Motor rattling and screaming

I’m having some issues with one of my 6374 190kv dickyho motors. Unfortunately it makes a rattling sound, and when it goes above a certain speed it sounds like someone yelling. Both of these are relatively new. I’ve already taken the motor apart and cleaned it with compressed air but it didn’t fix the issue.

Here is the motor when being turned by hand https://youtu.be/samvhofmiXI

And here is the motor spinning up when powered. The “scream” sound happens when I get up to a certain speed and again when ramping down. It’s much louder when I’m actually riding it.

Here are pictures of inside the motor

Does anyone know what’s wrong with it? Am I safe to keep riding? Thanks

those winding are so messy :sweat_smile:

do any of the magnets wiggle?
any scuff marks on the magnets or stator?
spin the bearings with your finger. any roughness there?
is the shaft attached firmly to the rotor?

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I had the same problem with both of my maytec motors out of the box. I was never able to figure it out and it didnt effect performance at all so i kept riding. Now more than a year later it makes the same noise and pulls just as strong as day 1

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None of the magnets wiggle and I don’t see any scuff marks on the stator or magnets. The bearings on the top and bottom spin perfectly smooth and the shaft is firmly attached to the rotor.

However, 2 of the windings are a bit loose - could that effect anything?

maybe if the loose windings flap around when it’s spinning fast, but seems unlikely…
can you snap a pic up close?

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That sounds possible - here are some pics

my Maytech motors sound very similar, they run fine for me too. Just smash that throttle and enjoy the tunes!

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Yes, it can resonate and make noise (not the noise in the first video) and eventually cause a failure. You do not want the windings to be able to vibrate. Put epoxy – or MG Chemicals #4228 – on that so they can’t vibrate.

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Thanks! Will do!

@b264 Thanks for the help!! I coated the top of the motor with epoxy and the noise is completely gone. I really appreciate it

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That would have likely caused a failure later. Glad you got it fixed!

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