Corona motor gets REAL hot, is this setup right? - RC Groups
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Apr 25, 2004, 09:05 PM
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sizam's Avatar

Corona motor gets REAL hot, is this setup right?

I'm running a Krypton 14 turn brushed motor with a CC 35A ESC in a fully stock Corona with a 8 Cell 3300GP pack and a 9-tooth pinion, all up it weight is 2lb 13oz. The motor gets REAL hot, I measured it with a digital therm. (surface probe type, not laser) and it read 99C (so probably a couple C more). That was yesterday, today I was running it and it felt even hotter, the pack gets hot but I can hold it, and I get about 10min of hovering at around half throttle. Should I change to a smaller pinion?
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Apr 26, 2004, 12:45 AM
A-4 nut!!
skyhawk's Avatar
Actually - that's not too bad. Time the motor and put a heatsink on it. I also cut some cooling slots in the canopy. Runs very cool now.
Apr 26, 2004, 01:17 AM
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KnimRod's Avatar
I think 8 cells might be a bit much for that motor and your having to run it throttled way back which isn't very efficient. I ran that motor for awhile in my Corona and it worked great on 7 cells.

Apr 26, 2004, 01:56 AM
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Mheeli's Avatar
I used to hover my corona at half throttle as well, every thing was hot. I added more weight (add another batt pack) now I hover about 70-80% , the ESC got a lot cooler. I have a 5V fan blowing the motor so I don't know if 70-80% throttle helps the motor, I'll bet it does.

Ideally I should get a use a lower tooth pinion, but could not find one.
Apr 26, 2004, 12:39 PM
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sizam's Avatar
5v Fan huh, how'd you do that just plug it into one of the Rx channels?
Apr 26, 2004, 08:04 PM
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Mheeli's Avatar
I have a Y connector comming out directly from the Batt for the fan. 11-12V does not seem to hurt the fan and I get a lot stronger blow.
Apr 26, 2004, 09:36 PM
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thazy2's Avatar
void the heatsink........

go for the fan. Works much better at cooling. 5v is more effecient and lighter plus rev faster when 9.6 is applied, more than 1.8cfm thats for sure. And its much smaller which makes it easier to mount. Connect it directly to the battery plug. The fan should come on as soon as the battery is connected even if the RX and Tx is off. Works best this way......;533;798;

here are some links to my setup were you can view some of the fan attachments.
Apr 28, 2004, 02:39 AM
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Captain Carlton's Avatar
Two Comments:

I like the fan idea...but the heat sink is also a great value...they complement each other. I had a major crash with one of my Corona yesterday (95 degree day, on the blacktop), and I was hoving at about 50 feet....the ESC kicked i consider that unit more critical. Getting the battery out of the helo helps too...Sling it under with the Voyager E skids.

I cut some additionally holes in the top and bottom of the canpoy. Probably get the fan and aim it at the ESC too.

ps. the crash totalled the skids and battery pack. NO other damage. Amazing. Lucking it was a 3300 Gp pack and not a Lithium.
Apr 28, 2004, 12:11 PM
Registered User
sizam's Avatar
I'll try and find one of those sinks locally, oddly enough aeromicro doesn't carry them (only the spd280 heat sinks) and I'll check the local tech surplus shop for fans. Now that I'm putting a Mega in there I don't want anything bad to happen to the motor.
Apr 28, 2004, 04:07 PM
Registered User
thazy2's Avatar
I agree, both together would be an icee combination. Two is always better than one. You can never have too much cooling.

But if both units are $10 a piece and you needed to choose one, the fan would give you 90% MORE cooling ability.

BTW, that fan i'd mentioned above is only 1inch x 1inch x .40 inch deep. It is very hard to find in local electronic stores. Jameco is the only place that i have seen that offers it in one unit increments.