Heat issues with Hobbywing 2800KV motor.

[NeoPyro]

I have a Hobbywing Axe 540L R2 (2800KV) brushless system in my Element Enduro. I really like it, but the motor runs hotter than I would prefer. My plan was to originally gear down, but it's already geared down so low about the only thing I could do is go down a tooth on the pinion from an 18 tooth to a 17 tooth which got me thinking. Should I gear up instead? Maybe my problem isn't that it is over geared, but rather under geared?

[D440]

17 sounds too high, how many tooth on the spoor gear? I would go down to 12-14 on the pinion

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[NeoPyro]

The spur is 87 tooth.

[D440]

Should be fine then, maybe you were pushing the pinion too hard on to the spoor? There would be a bit of play between gears.... Also check that your axles run freely when not connected to the trans... Same thing with the trans, make sure there's no resistance/friction

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[AC49]

an 87 tooth spur seems WAY too large physically.
Are you sure it's not rubbing inside the transmission? or as the other poster suggested perhaps placing too much pressure on the pinion gear?

Stock is a 56 tooth spur I think and a 13 pinion. I dropped to an 11 pinion and have been very happy with it running the stock spur. my HW motor runs slightly warm to the touch even after hours of run time.

I'm just guessing you've got some extra friction somewhere in the driveline.

[durok]

The Element Enduro uses 48-pitch spur gears, and they offer 78t, 84t, and 87t on their site.

87t spur, 18t pinion is stock...

[AC49]

Originally Posted by durok

The Element Enduro uses 48-pitch spur gears, and they offer 78t, 84t, and 87t on their site.

87t spur, 18t pinion is stock...

HAHAHA oh geez. When I clicked on this thread I thought I was still in the SCX10II section! oh geez! I was so sure the OP was talking about an axial, but I re-read it and sure enough... right there Element. My bad.

[durok]

Originally Posted by AC49

HAHAHA oh geez. When I clicked on this thread I thought I was still in the SCX10II section! oh geez! I was so sure the OP was talking about an axial, but I re-read it and sure enough... right there Element. My bad.

No worries!

Unfortunately, I can't comment as to the OP's problem, as I have yet to drop my upgraded motor and ESC in my Enduro.

Still stock except for servo, and wheels and tires.

[NeoPyro]

Hey guys, I thought I'd give everyone a quick little update/PSA. I did the "Automatic Motor Pairing" as explained in the manual and to my surprise it did help to lower my motor temperatures significantly. It still runs on the hotter side of warm, but it isn't so hot that it is uncomfortable to touch for an extended period of time. I'm still going to order an assortment of pinion gears to try out, but yeah, if you're having heat issues like I was try giving the "Automatic Motor Pairing" a shot.

[durok]

Excellent news!

Good on ya for posting what worked in the end...

[ferp420]

im pretty sure your over geared for that motor higher kv motors dont like to go slow they build up alot of heat like that so a smaller piniin will be needed to make the motor run faster and because its not struggling at start up it will run cooler atleast thats what im thinking

[Jay-Em]

There is a simple way to determine if the pinion is too big, or too small.

- Motor hot, but ESC not —> pinion too big/spur too small.
- ESC hot, but motor not —> pinion too small/ spur too big.

Why?

When an ESC has to switch too quickly, because the motor runs too many rpm, the ESC becomes hot. ( the reason why f.i. LRP wárns specifically to NÓT run their high-Kv motors without a load, added tothat, it could shatter the rotormagnets) When a mótor has to work hard, i.e. when overgeared with a far too big pinion, it draws more Amps, which -in turn- heats up the windings.
Allof this within reasonable circumstances, of course. When the motor heats up too much, its impendance/resistance will increase, which -in turn- heats it up more, and will start to draw more amps, which will in the end álso heat-up the ESC ( depending on its Amp-rating, of course) and lead to increasing temps and in the end ‘The Holy Smoke’

Funny thing about electric motors is that they -theoretically- have no limit to the power they can deliver, as long as one can keep them cool. They just gobble more and more amps. Until the windings burn, the magnets fade, or the power source gets overwhelmed ( provided You’ll run the motor in liquid nitrogen or something, You’d be surprised hów much power can be channeled through a simple brushless. There’s more to that, but that means a too deep dive in Gauss, switching, rotation and resistance. There’s also a physical limit to the speed that windings can be powered and switched etc. )

In short : Heat dissipation is the problem, nót if a motor has enough power, or not. Goes for ESC’s too, btw.