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Old 04-09-2008, 12:01 AM   #1
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Default mamba 6900 on 3S lipo

can i run the 6900 mamba on 3S lipos, limiting the RPM by adjusting the Throttle End Points on my transmitter? thanks...
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Old 04-09-2008, 02:37 PM   #2
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I would not try it(although possible), there is still a great chance for failure. I would stick with the 5700 on 3s, its still wicked fast
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Old 04-09-2008, 03:50 PM   #3
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I would think it would be possible if you set your epa low enough?

Or if you are just going to run it for like 5 seconds or less at a time
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Old 04-09-2008, 04:53 PM   #4
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I'm not sure of the exact reason, but heli guys who fly brushless motors have found that limiting RPM by running less than around 80% throttle or so at the transmitter tends to get the speed control into thermal issues.

I believe it's something to do with the effiency going down at partial throttle settings, but I'm not certain of the exact reason. I do know that heli flyers tend to spool up to RPM and maintain it for the whole flight, while we're on and off the throttle constantly, so maybe it wouldn't even be an issue for us... I'd ask someone at Castle to be sure.
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Old 04-09-2008, 11:21 PM   #5
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thanks guys the car will be just for speedruns. i already have the Max and the 6900 and shipping thing in is quite hard these days for an additional 5700 motor.
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Old 04-10-2008, 12:42 AM   #6
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Another thing that you could do is put a fan (or two) on the esc.
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Old 04-10-2008, 02:00 PM   #7
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Quote:
Originally Posted by Trips View Post
I'm not sure of the exact reason, but heli guys who fly brushless motors have found that limiting RPM by running less than around 80% throttle or so at the transmitter tends to get the speed control into thermal issues.

I believe it's something to do with the effiency going down at partial throttle settings, but I'm not certain of the exact reason. I do know that heli flyers tend to spool up to RPM and maintain it for the whole flight, while we're on and off the throttle constantly, so maybe it wouldn't even be an issue for us... I'd ask someone at Castle to be sure.

Limiting the endpoint does cause a loss of effecincy, but it shouldnt be too much of a problem on the mamba max. The real issue he will run into with the 6900 and 3s is damaging the rotor from turning so many rpm's. If he was going to do it, id start with the timing all the way down and a small pinion/big spur to try to keep everything in check. another reason not to lower the endpoint is that it makes the throttle choppier and not as smooth.
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Old 04-10-2008, 05:16 PM   #8
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www.nitrokillers.com - there are guy has run it but, you need to lower your pinion.
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