# Choosing a suited brushless motor.

#### Jan-Abraham Joubert

Joined Apr 3, 2016
6
I am an engineering student currently working on a project where I have to replace the starter and alternator of a self-launch glider engine with a brushless motor for better weight distribution and weight reduction. I have done my calculations, but I am concerned whether I would be able to find a suited motor that will fit the specifications.
The motor has to fit on the tapered crank shaft, on the old alternator fittings. Don"t know if this is possible?
The specification calculated are as follow:
Power = 700 Watt
Voltage = 12 Volt
Kv rating = 650-700

Will I be able to find a motor for these specific specification??

#### BR-549

Joined Sep 22, 2013
4,938
What does starter mean?

Do you have any photos of the contraption?

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Joined Jul 18, 2013
21,226
Might be easier to integrate a P.M. DC motor?
Max.

#### Jan-Abraham Joubert

Joined Apr 3, 2016
6
Starter= Ignition system, but that's not the problem, because if the motor produces enough power and a initial starting torque it will be able to crank the engine.
I do not have any at the moment but will post as soon as I get photos, My main problem is the mounting of the motor.
Thanks,

#### Jan-Abraham Joubert

Joined Apr 3, 2016
6
Might be easier to integrate a P.M. DC motor?
Max.
What information are specifically looking for? I am very unfamiliar with Electrical motors seeing a am a mechanical student. But I will do some research on the P.M DC motor.

Joined Jul 18, 2013
21,226
'Starter and Alternator' is rather vague, is the system similar to automotive? series motor starter? Alternator generator? Battery supplied system? Starting what?
Max.

#### BR-549

Joined Sep 22, 2013
4,938
So, you are trying to replace a starter motor?

#### Jan-Abraham Joubert

Joined Apr 3, 2016
6
So, you are trying to replace a starter motor?
It acts as a starter, but once the engine is running it switches over and charges the battery as a alternator does.

'Starter and Alternator' is rather vague, is the system similar to automotive? series motor starter? Alternator generator? Battery supplied system? Starting what?
Max.
It for a small aircraft Twin-cylinder in line two-stroke engine, where the motor has to crank the engine. Once the engine is started the switch is made where the motor then acts as a alternator/ battery supply system.

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#### BR-549

Joined Sep 22, 2013
4,938
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#### BR-549

Joined Sep 22, 2013
4,938
I didn't do any sizing or anything. They might not have what you need. I was trying to figure out what is was.

I am familiar with motor-generator SETS. (2) Not all in one.

But I like the idea. They should do that on cars.

#### Jan-Abraham Joubert

Joined Apr 3, 2016
6
I didn't do any sizing or anything. They might not have what you need. I was trying to figure out what is was.

I am familiar with motor-generator SETS. (2) Not all in one.

But I like the idea. They should do that on cars.
I am positive this concept will work, at the moment my only struggle is to fine the suited motor that will fit on the mountings with the correct specifications. But I will post my finding once a complete the project.

#### BR-549

Joined Sep 22, 2013
4,938
Oh, I'm sure it will work. But your problem is not finding a motor. You don't need a motor.

You need a starter generator. BIG difference.

You better have some money.

I could be wrong.........but my luck has always been expensive.