Motor overheating issues

I have been riding my board a lot recently between classes and noticed it was cogging randomly a few times. (it would randomly feel like it’s braking and make a loud sound) Then I was riding it pretty hard once and checked the motor with a heat gun and it read 300 degrees F! I even dripped water onto it and it steamed off. It has since stopped working completely. It just cogs and shakes when I push the throttle.

motor: OM 5065 200kv esc: Ollin vesc batteries: 10s LiFe my build log

Possible causes:

  1. It is hot right now where I live (110 degrees when I am riding)
  2. I tried @ackmaniac’s vesc firmware with watt control mode a few months ago and noticed it got kinda hot, so I immediately switched back to the regular firmware (maybe once the magnets start to demagnetize it just keeps getting hotter and worse)

Anyone else have issues like this, maybe I need a 63mm motor for the AZ heat?

Oh no…if it is so hot it boils water then you can pretty much guarantee the thing is shot. BLDC motors we use don’t like anything hotter than 180f. Because you are in such a hot area the ambient air does a lot less good of a job keeping the motor cool. A 63 size would likely solve the issue if it is just the motor that is undersized. If you’re over geared you will also have overheating issues caused by the immense amount of amps that are required to sustain the torque needed.

Sounds cooked dude :rage:

yeah 63mm will be cooler but so would going for a longer motor, plenty of 6374’s around for fair money atm :wink:

what’s your gear run out?

@cobber My gearing is 16 to 36. My actual top speed is 20 mph, so nothing crazy. I guess I will try a longer 63mm motor. Maybe on my next board I will go 12S so it won’t pull so many amps.

Anybody know of any good long 63mm motors that work well with the vesc and 10s LiFe?

Also I realized the new motor bolt spacing has to be 27 mm (or 38 mm measuring diagonally) to fit my current motor mount. Otherwise I will have to get/make a new mount :sweat_smile:

The SK3 6374 192kv is a good popular motor. It’s what I’ve got at 6S on my board and while I haven’t ridden it for very long yet, and not in any kind of heat, after about 15 minutes of hard acceleration and braking and some longish continuous runs at full speed it was only barely warm. Once I’ve got my enclosure done so the ESC stops trying to fall off the underside I’ll take it for a proper test run from full battery to none :stuck_out_tongue:

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yeah I’d try a 6374, or there are some 6085’s getting around too. Certainly the 6374 is the popular choice: Hobbyking Dymond Kaly also has some if you look him up on the boards I think

or a 6374 sensored Alien Psychotiller

or a 6384 at 955g it is single beast. I think weight equals reliability for motors… Alien

or the 6085 Ollin

you could also try searches on fleabay, alibaba or banggood…

anyway a few options to get you started


Your motor may be under warranty if you contact ollin.

I had a motor burnout like this due to a seized bearing.

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@Clonkex @Cobber Thanks for all the suggestions!

@chaka Have you ever heard of an OM5065 getting to 300 F like this? The motor still spins freely so I don’t think it’s a seized bearing. I may have just been way overworking it lol. (with the AZ heat + the weight of me plus my backpack)

You have really tall gearing for a single 50mm motor. You need two of these of you want to use something as tall as 16:32 tooth. We can replace it but it will not like your current setup.

If you are riding heavy with a pack you might want to think about going dual.

Ya that’s what I figured :sweat_smile: My setup doesn’t have room for another vesc or motor mount so will just try a larger motor

@chaka does your OM6085 have the same bolt spacing as the OM5065?

No, the spacing is larger. What type of motor mount are you rolling with? I also have some 15 tooth pulleys if you wanted to have another go with a 50mm motor with more gear reduction.

I have an aluminum mount I made for the spacing of your smaller motors. my mount

I don’t wanna to lose any speed so I think I’m ready for a bigger motor. I guess I will have get a different mount and sell this one. It worked well for me for a solid year

What exactly is the spacing of your larger motor?

I’m currently deciding between the alien 6374 and the Ollin 6085.

@chaka, instead of replacing my OM5065, could you discount me that price on the OM6085? That would be awesome if you could!

Then I just have to find another mount and I will be riding again :slight_smile:

Sure, as long as you don’t mind sending the the 50mm motor back. Let me know when you are ready and I will generate a coupon for you!

Yup I can send it back, just pm me the address to send it too. And I’m ready to buy!

Also what mounts will fit this? is the bolt spacing the same as most 63mm motors?

Ollin Board Company PO Box 3391 Truth or Consequences, NM 87901

Yes they are the common spacing for 63mm motors.

Even reached 300C, the motor still will not damage. check all wires and connectors to see if the tin got melted

I just bought Chaka’s larger motor and the Torque boards mount for it!

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Awesome. Please keep us posted on how performance compares to the 5065.

@chaka, I’m currently running an OM-5065 so it would be really interesting to get a “postmortem” of what went wrong with @ndwallick’s motor :slight_smile: