issues. First, they are unsprung weight and although the effect of that can be minimised with suspension design (or simply ignored as it's not that big a problem except for race vehicles), it does mean the motor needs to be more robust. Secondly, max. rotational speed will be between 1 and 2K rpm, so the motor has to be designed to produce torque at that low speed. However, that will never be as good as a faster spinning motor geared down can be made.

Having said that, those downsides can be dealt with sufficiently to make them a worthwhile consideration and so you can take advantage of their huge advantage - packaging. With the motors out in the wheels, the entire space left in the car due to removal of the ICE is then available for the batteries (and ancillary electrics). In some cars this can be a huge advantage. But…

As far as I can tell, the fact remains that all the manufacturers of any fabulous new motor designs, whether destined for hub or more regular inboard use, only want to sell to big manufacturers and not the DIY brigade like us. Not only does this prove they are in it only for the money and nothing to do with planetary preservation, but it is also very short sighted as there simply are not that many large scale manufacturers out there to be buying their product. I can't see the large auto manufacturers buying motors from an itty-bitty and unproven start-up. They will have the resource to design their own.

It doesn't help us, but I think these new electric motor manufacturers are heading down a blind alley. The car conversion market has the potential to be huge. It just needs some electric motor manufacturer to realise this and make their product available in small numbers and at sensible prices. Currently the lack of this is I think the biggest stumbling block to car conversion (and DVLA here in the UK, but that's another matter). Just how many Teslas need to be totalled otherwise to supply this demand.


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## brian_ (Feb 7, 2017)

For the hub-motor fans, I'll note that Lordstown Motors has shown their prototype pickup truck with hub motors from Elaphe. For the mechanical design enthusiasts, I'll note that this design does not use the potential packaging advantage, because the truck doesn't use the space between the front wheels and still has a beam axle between the rear wheels. For the cynics, I'll note that almost no prototype EVs from startup companies actually ever go into production anyway. The Lordstown Endurance is a reworking of the Workhorse hybrid truck, which in turn is an adaptation of a now-obsolete version of the full-size Chevrolet pickup.


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## remy_martian (Feb 4, 2019)

I thought the Workhorse was based on the F-150 and it was Via that was based on Chevy?

In any case, all of the mining trucks use hub motors, for the enthusiasts here that want to repurpose them for their ability to produce as much unsprung weight as possible.

The packaging argument goes away after you realize that most suspensions occupy space and that space, along with the space for attach points, can have a inboard AF motor with a planetary if you're really hurting for space. 

A real car also needs "crush space" and masses outside the safety cage help to reduce occupant deceleration rates in real crashes, so I think the reason we don't see hub motors out there is more than just unsprung weight.

I'd also argue that next to zero progress in hub motor design. Doesn't the YASA go back over a decade?


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## eUKenGB (Feb 21, 2019)

For a conversion I think the packaging advantage can be significant. I'm not talking about using space that didn't exist before (like where the suspension components are situated), just being able to make use of the entire ICE space for batteries. If that is being used for the motor and possibly some sort of gearbox, that leaves much less room for the batteries.

Case in point, I'm working on the conversion of a small mid-engined sports car. The engine is tightly squeezed into that space between the rear wheels. Once that is largely filled with the replacement electric motor, maybe attached to the original gearbox, there is not a lot left for batteries which therefore have to be distributed around the car as best you can. By using hub motors, that entire rear space can be used for probably all the batteries required for decent range.

Hub motors are no panacea I know and in many cases there are better alternatives. But in some cases their use can be extremely advantageous. It's finding a supplier that's the really hard part.


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## brian_ (Feb 7, 2017)

remy_martian said:


> I thought the Workhorse was based on the F-150 and it was Via that was based on Chevy?


