Motor sound: Rpm interval where it seems the Turbo is kicking in!

Here is the problem: https://youtu.be/gGPGNwLu90U

The motor is performing as usual. But now I stepped up from 6s to 9s, the sound the motor makes when going to a certain Rpm interval scares me a bit :smiley:

Somoene has a fix? Is this normal?
Thanks!
P. S. Motor is one year old. Rode 2-3 times in wet conditions

What is your esc, and the motor timing setting if you have one?

Alien power system esc. With normal motor timing and fast acceleration curve

Try lowering the timing and see if the turbo kicks in sooner, if not, alter the accel curve. Does it happen when you’re riding?

I will try that tomorrow! Yes it happens to me while riding.
The motor vibrates heavily when you hear the noice

Already tried altering the acceleration curve with no effect

Not trying to hijack the thread, but I have a similar sound. Check it out https://youtu.be/i5MMdhEQquM1

Different RPM, and different tone, doesn’t seem to vibrate the deck like yours. Did you find a fix? Have you been riding the board normally since, and if so has it worsened at all? This is a new motor and the sound just came in this morning so I’m a little concerned. Would be interested in hearing how yours is doing…

Yes I know this. all maytech and freechobby manufactured motors make that vibration at resonant frequency. This motor is defective and will not last long. The small screeching you hear will soon get alot worse as vibration continue to shake the inside of your motor apart. Eventually you will have loose magnets and the motor will stop sinning freely. I have killed 5 motors with this defective design already. They break within a month. I informed maytech about it and i’m not sure if the fixed it.

I suspect the problem is the spacer below the circlip on the shaft is too thin. I confirmed this with @Kaly. The extra millimeter of space allows the shaft to move a little and thus the vibrations. You can remove the circlip and replace that spacer with a regular skate speed washer that is thicker that should stop the extra movement and the vibrations.

Thanks for the input, I will look in to it. Do you know of anyone who has replaced the spacer? Would love to see some photos to get better idea of what to do.

yes me and @Kaly both replaced spacers.

Thanks for the image. I still don’t understand what the function of the circlip and washer are though? (See the image I’ve attached below of my motor). Does the motor shaft get narrower next to the circlip or what? Is it back and forth movement (of the motor shaft) that this will help eliminate? Did the vibrations at the resonant frequency stop once you added the washer?

I’ve screwed everything together using high strength tread lock, so I don’t want to take it apart until I’m 100% sure on what I’m doing.

Many thanks for your help!

Also you said you were in contact with Maytech? What did they have to say? No indication towards compensation at all?

No the shaft does not get narrower.

Adding a thicker spacer will help eliminate the back and forth movement of the motor shaft and motor can attached to it.

Once the movement is eliminated the vibrations will not happen anymore. you shouldn’t hear that noise anymore.

I hadn’t had a chance to look into it until yesterday. I went back and forth a couple of times in the living room, just messing about, and the motor failed. Out of nowhere it just began clicking (as if the magnets were rubbing against the coils), here’s a quick video: https://www.youtube.com/watch?v=9jgq_bnqFD4 I’m so surprised by how quickly the motor went after the sound first appeared (never taken on to the road)

I took it apart today and it turns out that that is the issue… There are scratch marks on the magnets and they have come loose a tiny bit. I’ve just emailed Maytech so I’ll let you know when they reply. I’ve never contacted them before so I’m just hoping that they were cooperative…

Reglueing the magnets seems like a pain to do correctly, so I would much prefer a replacement if I can get one! :cold_sweat:

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I had the same problem with jlabs also before the motor fell apart.

@BoardSportsRN You are not playing with fire since they most likely won’t lock up while ur riding. But they will deff not last much longer. I haven’t had much luck with any motors other than sk3. Been running for 15months no problems.

@Baz_L Gl trying to get your replacement from maytech. They put me through hell. U should just dispute the PayPal charges. That might light a fire under thier asses.

I’ve made it clear to them that I’m coming from a very serious place on this, and I generally have luck when dealing with Chinese companies. I can’t dispute the case though as I bought through my agent rather than direct from Maytech so it complicates things a lot. They are not obliged to replace it, technically speaking. But I’ve put out a word warning to them so I’m at least hoping for a reply of some sort (which they didn’t give me this morning which isn’t very China-like)…

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Shoot me a PM with a video, I still don’t fully understand the problem (didn’t read every post in this topic). I will replace it if there was a manufacturing default that causes it to not function properly.

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Update on my motor situation: Maytech have replied! They’re going to take my motor back and fix it!! No questions asked, I just gotta pay postage. I hope they don’t mind that I opened it up to inspect it. I’ll keep you updated.

They offer that all the time. Cant believe your satisfied with that solution.

They put me through hell because I refused to pay return shipping for their defective products. I already paid shipping to me and their paypal fee. That was more than enough for me. They should pay their own shipping back. Not sure why we have to pay for shipping that costs more than cost of motors when they are the ones that fucked up by selling these defective motors to everyone.

In the end, after i threatened to dispute the charges with paypal they finally agreed to just send me new motors and paid for shipping to me. They didn’t make me send anything back even. seems like its more cost effective for everyone.

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