Turnigy Rotomax 50cc Disassembly

[CoulombMotorsport]

The 5.3 kW 12S Turnigy Rotomax 50cc motor, bought from Hobbyking, forms the crux of our electric drivetrain on our e-Bike that we designed and built for the 2015 Hunter Valley EV Prize competition (hosted in Newcastle, New South Wales, Australia).
The first motor we used shorted after an accident while showcasing the bike at a local EV expo and I took it apart to re-wire it. Unfortunately I forgot to video the disassembly or insides of the motor until I was done so when I ordered another 50cc as a spare I took the following video to show how to pull it apart and the general construction and inside of the motor.

https://www.youtube.com/watch?v=vk6VqEISPUg

I'll soon be posting some photos and video of the overall drivetrain and the bike itself.

 

[Byte]

Nice video! Useful information

 

[CoulombMotorsport]

Thanks Byte,

This was the test setup I used with the original motor (the one that got blown up) before it was used in our Kepler-style drivetrain for a small single-seater EV:
https://www.youtube.com/watch?v=kZcIaazEti0

After bench testing it, I created this Kepler Drivetrain where the Dlux 200A ESC from Hobbyking burnt out very quickly. I now use a Castle Creations HVF160
https://www.youtube.com/watch?v=nFP_tIWBLe4

What speed/range does your e-bike have? Just out of curiosity

 

[Byte]

I heard very bad things about those Dlux ESC's. Castle Creation ESC's are decent.

My bike has a top speed of almost 60km/h. I don't know the range, I never drive far distances.

 

[CoulombMotorsport]

Yeah the Dlux ESC's are massively overrated. Continuous current without being in airstream was about 60 A and that was hot, only way they can claim 200A is in a massive airstream. The CC ESC's are pretty great, we've just gotten the Serial Link so we can instantly export the datalogging to our Arduino based control unit.

Here is a picture of our bike, https://www.facebook.com/CoulombMot...9445379783444/969442513117064/?type=3&theaterwhich tops out at 103 kph with the tallest gearing we've got and which achieved 32 kilometres in one hour with 360 wH at the 2015 Hunter Valley EV Endurance Cup which brought us 3rd place.

 

[MrDude_1]

What's the width and diameter of the stator?

 

[CoulombMotorsport]

Hi MrDude1,

Here are all of the measurements I was able to get regarding the stator.

Hope it helps

 

[CoulombMotorsport]

Here is a very short video of the bike the motor powers:

https://www.youtube.com/watch?v=T5LVKKVtKa0&feature=youtu.be

That's max acceleration, we're currently limited by the 9mm belt drive which slips but it was designed more for efficiency that outright performance and acceleration.

 

[Byte]

Nice! Did you achieve 103kph with the CC ESC? That's very fast for such a small motor!

 

[CoulombMotorsport]

Yeah we did. My brother and I formed our team to compete in endurance events in Western Australia and then in New South Wales (3200 km away on the other side of Australia) in 2009. Because we have to lower our weight, frontal area and CoEfficients of Drag and Rolling Resistance to achieve the required efficiency to win, we actually end up with some pretty fast vehicles when we give them a powerful enough motor. Our 3 wheeled car requires only 229 Watts to do 30 kph so if we were to put the Rotomax in it then we could achieve pretty high speeds but that's not really the point of our vehicles.