Workhorse was created as a spin-off of GM, to take over building two series of GM commercial chassis. Lordstown Motors is related to Workhorse. The current Lordstown electric pickup prototype uses GM parts (including body panels). I just accepted a published statement that Lordstown adopted the Workhorse truck design, but they could be using any aspect of the technology. Ah yes, Via... yet another mythical electric pickup.



remy_martian said:


> In any case, all of the mining trucks use hub motors, for the enthusiasts here that want to repurpose them for their ability to produce as much unsprung weight as possible.


😂
But seriously, many (perhaps most) mining trucks have mechanical transmissions. The diesel-electric ones do normally have hub motors, though. At a more reasonable scale, some electric transit buses use AxTrax AVE electric portal axles from ZF and similar units from other manufacturers. They aren't exactly sports cars or luxury cruisers, and the motors don't actually fit within the wheels.



remy_martian said:


> The packaging argument goes away after you realize that most suspensions occupy space and that space, along with the space for attach points, can have a inboard AF motor with a planetary if you're really hurting for space.
> 
> A real car also needs "crush space" and masses outside the safety cage help to reduce occupant deceleration rates in real crashes, so I think the reason we don't see hub motors out there is more than just unsprung weight.
> 
> I'd also argue that next to zero progress in hub motor design. Doesn't the YASA go back over a decade?


I agree, generally. Were the YASA motors specifically intended for in-wheel applications? I don't recall seeing an example of one used that way, although it might make sense.


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## brian_ (Feb 7, 2017)

One of the recent examples used of hub motor use is Lordstown Motors, the doomed-to-fail startup intending to build pickup trucks. They were planning to use Elaphe motors. As expected, they have crashed and burned, so they are not and will not be an example of successful hub motor application.
Lordstown Motors falls apart


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## eUKenGB (Feb 21, 2019)

remy_martian said:


> …
> The packaging argument goes away after you realize that most suspensions occupy space and that space, along with the space for attach points, can have a inboard AF motor with a planetary if you're really hurting for space.


Don't follow your reasoning there. With a pair of hub motors tucked into the wheels, the space between is entirely available for batteries etc, but move the motor(s) inboard as you suggest and you've taken almost all of it away. Obviously suspension takes up some space, but everything needs suspension so it can be excluded from the comparison.



> A real car also needs "crush space" and masses outside the safety cage help to reduce occupant deceleration rates in real crashes, so I think the reason we don't see hub motors out there is more than just unsprung weight.


I don't get that either. I very much doubt the lack of commercial applications of in-wheel motors is down to what you suggest.



> I'd also argue that next to zero progress in hub motor design. Doesn't the YASA go back over a decade?


I don't think you can say there has been no progress. I think a lot of the technology is shared with wind turbines which have the same low speed goals as hub motors and for which I believe Yasa was originally targeting.

As I have said, in-wheel motors are not a universal solution. If I was to design an electric (sports) car from scratch, would I choose in-wheel motors? No. Some sort of personnel transportation device with a requirement for high manoeuvrability? Yes. Converting an existing ICE to electric? Maybe. Depends on the exact requirements and layout of the donor vehicle.

I have 2 projects in mind. For one I am considering in-wheel motors, while for the other I am not. Horses for courses.


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## JRP3 (Mar 7, 2008)

Just becuase a wheel motor might work for a scooter or something doesn't mean they make sense for most road going passenger vehicles. The inherent problems they had originally still remain. Space is less of an issue for battery packs now than weight and cost, and both continue to improve with time.


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## eUKenGB (Feb 21, 2019)

JRP3 said:


> Just becuase a wheel motor might work for a scooter or something doesn't mean they make sense for most road going passenger vehicles.


Agree…ish. Unsprung weight can be more of an issue with 2 wheel vehicles, but as you say, not so much for a simple utility scooter. For outright sports bikes, it is still of great importance. So just like for cars, in-wheel motors are a valid solution in some cases, but not all.



> …Space is less of an issue for battery packs now than weight and cost, and both continue to improve with time.


