Brushless getting super hot in less then a minute?

[KidAgain]

I noticed a major problem yesterday, just slow driving on driveway about a minute and a half the brushless motor (4.5 Novak) , esc and esc cap (novak GTB) were hot I mean the motor wires got so hot that 2 de-soldered themselves at the connectors.

Motor spins freely not sure if the ESC cap is bad but what would the issue be on a Novak GTB to do this.

Set up that I run in all my cars:

[winner_evo]

I had a new Speed passion motor get really hot in less than a minute. Used a different motor and everything was fine so in my case it was a duff motor.

[KidAgain]

I had a new Speed passion motor get really hot in less than a minute. Used a different motor and everything was fine so in my case it was a duff motor.

Did the motor feel any different then the replacement did it spin freely or sound weird. Mine looks smells and feels like my new motors so I’m confused.

[winner_evo]

I couldn't feel anything amiss with the motor. Mine got hot like yours, just checking the diff, trims and esc settiings etc. I took it for a proper run and I had to stop after a couple of minutes as everything was getting hot. I then set the esc timing to zero and lowered the gearing as low as I could and it still got hot.

It was a 10.5T, so I swapped over to a Trackstar 10.5 with all the same settings and the temps were normal so I fitted a SpeedPassion 8.5T and temps were normal with that too.

The motor was new out the box, just faulty.

[RC10th]

If the motor feels like the brakes are on when unplugged from the esc the motor has a shorted wind, if not and you plug it into the esc and it feels like the brakes are on the esc is shorted. Not always 100% accurate on the esc side but it's a quick easy test to try.

Does the motor cog at all? Looks sensored so it shouldn't cog at all. Most sensored combos can run either sensored or sensorless these days so try removing the sensor cable and run it to see if any difference.

[KidAgain]

If the motor feels like the brakes are on when unplugged from the esc the motor has a shorted wind, if not and you plug it into the esc and it feels like the brakes are on the esc is shorted. Not always 100% accurate on the esc side but it's a quick easy test to try.

Does the motor cog at all? Looks sensored so it shouldn't cog at all. Most sensored combos can run either sensored or sensorless these days so try removing the sensor cable and run it to see if any difference.

No cogging seems to run great till it melts solder within a minute.....In novaks paperwork it says if the power trans cap goes bad esc and motor will get hot but how the heck would I test the CAP.

At what temp does solder melt? the only place it was melting solder is at the motor wire connectors all 3

[RC10th]

Could also be the gearing or power robbing belt drive.

Normally if the cap goes bad the end with the "K" will be puffed up or worst case you'll see a light brownish fiber like material in the general area.

Also don't use bullets with the cagees, use solid ones. Is the motor getting hot or the connectors. I have seen the bullet tube connectors melt in the battery case on quite a few occasions.

[KidAgain]

Could also be the gearing or power robbing belt drive.

Normally if the cap goes bad the end with the "K" will be puffed up or worst case you'll see a light brownish fiber like material in the general area.

Also don't use bullets with the cagees, use solid ones. Is the motor getting hot or the connectors. I have seen the bullet tube connectors melt in the battery case on quite a few occasions.

No belt drive its a direct drive set up gearing is 91/27 and I'm literally driving it under or just at a minute before motor gets hot along with the solder joints starting to melt, ive never had problems with the bullet connectors I run them on all cars sometimes 15-20 minutes but I will take your advise and get me some solid versions.

The bottom of the cap was puffed up a little I was able to compress it with my finger nail it felt soft like lead could that be it???

Just for shits and giggles im gonna plug everything back in on the stand turn her on and see if it gets hot just sitting there...

Thanks guys

[KidAgain]

Did another test run and all I did was 1/4 throttle about 3 wide circles on the driveway and the brushless wires and connectors were already getting hot to the touch. I replaced the trans cap since I had one and it made no difference.

Next move try another 4.5 see if it has same symptoms

[Coelacanth]

Is the motor getting hot or the connectors. I have seen the bullet tube connectors melt in the battery case on quite a few occasions.

Bullet connectors can handle a lot of current. If the connectors are getting hot, it doesn't necessarily mean the connectors are the fault.

I assume the car rolls freely with the pinion gear on the motor removed? This will show any friction in the drivetrain. If the motor spins freely, and the car rolls freely independent of the motor, then you can probably rule out drivetrain & motor friction/bad bearings/etc. and focus on the electronics/ESC.

You mentioned something about direct drive, though...does this car not have a gearbox? That could play a part in this overheating issue.

[jwscab]

Try a no load test. Run the car off the ground and see how fast temps get up. Then pull the pinion and repeat the test. If you think the caps were squishy, then they are probably shot and aren't helping anything.

Novak systems are hit and miss also.

[KidAgain]

Everything spins freely no binding nothing same with the motor, one thing I made sure is this thing has to have the least rolling resistance I can get for drag racing all bearings are ceramic the dd trans is smooth as butter to top it off this thing is fairly light for an RC10 based vehicle.

I mean the drive I did in the driveway was so easy just 30 seconds 3 circles I didnt even think if binding was an issue it would show the effects of heating in that short a time and distance I ran it....



Let me change motors and see where we end up, all the advise you guys have given has been great I have tried to look at all my options but starting to run out.

[KidAgain]

Try a no load test. Run the car off the ground and see how fast temps get up. Then pull the pinion and repeat the test. If you think the caps were squishy, then they are probably shot and aren't helping anything.

Novak systems are hit and miss also.

I will also do this tonight wouldnt hurt.....................

[jwscab]

Testing on the bench can pinpoint what is getting hot first.

[RC10th]

Can you hold the motor for 5 seconds when it's hot?

Yes bullet connectors can handle a lot of current, but in high power/draw systems I have seen the cage type bullets get hot enough to melt stuff.