# Wheel motors



## Bowser330 (Jun 15, 2008)

not speaking for everyone around here, but generaly speaking, if you hang around here enough, most people have built DIY EVs with dc motors (forklift) and lead acid batteries...

To obtain serious interest from the members here and other future DIY'ers your wheel motor design/kit would have to be #1 available and #2 proven (with data)

and lets not forget #3 cost effective...

a 9" dc motor with 144V controller at 500A surge can give 50hp and 110ftlbs torque... motor costs 1500 and controller (curtis) costs 1500, total 3000$...

So if the wheel motor pair can provide the same (or more) power with comparable cost, I dont see why it wouldnt be embraced...


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## major (Apr 4, 2008)

arftist said:


> What is the general consensus on wheel motors around here? Not just an idle question, I have some ideas.


Hi arftist,

Don't know of any consensus. My opinion is that the wheel motor is a product everybody wants and nobody has. Been that way for 100 years. Maybe there is a good reason. Not an easy application.

Regards,

major


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## arftist (Mar 20, 2008)

So far it looks like Mitsubishi and BMW have wheel motors in the pipeline. To me, the benifits would include; ease of regenerative braking, reduced number of driveline components with a corosponding reduction in weight, and more flexibility of vehicle layout. The difficulty would seem to be the lack of variable gear ratios, but I think there are solutions to this.


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## david85 (Nov 12, 2007)

Wheel motors are a high end product. As such anyone that has them are usually big companies with big budgets and big prices to match. The only reason we even have access to forklift motors is they are often discarded as "junk". Its only after years of conversions that there is finally a market catering to us when it comes to forklift or other low tech electric motors. Don't count on that happening with high power wheel motors any time soon.

Technically, its a great idea though.


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## Stiive (Nov 22, 2008)

Look up the Eliica
http://en.wikipedia.org/wiki/Eliica

It has 8 wheels each driven by its independant motor. The car goes about 400kmph and is very quick off the line as you might imagine. Was developed by a uni in tokyo japan.

BTW - i wouldnt consider mounting a forklift or any sort of DC motor into the wheel, they just dont rev enough to get any decent top speed, unless you want to incorporate gearing in there too which just complicates things. This design would pretty much have to be AC.


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## slurryguy (Dec 16, 2008)

Stiive said:


> Look up the Eliica
> http://en.wikipedia.org/wiki/Eliica


I'm certainly no expert on anything. I'm just learning, but anyone interested in the Eliica's wheel motors may be interested in the following documentary video about it on YouTube.

This is the first video in the series. Fast forward to the 7:45 mark to view the inner workings of their wheel motors. They start with the special dense winding of the stator:
http://www.youtube.com/watch?v=J95Lh3NnL4A


2nd video of the series continues the discussion of their wheel motors where the first video left off. It discusses the NeoFe permanent magnet armature:
http://www.youtube.com/watch?v=ZISVJNJ6W2o


These motors are anything but trivial. They're very beefy. They appear to compete in physical size to some forklift motors. Judging that it takes 2 workers to carry them and install them in the car, the weight my not be too far different either. Performance is probably significantly better than a forklift motor, but I don't have any real data to back up that wild guess on my part. What do you expect? I'm just a schmuck trying to figure all this out? 

It's all very interesting for concept cars and futurists, but I really don't see it being DIY friendly for a long time. Still, it's a fun view on YouTube even though I know full well I'll probably never get to hook one up in my lifetime. That's just my very very humble lightly educated opinion. Personally, I'm just reading along over everyone's shoulder right now, but I thought I might share this tidbit with everyone since I knew it was out there.


(For those interested in the rest of YouTube series of that Eliica documentary, here are the rest for easy clicking. There are more mentions of the wheel motors elsewhere in the series. I recall somewhere in there they put them on some kind of dyno, but I don't remember which video it's in. Somebody will probably view the whole documentary and post about where all the motor video segements are.)
Video 3 of 5: http://www.youtube.com/watch?v=t8t2c9WErTc
Video 4 of 5: http://www.youtube.com/watch?v=Lw7nMLy81Vs
Video 5 of 5: http://www.youtube.com/watch?v=ILbsaaAqELg

Happy Viewing.


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## Stiive (Nov 22, 2008)

yeh soz i should have posted all those videos, i have seen them ages ago. Forgot to mention them. 
Very long but has some interesting parts in it


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## coulombKid (Jan 10, 2009)

I read a while ago the Volvo/Ford had developed wheel motors. I've designed them but never built one for testing. Power density and un-sprung weight are the two biggest hurdles. Using rare-earth magnets on the rotor and two mats of stator coils (3-phase) seems promising. A BIG problem with 4 pancake motors is you need 4 AC drives when going around corners. A good motor would resemble the alternator on otherpower.com turned inside out. Right now you would spend $1000 just on rare earths for a all-wheel drive EV.
In general the ideal motor will be an axial-flux permanent magnet AC motor with an optimized drive. The drive cost is what is holding me back. Mechanical construction of the motor is just no big whoop. When one gets built for the ultra-rich stability and traction control will be superb.
Two big advantages, if it can be done,: 1) you don't need brakes. 2) you don't need a transmission. Direct drive wheel motors.
Where your disc brake is today may be where the wheel motor is in ten years.


