Aaron Michelle's Homepage

Western Washington University EET

Brushless Outrunner Scooter

 

 

Goal

A real-world test of large model-aircraft brushless motors and how they perform in personal vehicle applications.

Process

The first step was to pick out all of the components and find a suitable motor for my application. I would need a donor scooter and misc. electrical components.

The donor scooter that I picked up on craigslist.com.
cl scooter


The stock scooter is a rad2go.
Motor: 180W
Batteries: 24V, 12ah.
Top speed: 12 mph.
Gearing: 13T motor 72T wheel 8" tire.


The brushless motor just arrived in the mail.
This motor is rated at 3150W (4.22hp) @ 36 V.
brushless motor


Here is the 180W stock motor next to the 3150W brushless motor.
motor compare


I had to cut and weld a steel plate for the new motor to mount to.
mount cut


The process of building the motor mount/housing from the old motor and improvising with various tools
motor mount 1motor mount 2 motor mount 3motor mount 4 motor mount 5motor mount 6 motor mount 7motor mount 8 motor mount 9motor mount 10 motor mount 11

The motor mounted!
motor mounted on scooter motor mounted on scooter 2

The throttle (servo tester with extended wires to the potentiometer).
throttle

The led headlight.
headlight headlight 2

The headlight shining under my workbench.
headlight shining

Results

The finished scooter internals.
finished scooter

Performance

Motor: 3150W (Maximum Rated)
Batteries: 24V, 12ah.
Top speed: 24 mph.
Gearing: 13T motor 72T wheel 8" tire.

I am running the motor at 24V with a 120amp esc (electronic speed controller). The motor is rated 230Kv (230 rpm per volt). This gives a peak rpm of 5520 @ 24V. The torque is very impressive. It is a must to start from a roll because the shaft will spin in the cog which is press-fitted onto the shaft. Rolling to top speed takes about 4 seconds. The range is around 4-5 miles (pretty low but the batteries are only rated for 12ah and thus the current draw from the motor brings them down fairly quickly) you can cover that distance in a very short time though. Since the motor is so powerful and is only running @ 24V it would be perfect for an electric bike application even with the extra weight this motor could handle a lot more than the little scooter it is currently in. Some of the extra weight could come from larger batteries which would give even more power because of the current they would be able to supply.
So the end result is very promising, these motors are indeed very powerful and perform well in personal vehicle applications.