Motor heating problem

[Big-eyes]

I have ordinary brush motor in my ECO 8. I use 10 cell batery pack. I just love high RPM, as it allows my ECO a certain stability. But my motor gets very hot after 2 flights. I have 14 teeth gear mounted on the motor axis.
Does anybody have experiences with 14 teeth gear on motor axis and overheating. I think overheating is a problem of not "squeezing" enough rotations out of my motor per second, and the extra power transforms into heat.
Should I use 13, 12 or even 11 tooth gear on motor axis.
What do you think ? Am I right ? Any comment will be helpfull.
And just one more thing - I will buy brushless emediatley after this motor breaks up, so do not advise me to buy brushless... I know, I know ...

Thanks in advance.

Big eyes

[Robert]

Big-Eyes,

I'm suprised you haven't cooked your motor yet. You should be using a 10 or 11tooth pinion with the sport motor and 10 cells. I'm using an 11 tooth, 10 cell 2000mah pack with a Kyosho Magnetic Mayhem Reverse with excellent results (for a brushed setup). I started with a 10 tooth pinion but bumped up head speed a little with an 11 tooth because the 470mm MS Composite (symetrical CF) blades needed the extra speed or I had to use too high of a pitch curve. I went to great extents to keep the motor cool as I cooked the original sport motor in short order with a 10 tooth pinion, 8 cells and stock blades. I added cooling holes in the top of the canopy, added a car type clip-on heat sink to the motor and used silicone heat transfer grease between the motor and heat sink. Also used the manufacturer provided heat sink on the speed control for additional heat rejection. All of this made an incredible difference in motor temperture after a flight. I can actual hold on the motor case after a 8 - 9 min acro flight. The next mod will be ball bearings in place of oilite bushings in the motor - less friction less heat. After I use up the two MMR motors, I have a brushless Kontronik Drive 301 system to install. I'm having too much fun at the moment to invest the time to optimize a brushless setup. Hell, I spent lots of time getting to where I am now - I want to fly!. EP helis are not less time consuming than nitro powered, only cleaner and quieter. I enjoy EP more because I can fly out of my back yard without bothering anyone and they are more environmentally acceptable.

[giheli]

I took my daughter to watch the slimers fly there birds this weekend. While there is no comparison in the availible power, I am thank ful I have an e-heli. We saw one bird chop into the ground after some idiot turned on a transmitter that conflicted. It was absolutley the most violent crash I have ever seen. Quite sad! The motor was locked in hover speed after the first impact and it proceeded to turn, chop, and hack its way to oblivion instantly transforming a beutiful JR Vigor into a twisted wreck. This just doesn't happen in the eheli world due to emergency cutttoff circuits thankfully. I just thought these comments were apropoh' -- another reason to go electric

--GI

[GEORGE S.]

I just got my eco today and I like what I see... will post as progress is made.

[Vince]

Hi Big Eyes,

I agree with Robert about the 10 tooths pinion, that's what I have on mine with the Ikarus performance motor and 10 cells.
A best advise (I did it on my 2 ECOS) is to remove the rotor from a small PC processor fan cooler and place it on the top of the motor (I will say on the axis). You just have to drill a 3 mm hole in the center of the rotor. You can also use the fan from a "babyliss hair brush"


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Vince
website : http://users.swing.be/vincent.filbiche