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Discussion Starter #1
Hi,
I'm a student from the technical university of Hamburg/Germany and together with some 50 other students I'm planning to participate in the 1012 formula student electric competition. Until August 2012 we want to finish our electric racing car. Currently we are in the concept phase and are having some troubles with finding suitable motors. According to the rules we may never draw more than 100kw from the batteries. We have decided to use two rear motors, so their peak power should be around 50kw. A good power/weight ratio and efficiency is very important and the price is not that important, since we have to get it paid by sponsors anyway… Could someone recommend us suitable motors for this purpose? I’d appreciate any tips
Lukas
 

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Hi,
I'm a student from the technical university of Hamburg/Germany and together with some 50 other students I'm planning to participate in the 1012 formula student electric competition. Until August 2012 we want to finish our electric racing car. Currently we are in the concept phase and are having some troubles with finding suitable motors. According to the rules we may never draw more than 100kw from the batteries. We have decided to use two rear motors, so their peak power should be around 50kw. A good power/weight ratio and efficiency is very important and the price is not that important, since we have to get it paid by sponsors anyway… Could someone recommend us suitable motors for this purpose? I’d appreciate any tips
Lukas

http://www.uqm.com/pdfs/HiTor%20spec%20sheet%203.30.11.pdf

edit: I have no financial or business interest with this company. Regards, major
 

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Discussion Starter #4
Hi, thanks for your answers.
I will try to contact HPEVS for more information on their motors.
The UQM Motors look really good, their disadvantage seems to be their high mass.
Here You can see some specs of the car which won last years competition. It weights only 200 kg without driver. So I don't think that we can afford to spend 82kg on two motors alone, considering that we will need about 6-8 kwh of battery capacity which will also weight about 70-80kg.
We already contacted AMK, the manufacturer of the Stuttgart-car’s motors, but they were not interested in any further involvement in formula student, since they already support a lot of teams.
According to Wikipedia, the Tesla’s motor weights only 32kg at a power of about 200kw. And this motor is only air-cooled, while we decided to use liquid-cooling. I think that for a racing car, we really need lighter, high rpm motor.
Any further ideas?
 

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Hi, thanks for your answers.
I will try to contact HPEVS for more information on their motors.
The UQM Motors look really good, their disadvantage seems to be their high mass.
Here You can see some specs of the car which won last years competition. It weights only 200 kg without driver. So I don't think that we can afford to spend 82kg on two motors alone, considering that we will need about 6-8 kwh of battery capacity which will also weight about 70-80kg.
We already contacted AMK, the manufacturer of the Stuttgart-car’s motors, but they were not interested in any further involvement in formula student, since they already support a lot of teams.
According to Wikipedia, the Tesla’s motor weights only 32kg at a power of about 200kw. And this motor is only air-cooled, while we decided to use liquid-cooling. I think that for a racing car, we really need lighter, high rpm motor.
Any further ideas?
The Tesla motor isn't 32kg, but 50kg http://acpropulsion.com/products-drivesystem.html. See if TM4 http://www.tm4.com/electric_powertrain.aspx can sponsor you. There are places that can make very high RPM motors, but the cost is very high for them.
 

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This isn't the approach you were planning but consider this route:

Kostov 9HV with a Soliton1 controller and a string or two of headway cylindrical 8AH batteries. Set the Soliton to limit your power to 100kw and try to have as wide a power band as possible using gearing to your advantage. The Kostov weighs in a 45kg, should handle peaks of 100kw, and should be less complicated than installing and controlling dual AC motors. You will also have the advantage of greater torque and much lower pricing.

Could you give us some detail on what the contest actually entails?
 

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Discussion Starter #10
Could you give us some detail on what the contest actually entails?
We want to participate in the formula student germany electric championships, which is a part of the worldwide series of formula student championships.
It is a design and racing competition for students. In Germany is an annual event since 2006, but only since 2010 there also is a competition for electric racecars. So far there has only been one of these competitions and in August 2012, when we are planning to participate will be the third season.
The goal is not only to win one race but to gain as many points as possible. You can get points for dynamic and static events. The dynamic events include for example a 22km endurance-race and 75m acceleration contest. The static events include the design documentation and business presentation. In 2010 only 8 of 15 teams had their cars ready for the endurance race and only 3 finished it! For this year there are already 30 teams registered and 2012 probably a lot more. At the same time there will still be the combustion championship with 90 teams.
While many participants of the electric championships took part in the combustion competition before, we are starting right away with an electric car.
Here are all the rules for the electronics part of the car.

MalcomB said:
No, I had not seen them before, but the specs look really great. My team mates also were really enthusiastic about this motor, and we will contact them next week. One motor weights only 11,9kg at 35kw cont. power. They do not yet build a controller of their own, but recommend one from a German company. And the controller also weights "only" 13kg, which is the lightest weight I have seen anywhere so far. But I still can't really believe it that this light motor has this power at only 3000rpm. probably it is because the diameter is high compared to the width (222mm*86mm)
This is definitely our preferred choice for now, thank you so much for this hint!
I'd also like to thank all you other helpful folks for your answers, I like this forum.
All the best
Lukas
 

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I'm glad the motor fits your needs. I'd also really like to hear any more information you learn about it. These motors look to have great potential – the difficult part seems to be finding a controller that can fully exploit that potential.

You might also find these interesting: http://yuneeccouk.site.securepod.com/PowerMotor_Tech_spec.html
They're intended for electric airplane use, so will require some serious cooling to achieve their rated output.

Please keep us updated with your build.

Malcolm
 

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Discussion Starter #12
Hello,
our project is on it's way and we have almost finished our concept.
The EMRAX motors will cost us 2700 € each and for the controllers we will probably use the BAMOCAR-D3, which the manufacturer UniTek would give us for the price of materials. But Yesterday we realised that the main missing part of our concept are the batteries and I opened a new thread for this topic. I would be very happy if someone could give us advice on the batteries. They are our main problem now.

Lukas
 

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depends

how many volts?

how many amps continuous? how many peak? how long is peak sustained? Is cell monitoring required? weight limit?

need a little more info in order to steer you
 

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Bear in mind the EMRAX motor is like a big axial flux outrunner, so you might need to work an enclosure around the motor(s) for safety. Let us know how you get on once you take ownership of them - I'm dying to know how they go!
 
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