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## john818 (Aug 1, 2008)

coulombKid said:


> Power density and un-sprung weight are the two biggest hurdles.


Unsprung weight is the first thing that pops into my mind when I think of wheel motors. You were pretty vague about your application, but I'm a sports car guy, and weight is my enemy, especially unsprung weight. In general, higher unsprung weight means worse handling _and_ a rougher ride. I'd love to see someone make them work though!


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## coulombKid (Jan 10, 2009)

john818 said:


> Unsprung weight is the first thing that pops into my mind when I think of wheel motors. You were pretty vague about your application, but I'm a sports car guy, and weight is my enemy, especially unsprung weight. In general, higher unsprung weight means worse handling _and_ a rougher ride. I'd love to see someone make them work though!


 The easiest prototype for me is a bicycle with the rare earth magnets in carriers between every other spoke. The 27-or-so air core coil pairs go in two pancake stators on either side of the rear wheel. At 45 MPH my drive would have to be pumping out PWM chopped DC to get a sine wave current through the motor at 95 Hz. I'd like to dyno test the motor driving dual 30 # flywheels for a test load. True Vector drive computing power is a bit much for a bicycle so I'd like to try tunning the cells of look-up and look-down tables for a torque control set-up with enough discrete steps of speed to allow safe operation. I have two microprocessors that can talk to each other. One can handle the PWM look-ups like a poor man's DSP while the other handles supervisory I/O and a second set of look-ups and look-downs. I don't do ICE hot rods anymore so this project can keep me busy for a long long time. (and justifing way cool tools, computers, scopes, frequency generators, spectrum stuff).....you get the picture. I can use my DC welder during bench dyno work. I have to switch to a composite rim to cut the short circuit and prevent melting the spokes


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## goo_nadd (Apr 30, 2008)

Has anyone purchased a Flightlink wheel motor?

Do they exist ? The 30/60 model.

Any idea of the cost?
________
WEED BUBBLERS


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## goo_nadd (Apr 30, 2008)

I just saw a footnote on Flightlink page. Looks like they went bankrupt Nov. 08


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.
________
Zx14 vs hayabusa


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## david85 (Nov 12, 2007)

goo_nadd said:


> I just saw a footnote on Flightlink page. Looks like they went bankrupt Nov. 08
> 
> 
> 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.


I was not aware of that. Thanks for the info.


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## unclematt (May 11, 2008)

john818 said:


> Unsprung weight is the first thing that pops into my mind when I think of wheel motors. You were pretty vague about your application, but I'm a sports car guy, and weight is my enemy, especially unsprung weight. In general, higher unsprung weight means worse handling _and_ a rougher ride. I'd love to see someone make them work though!


For most wheel motor designs, unsprung weight is not an issue after you remove much of the brake and driveline compenents. 

This has all been covered in detail on the open source hub motor thread. Make sure you search the forums before starting duplicate threads.


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## goo_nadd (Apr 30, 2008)

Where can I purchase wheel motors? No response from Flightlink.
________
Vaporizer Affiliate


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## Bowser330 (Jun 15, 2008)

http://www.justgottascoot.com/vectrix.htm

I am not sure, but its worth a call to see if you could purchase a "replacement motor" for "your" vectrix scooter...

they are 21Kw motors and can propel 500lbs 0-60 in 6.8 sec...

Thefore if you had 4 of them...84kw...they should propel about 2000lbs 0-60 in about 6.8sec...

Get a lightweight donor car with some lithium packs and you might be able to keep it down to 2000lbs...


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## david85 (Nov 12, 2007)

Thats not like any electric scooter I've ever seen before! This one is rather nice compared to the ones they are selling in town here.

Also an impressive wheel motor on it. Generally, they are only 12kw or less. Hmm......


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## judebert (Apr 16, 2008)

Yes, but where are you going to find the batteries and controller(s) to produce 84kW for 7 seconds? It can be done, but it ain't gonna be cheap!


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## Bowser330 (Jun 15, 2008)

That sort of depends on if you could buy the spare parts in the first place from Vectrix or a distributer...

The Vx-1 costs about 10K$US...so how much of that 10K$ retail cost is the cost of the controller and motor...50%?...so 5K$...I wonder what they cost from China...

4 of them would be expensive (to buy brand new) but would be a true performer...and you could make a skateboard concept design like GM has..haha...different car bodies/frames attach to a common driveline contained chassis...


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