Electric Kart First Wheels-up Test- Brushless Etek

From http://acuteaero.com - first wheels up test of the "built in a day" electric kart, brushless etek motor and sevcon millipak controller- Either the controller or the hall sensors are having issues at certain speeds and causing the commutation stutters visible (and audible!) in this video.

Category:

Autos & Vehicles

Tags:

• kart
• electric
• brushless
• etek
• mars

[CalabreseMPC]

you have no idea do you.

[ledledledled]

@CalabreseMPC Your last comment (the one you deleted) said you thought there was something out of balance. Your comment on the other video said the motor is "fucked" You really have no idea. Nothing is off balance enough to cause the problems seen here particularly at low speeds. The motor is fine. The motor controller was malfunctioning and has since failed entirely. It was purchased used and was of unknown condition from the start. Thanks for your constructive comments.

[CalabreseMPC]

@ledledledled I'm sorry to seem blunt, but if your motor were balanced you would have another support at the end of the shaft after the chain drive. does it happen under hard acceleration? The problem has also probably seemed to have faded, and you might have had to tighten the chain?

[ledledledled]

@CalabreseMPC The motor shaft is short enough that it doesn't need additional support on the other side of the chain drive. Most electric motor chain drive systems are constructed this way. The actual problem manifesting with the stuttering and jerking drive is the motor controller malfunctioning- it's a brushless motor so it's electronically commutated- the motor controller is responsible for energizing the phases of the motor in sequence. It's messing up the sequence, causing that jerking.

[CalabreseMPC]

@ledledledled ahh yes! you wired ABC,123 the wrong way.

I just worry on the jerking downward on acceleration, even if it is minimal it is something to put into anther concept.

I have been tossing up whether to do this, the motor I am after is 17kw, but it costs too much for me to do now. what's your top speed, and does it spin from mid rev-range when you flatten the throttle?

[ledledledled]

@CalabreseMPC Haha- maybe I'm less of a moron than you seem to think-- everything IS wired correctly. The problem was inconsistent- not constant like what you would see from a wiring error. The controller was faulty.

On this first test it was geared for a very low top speed (15 mph maybe) and accelerated quickly but without wheelspin. That is, with the controller malfunction and at 36v. I was expecting better performance at 48 but didn't have a chance to test that before the controller failed.

[MrScooterFaster]

Damn, my comment went over by 2,338 digits!

I'll sum it up...Increasing the current during acceleration was a possible cure for the problem. I realize you determined the controller was at fault, but did you try reprogramming it? Increasing the ramp up rate might have solved the problem.

I found this was the solution to acceleration chatter on the Panterra brushless hub motor scooters I sold and repaired. Am I a moron for increasing amps until they caught FIRE?

It was FUN!

ScooterFaster

[116thcrazy]

I think that is cogging from the motor trying to pull more amps than the battery can supply. Try using some zippy lipos

[garbizwal]

What controler is that?

[CalabreseMPC]

@ledledledled Yeah i was kinda confused, it shouldn't be 3 phase anyway.

I'm very interested in the MX-5 conversion, is there any chance you could shoot me a msg with parts and prices?