# Look at these specs! Maybe we are barking up the wrong tree...



## rfhendrix (Jan 24, 2011)

http://yuneeccouk.site.securepod.com/PowerMotor_Tech_spec.html

This is for aviation applications but who cares! What do you all think about this, especially the light weight and high power motors?


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## Ziggythewiz (May 16, 2010)

Impressive numbers...enough to be suspiscious...

I suppose everyone else who has tried making a 5:4 HP:LBS ratio motor has been silenced before they made it to market?

"Yuneec is a young, progressive, forward thinking company"

I usually read that as "inexperienced, buzzword-filled, imaginative"


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## Yabert (Feb 7, 2010)

Humm!!... Curiously interesting!!

Motor spec = 1.2 to 1.5 HP per lbs peak..... Good ratio!
And in a realistic voltage range (- 200v)

But the RPM seem low for that much power!! 180 lbs-ft for an 11 diameter motor with REALLY short lenght (8.25")?????

Anyway, I need two... what is the price?...


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## Anaerin (Feb 4, 2009)

4 of those (1 per wheel), each running through a 4:3 reduction gearbox (a planetary unit on the end, perhaps, if length is an issue) would give a total of 324HP and a top speed of roughly 96MPH (155 KPH). Not too bad, but I'm not seeing a torque figure, and seeing as these motors are meant to drive propellers (and so not having much in the way of drag) that could be quite the limiting factor.


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## rfhendrix (Jan 24, 2011)

Yabert said:


> Humm!!... Curiously interesting!!
> 
> Motor spec = 1.2 to 1.5 HP per lbs peak..... Good ratio!
> And in a realistic voltage range (- 200v)
> ...


I emailed him, I will let you know...


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## aeroscott (Jan 5, 2008)

Anaerin said:


> 4 of those (1 per wheel), each running through a 4:3 reduction gearbox (a planetary unit on the end, perhaps, if length is an issue) would give a total of 324HP and a top speed of roughly 96MPH (155 KPH). Not too bad, but I'm not seeing a torque figure, and seeing as these motors are meant to drive propellers (and so not having much in the way of drag) that could be quite the limiting factor.


Propellers are a never unloaded . air or water they work much harder then a auto .


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## Salty9 (Jul 13, 2009)

Aero motors don't cause much worry about cooling with the prop spinning in front of it. Cooling would be an issue in a ground vehicle. Here's another motor to consider.

http://www.goldenmotor.ca/shopping/start.php?browse=1&cat=37&=SID

Real good price but I'm wondering about longevity.


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## Anaerin (Feb 4, 2009)

aeroscott said:


> Propellers are a never unloaded . air or water they work much harder then a auto .


The torque required to turn a propeller in air is considerably less than the torque required to turn a wheel against the ground, especially at low RPMs.


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## tomofreno (Mar 3, 2009)

> Not too bad, but I'm not seeing a torque figure, and seeing as these motors are meant to drive propellers (and so not having much in the way of drag) that could be quite the limiting factor.


 The 60kW version says 2400 rpm, so the torque = 60,000/(2400*2pi/60) = 238 N-m, or 175 Lb-ft.


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## rfhendrix (Jan 24, 2011)

Is that good or bad?


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## Anaerin (Feb 4, 2009)

rfhendrix said:


> Is that good or bad?


Well, assuming that same 4:3 ratio gearbox you'd have 233 lb-ft, with one on each wheel making a total of 933 lb-ft of torque.

Given that a 2011 Mustang with it's V6 engine gets 280 lb-ft, one wheel is pretty much comparable. So that's very good indeed.


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## Woodsmith (Jun 5, 2008)

High power, light weight, short frame...


Sounds ideal for my trike.
Even the biggest one is less then 1/3 the weight of my 11" motor.


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## Yabert (Feb 7, 2010)

Anaerin said:


> Well, assuming that same 4:3 ratio gearbox you'd have 233 lb-ft, with one on each wheel making a total of 933 lb-ft of torque.
> 
> Given that a 2011 Mustang with it's V6 engine gets 280 lb-ft, one wheel is pretty much comparable. So that's very good indeed.


 
Don't forget.... the 280 lbs-ft of the Mustang motor need to be multiply by the first gear ratio and the rear diferrential ratio..... 280 x 10 (around) = 2800 lbs at the two rear wheels.


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## rfhendrix (Jan 24, 2011)

Just an update: They still haven't answered my email. Maybe they only speak Chinese.


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## Jimdear2 (Oct 12, 2008)

For what it is worth the copywrite on that page is 2008. I think we would have heard more about them in a two year time span.

There are othe sources for these type motors though. There are planes flying with electric motors. There are a couple of you tube videos on them.


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## rfhendrix (Jan 24, 2011)

I could call them I guess. Some companies do not answer emails. From what I understand a light plane is scheduled for production with these motors that will be used for flight training. I remember when I first learned to fly as a teenager it took most of my money to pay for a couple of hours each month. I can see how electric would cut down on that some but not much really.


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## MalcolmB (Jun 10, 2008)

I believe the company is genuine – if you do a youtube search for Yuneec there are several videos showing various motors on test in paragliders and light aircraft.

There's a company in Slovenia that produces similar motors. They look to have great potential, but getting hold of a suitable brushless controller appears difficult. They're supplied by another company that doesn't seem keen to sell on a one-off basis.
http://www.enstroj.si/


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## rfhendrix (Jan 24, 2011)

So things are looking up. Thanks for the link.


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## coulombKid (Jan 10, 2009)

rfhendrix said:


> Is that good or bad?


The required gear reduction also multiplies torque. In the apps we saw for concrete saws running at 400 hz the gear box consumed part of the weight savings but not all.


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## coulombKid (Jan 10, 2009)

rfhendrix said:


> Just an update: They still haven't answered my email. Maybe they only speak Chinese.


or they already took-up with the fat cats.


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## rfhendrix (Jan 24, 2011)

coulombKid said:


> The required gear reduction also multiplies torque. In the apps we saw for concrete saws running at 400 hz the gear box consumed part of the weight savings but not all.


2400 rpm is certainly in the ballpark for aviation purposes. I think that is direct drive on these units. Of course some aviation applications use a reduction gear but they still manage to keep the weight down.

The nice thing about these aviation oriented companies is that they have a constant priority in everything they do to make it lightweight as well as reliable. The weight gain however in my opinion is not so great that it will revolutionize the EV industry but who knows?


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## Salty9 (Jul 13, 2009)

Permanent magnet motors are very susceptible to heat. When used for aero purposes they have big cooling fans. This is from Ripperton thread in the Bike forum. 



david85 said:


> Hey Ripperton,
> 
> Do you mind if I ask what the motor case temperature was when you reached 140C?
> 
> ...


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## PhantomPholly (Aug 20, 2008)

Anaerin said:


> The torque required to turn a propeller in air is considerably less than the torque required to turn a wheel against the ground, especially at low RPMs.


Depends on the propeller, but certainly there is very little torque required to get started (very little zero rpm load).

Constant speed propellers can absorb 100% of a motor's hp at as little as 1400 rpm (prop speed). Of course, the actual motor rpm will vary if it is geared.


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