Disagree with regard to conversions. Space IS still very much the issue. This will diminish as battery tech improves, but there's a way to go before that really has any significant impact on trying to get decent range from a conversion. Right now, the space advantage can make the difference between a particular conversion having acceptable range or not. Again, it all depends on the specifics of a particular conversion.

Why the need to denigrate the use of in-wheel motors at every opportunity? Shouldn't we all rejoice in the fact that they can in some cases be used to advantage and make viable more conversions than might otherwise be practical? Aren't we all supposed to be on the same side here?


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## JRP3 (Mar 7, 2008)

Because many of us have seen a number of failed vehicles and failed companies promoting impractical wheel motors. I'd say it's better to discourage the use of wheel motors especially for DIY'ers because it's more likely to end up not working well. So yes we should denigrate impractical technologies at every opportunity so that they don't get misapplied. No conversion will get a meaningful amount of additional range from using hub motors as opposed to a compact transaxle setup. People should work on adapting used parts from existing production EV's, they'll have a much better outcome than trying to use wheel motors. There is no reason to think hub motors will somehow work better in DIY projects than they would in OEM products. There is a reason the most advanced OEM's such as Tesla don't use them.


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## brian_ (Feb 7, 2017)

eUKenGB said:


> Obviously suspension takes up some space, but everything needs suspension so it can be excluded from the comparison.


Yes, everything needs suspension, and that's exactly why it can't be excluded from vehicle design considerations.



eUKenGB said:


> With a pair of hub motors tucked into the wheels, the space between is entirely available for batteries etc, but move the motor(s) inboard as you suggest and you've taken almost all of it away.


With typical independent suspension the portion of the volume between the wheels which is remains for anything other than suspension is minimal compared to the volume of that length of the vehicle. Taking all of it for motors makes little difference to the total volume available for battery.

The Lordstown Endurance scheme used the stock front suspension and even structure of a previous-generation GM pickup, so it managed to have no usable space between the wheels for anything else. At the rear, they used a beam axle so there was no way to put anything else in that space, and they couldn't have a low cargo floor. The Endurance had the same battery in the same location as it would have had with inboard motors at both axles. If a vehicle is going to be designed for hub motors and get any advantage from them, it needs to be designed to work with them; just bolting motors on to hub carriers doesn't result in anything good.

Using Lordstown's own PR images, here's the Endurance from the front; the stupidity is also apparent from the rear.


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## brian_ (Feb 7, 2017)

JRP3 said:


> There is a reason the most advanced OEM's such as Tesla don't use them.


I would go further and say that there are reasons that no OEM uses them on any highway-capable vehicle.


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## eUKenGB (Feb 21, 2019)

Man you lot are too negative in your outlook and I'm afraid just plain wrong in much of what you claim. But this is getting boring. I've explained as best I can the pros and cons, but if you refuse to understand, hey, that's your problem. I know what I'm trying to do and why it makes sense. You obviously don't know either.

This could be an interesting discussion, but, er, isn't. So I will now leave you to your narrow mindedness. Just hope the OP gets his M700s sorted.


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## JRP3 (Mar 7, 2008)

Your emotional response and inability to accept the real shortcomings of the technology are the issue, not our "negativity", i.e. discussion of facts.


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## eUKenGB (Feb 21, 2019)

No-one has yet actually presented any valid shortcomings of the technology, apart from it making the wheels a bit heavier. No-one has presented anything remotely resembling an intelligent treatise on exactly what the problems will be. Just somewhat incoherent babbling about how you object to the whole idea. I am far from unable to accept valid technical criticism, just not getting it here.

What NO-ONE seems to have grasped is that I have made it clear that I am NOT trying to proclaim in-wheel motors a great solution in all circumstances, but only that they can be a better solution in some and in the same vein, no-one has asked what those circumstances actually are. Hence my conclusion that these are simply emotional objections without technical merit.

