What is this sound and how do i fix it?

I tried balancing the can, i made it almost vibration-free but whatever i try at that rpm it starts resonating like crazy. I had this same problem with “battle hardened” flipshit motors and these freerchobby ones come from the same factory.

Am I the only one that cannot play the video?

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It’s 48mb, if you got slow internet or the server for this site is bogged down it will take forever to load. Best bet is downloading, watching it and deleting it after

Edit: yeah server is crying in a corner right now. 400mb/s internet but can barely load pictures here

I think the motors hit a resonant vibration frequency that affects other mechanical parts, like the motor mounts and that causes the big spike in vibration amplitude and noise, as they start to vibrate in resonance with the motors.

If you touch the motor mounts can you feel a clear amplitude change in them when the sound gets worse?

I can do this with the motor hanging on the wires. One of my flipshit motors does the same thing, these freerchobby are extra shit and do it both.

And yes, they definetly have some extra vibration to them nearing that rpm, while they consume more too. They need almost 180W to pass that rpm and normal to 120W at full speed

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My pc says unsupported format, i wanna hear the noise pretty sure I have 2 motors with the same issue from description

Before ordering them I couldn’t find much info about it, after clicking pay all I read is bad reviews :cry: :sweat_smile:

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Valid 24h

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I would then guess that they start to resonate with the bearings, as there is always a tiny amount of slop in them, bouncing around more as the vibrations hit just right.

I guess a little looser/tighter shimming of the bearings could help or change the frequency at which this happens.

Otherwise I don’t really have an idea what else it could be, as there shouldn’t be anything vibrating/rattling on the stator or rotor, so all I can suspect are the bearings.

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They are new, that’s why. Bad reviews come in and they make a new company, bad reviews come again and they make a new company…
For what they are, they deliver. I get 110A through each of them, but skimping on things like properly balancing the cans really shows.
@SimosMCmuffin i could not get them open with anything, they slide about 5mm and lock up, and now there is a geardrive pinion loctited on so double no chance. Already trying to reach aps to get some motors from them now and fresh motor pinions from moon

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When you remove the circlip, you will see 2 really thin washers that you need to take off, they are exactly the diameter of the shaft so you will need to mess with that a bit, then the can pulls off easily, they are so small that I didn’t see them at first and pulled like an animal for a few times until my brain turned on haha


Yep, cleared to the bearing. One had 3 the other had 4 shims, neither would move past roughly where the retaining ring for the magnets meets the stator

Really weird, maybe some wd40 mixed with a bit of heat?

Shit motors are the biggest issue of this hobby imo, we got all other components super solid…
If I give up on college I will probably try to produce indistructable cans haha


I’m in no position to retry opening them now. Best guess is that the circlip you can barely see in the second pic is installed after the rotor comes on and glued in place, thus permanently locking it in place. I even tried hammering the shaft, it wouldn’t move a milimeter after that point.

There are good motors but they range from £250 to £400/piece and for a dual it’s already up to £800. There is no other component besides the battery that costs that much on an average board

If mine get stuck during pullout, I usually give a little extra taps with a plastic mallet to encourage the shaft to move.

I had to save it then opened it with VLC…

I’ve got the same issue with two of their older 6374’s. Just started making noise yesterday. Thinking about buying an arbor press as I have numerous motors laying around that need repaired, and it’s something I’d like to learn. Does anyone have any links to teardown videos of FS’s “battle hardened” motors?

I need to order replacement motors, and I really have no idea who to order from. Thus far I’ve tried Maytech and FS, and they have both failed too soon. Now what?

How hard is it to disassemble and rebuild (bearings/shaft) the Turnigy SK3 motors?

Does anyone on the forum offer motor rebuilding/upgrading services?