Evolve GTX Bamboo Motor Torque Loss. Any Clues?

ESK8 Electronics
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1

Hi there,

I was at the end of my sk8 and wanted to wear the battery down a bit before I put her back on the charger for the night. There is a small hill next to my house so I put her in GT mode and got close to full speed before arriving at the base of the hill. About halfway up the hill, the left motor made a weird sound. The best way I can describe the sound is it sounded a bit like the motor was skipping or something weird. I jumped off the board immediately and walked it the rest of the way.

Once I got to flat ground I picked up the rear end and tested to make sure both motors would spin. Both motors spun well but the one that made the noise spun quite a bit longer after letting go of the accelerator. Usually, both motors stop immediately after letting go of the accelerator. I put the board on the ground to do a short ride test and it was clear there was quite a bit of torque loss.

Any clues??? This was a brand new board on it’s maiden voyage. :frowning: pretty disappointed.

2

your belt is too loose

3

How low was the battery % or voltage at the time you jumped off? How much did it recover before you performed these tests?

My thought it that the battery is low and the torque loss if across both motors. Definitely check out what GrecoMan said too cause the uphill part sounds like belt skip.

4

Your motor slipped on its bolts and the belt got loose. You heard the bolts slipping.

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5

Loose belt most likely

6

Hi Guys,

Thanks for the quick response. I did check the belt and it seems to be fine. The sound came from the motor internally.

The torque loss was just in the one motor. When I rode it again on flat it would make those weird noses again. These noises sound like they are coming from inside the motor.

7

the voltage was getting down to about 30% or so but on the climb it dropped down to 4% or 5% or so.

8

Rocks inside the motor? Sometimes they move to a position that scraps when turning and right after go to a position that don’t scrap

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9

it sounded very similar to this https://www.youtube.com/watch?v=3osVwtxKbpE

I don’t think its rocks in the motor because it doesn’t make the sound with run the motor off the ground or all the time when riding. It only makes the noise when its struggling.

The motor in question was also much hotter than the other motor.

Again when I run the motor off the ground and just let the wheels spin when I let go of the accelerator the good motor stops immediately and the weird motor continues to spin for a bit.

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10

perhaps you overheated your windings, now they’re shorting internally because the enamel degraded?

11

Is the set screw within the gear, connecting to the motor shaft, tightly in place? I had a motor give off weird clicking noises right out of the box; turns out one of my set screws didn’t have any blue loctite & it got loose, causing a small wobble/clicking noise between the motor shaft and the gear.

12

Not a bad conclusion. I took the board back to the shop. I will be looking for a refund or an exchange. It was fresh out the box no reason it should have any issues yet. I could understand if I physically damaged it or if it was 500-1000km into its life.

At this point I don’t want to mess around with cracking open motor cases. After I ride this one for a bit I will begin a DIY project and that’s when I will spend more of my limited free time messing around with motors and such. I have to say up until that point I was thinking about how it was the best purchase ever! Had a blast scooting around the city.

Hopefully the retailer and the manufacture will be good about it and do the right thing.

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