There is still the possibility that I will opt for a different solution, but I've not yet come across any technical reason to do so and I'm obviously not going to get that here. Maybe some other topics will provide more intelligent input.


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## JRP3 (Mar 7, 2008)

The shortcomings were discussed in this thread yet you chose to ignore them. The only babbling we've seen is from you denying reality.


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## brian_ (Feb 7, 2017)

brian_ said:


> If a vehicle is going to be designed for hub motors and get any advantage from them, it needs to be designed to work with them; just bolting motors on to hub carriers doesn't result in anything good.


For an illustration, there have been many specialty trucks built with a low cargo floor between the rear wheels, in some cases one that can be lowered to the ground. 








Since that's incompatible with conventional driven axles, these vehicles typically have front wheel drive, but that's not ideal for a vehicle which is rear-heavy when loaded. A good application of in-wheel motors might be to use them in the rear wheels of this sort of low-floor truck (probably forcing the battery to be under the cab), and Lordstown could have done that in the Endurance... but they didn't, so the in-wheel motors are pointless.


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## JRP3 (Mar 7, 2008)

Similar idea but using compact transaxle.


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## brian_ (Feb 7, 2017)

JRP3 said:


> Similar idea but using compact transaxle.


The Tesla Cybertruck has a conventional rear drive unit, which it can use because the box floor is high, unlike the low-floor example that I showed. Of course it could use in-wheel motors, too, but it won't.


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## JRP3 (Mar 7, 2008)

It was just an example of how you can achieve similar functionality with an adjustable suspension and telescoping tailgate ramp but not using wheel motors.

I'm not sure what you mean by "conventional rear drive unit".
Tesla Plaid drive unit likely going in the Cybertruck










Nissan LEAF drive unit











The difference is why I stated compact transaxle.


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## brian_ (Feb 7, 2017)

JRP3 said:


> It was just an example of how you can achieve similar functionality with an adjustable suspension and telescoping tailgate ramp but not using wheel motors.


But it's not similar - the floor height difference is huge.



JRP3 said:


> I'm not sure what you mean by "conventional rear drive unit".
> Tesla Plaid drive unit likely going in the Cybertruck
> 
> View attachment 122930
> ...


Yes, those are both conventional drive units. The Nissan unit is taller because the inverter is on top rather than on the side, and the PDM is on top of that rather than under the rear seat. The motors and transaxles are nearly identical, and comparable in size.

Oh, yes... all the stuff in Nissan's PDM (and in various places in the Tesla) is still needed with in-wheel motors.


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## M. Lewisham (May 14, 2021)

Are you North Americans ganging up on us Brits 😄
I'm a life scientist rather than an engineer ... .
so I suppose the issue with unsprung weight is that when a vehicle hits bumps at relatively high speed, there will be the aforementioned weight flying around in all directions, too disparate to dampen for a comfortable ride 🤔
Correct 🤔
Hmm 🧐 so who can advise me on the electric conversion of an old horsebox 🧐
i.e. 3.5 to 7.5 ton (tonne) box above the wheels 🧐
See my other thread 😃


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## JRP3 (Mar 7, 2008)

brian_ said:


> But it's not similar - the floor height difference is huge.
> 
> 
> Yes, those are both conventional drive units. The Nissan unit is taller because the inverter is on top rather than on the side, and the PDM is on top of that rather than under the rear seat. The motors and transaxles are nearly identical, and comparable in size.


I disagree with your characterizations and will explain why. The height difference is not huge, it's maybe 8 inches or so, and consider we are comparing one vehicle designed to be as low as possible with a truck designed for off road ground clearance running on 35 inch tires. Put lower road going tires on the Cybertruck, reduce the suspension angle and lower the mounting points for the transaxle and I think you could get within a few inches of the low rider truck. Further since your average truck has no need for the power levels provided by the Plaid drivetrain the motor sizes could be even further decreased, allowing an even lower bed.


