Hot E-Maxx motors

[DLS II]

Hi, just got my new 3905 E-Maxx running. The motors are running hot.(180-190) Speed control (EVX2 w/fan) 15-20 above ambient. Batteries (Turnigy 2s2p LiFePo4, 4.5 amp/hr, 6.6 volts) also 15-20 above ambient.Geared 22/68. Wheels/tires virtually same size and weight as stock. The motors are Astroflight #615 cobalt brushed.(7 pole skewed arm,10T of 21guage wire .069 ohm, oversize 7/16" communtator w/silver graphite brushes, machined aluminum endpieces and steel can w/10 cobalt magnets,BB's,KV 1488.) The truck weighs 10 lbs 5oz. Any ideas? Motors are about the size of a 550 brushed and weigh 7.5 oz. Thanks, Don

[suicideneil]

Brushed motors > suck balls.

Lovely as the description on the cobolt motors is, I doubt they are anything all that amazing or designed to be long lasting without much maintainance. Your gearing is wayy top high though- you should be using nothing higher than stock (18/68) with the evx2 as it wont stand upto much abuse as such- same deal too with the stock titans, so I;d say your motors are running hot because they are overgeared, regardless of the slightly lower speeds that the Life packs offer ( 13.2v nominal, 14.8v freshly charged ).

I'd say gear back down and see how things respond- should hopefully run cooler provided no damage has been done to the motors with the high temps..

[DLS II]

OK, looks like gearing down is the way to go. These particular motors were bought a while ago-not cheap-$135 each. At the time they were popular(and King of the hill) brushless were pretty much unavailable. In their FAI form they held a # of records for RC airplanes and were used for drag racing and pulling quite successfully. I had them on hand when I bought my E-Maxx a month ago and decided to use them. Don

[nitrostarter]

Originally Posted by DLS II

OK, looks like gearing down is the way to go. These particular motors were bought a while ago-not cheap-$135 each. At the time they were popular(and King of the hill) brushless were pretty much unavailable. In their FAI form they held a # of records for RC airplanes and were used for drag racing and pulling quite successfully. I had them on hand when I bought my E-Maxx a month ago and decided to use them. Don

Wow,

$135 each motor? Hmm. How long ago are we talking?

[DLS II]

I bought these probably 4 yrs. ago. They are available @ New Creations-RC on sale $110. These are some of the best compitition brushed motors. They will run @ 80% efficiency. I know-they aren't brushless! Before brushless these were the thing to have. Don