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## Sagecrumpton23 (May 28, 2021)

BrianWillan said:


> Greetings All
> 
> I am new here. I found this site while doing research on a EV conversion.
> 
> ...


I was considering Using a hub motor on my EV conversion but decided against it because I was worried about a couple things first was the handling due to extra weight in the wheels and all the Wheels spending at the same speed I would sink would cause poor handling kind of like binding when you forget to shift out of four-wheel-drive also I don’t know how sealed the motors would be but with you living in Canada and me moving to the rust belt next year I was worried about the salt water getting into the motor bearings if you are looking to simplify your build I would consider 


BrianWillan said:


> Greetings All
> 
> I am new here. I found this site while doing research on a EV conversion.
> 
> ...


Sorry if this reply post twice I switched webpages and I don’t know if it posted before butI was considering doing some thing similar on an ev conversion of mine but decided against it for a couple of reasons first off which I think would be most concerning to you is road salt getting into the motor bearings Think about what your brake rotors look like after going through the snow and slush but that being an electric motor that may or may not be perfectly sealed Second is that unless the controller has some type of torque vectoring I would think with the two motors running at the same speed on a front wheel drive vehicle or a rear wheel drive for that matter you would experience some poor handling due to the added weight inside the hub and the motor spinning the same speed I would think that would cause binding like in a Vehicle with a welded differential or part time 4wd and last of all Longevity this is a really compact application so everything would have to be packed in really tight which in my experience means they will skimp on the copper which would produce extra heat not to mention virtually zero airflow inside a sealed hub motor so it would be passively cooled maybe with some fins on the outside to dissipate heat and the motor would have to spin pretty fast to get you up to highway speed being a 1:1 gearing I could be wrong because in hub motors have Ben used in hybrid hyper cars in the past but I don’t think diy hub motors are quite there yet your best bet is if do you have a manual transaxle in that car is to build a adapter plate To attach the drive motor to the transmission or if wait saving is really that important and you feel up to it you could remove the clutch and all but 1 gear set and weld it in place then essentially make it a single speed transmission good luck on your project and don’t forget to have fun


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## brian_ (Feb 7, 2017)

Sagecrumpton23 said:


> I was considering Using a hub motor on my EV conversion but decided against it because I was worried about a couple things ...
> ... all the Wheels spending at the same speed I would sink would cause poor handling kind of like binding when you forget to shift out of four-wheel-drive


That's actually a reason to use individual motors for each wheel, whether they are in the wheels or mounted to the frame. The individual motors do not turn at the same speed - they turn at the speed determined by the vehicle's motion and the motor controllers, as with an other EV motor. Each motor gets its own controller, and its own control of torque and speed. that independent torque control is ideal for handling.


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## brian_ (Feb 7, 2017)

Sagecrumpton23 said:


> ... the motor would have to spin pretty fast to get you up to highway speed being a 1:1 gearing...


It's actually the opposite. The wheels of a car turn very slowly by the standards of electric motors (or even engines), so normally there is a gearbox between the motor and the axle with a ratio which typically around 8:1 (so the motor turns eight times as fast as the wheels). A motor without reduction gearing (such as the classic direct-drive hub motor) only turns at the wheel speed, so it needs to be large and heavy to produce enough torque compared to a motor with the advantage of reduction gearing.

Example: Nissan Leaf
tire size (current year, base model): 205/55R16 - overall diameter 632 mm (24.9"), 519 revolutions/km or 836 rev/mile
wheel (axle) speed: 865 RPM at 100 km/h, or 836 RPM at 60 MPH
drive ratio: 8.193:1
motor speed: 7087 RPM at 100 km/h or 6849 RPM at 60 MPH
torque to wheels (at low speed): 8.193 * 320 Nm = 2622 Nm, or 8.193 * 236 lb-ft = 1934 lb-ft
(the same size of motor would only put 320 Nm or 236 lb-ft to the wheels without reduction gearing)


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