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BrianG · **Mamba Max vs Quark Observations -** 01.03.2007, 05:09 PM

I was playing around with my Quark 125B and the MambaMax a couple days ago and thought I'd share an interesting observation.

I hooked up batteries to both ESCs, hooked the ESC to a BK Wanderer 10XL and set the transmitter throttle trim so the motor spins slowly. Then, I applied a load (my hand holding the tires) to stop the motor.

On the Quark, it understandably cogs until I let go. Even after a couple minutes, nothing heats up to any noticeable degree.

On the Mamba max, an interesting thing happens. When I first hold the tires, the ESC cogs. However, once the ESC realizes that the rotor isn't moving, it applies more and more power until the tires are ripped from my hands. Once the motor is in motion, the ESC slows back down to whatever throttle level applied by the transmitter. After doing this a few times, the ESC gets noticeably warmer. The motor temperature does not seem to increase much, if at all.

To make sure this wasn't a fluke, I did the same test using the 4600 motor and got the same results, except the MM ESC didn't heat up quite as much.

This is both good and bad. It is good because the Mamba ESC appears smarter and assumes a higher load and increases the power to compensate. But it could be bad if the motor is somehow locked/stalled, or if you are using a large motor. A larger motor could naturally pull more current, and if it is locked/stalled, it could pull way more than is safe for the ESC.

After thinking about this for a while, this phenomenon could be what is causing issues with larger motors in larger vehicles. Maybe even explains why it doesn't seem to like 4 pole motors. The higher load from the weight of the vehicle coupled with the larger motor could be causing strange things in the firmware.

Thoughts?

	(#1)
BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	Mamba Max vs Quark Observations - 01.03.2007, 05:09 PM I was playing around with my Quark 125B and the MambaMax a couple days ago and thought I'd share an interesting observation. I hooked up batteries to both ESCs, hooked the ESC to a BK Wanderer 10XL and set the transmitter throttle trim so the motor spins slowly. Then, I applied a load (my hand holding the tires) to stop the motor. On the Quark, it understandably cogs until I let go. Even after a couple minutes, nothing heats up to any noticeable degree. On the Mamba max, an interesting thing happens. When I first hold the tires, the ESC cogs. However, once the ESC realizes that the rotor isn't moving, it applies more and more power until the tires are ripped from my hands. Once the motor is in motion, the ESC slows back down to whatever throttle level applied by the transmitter. After doing this a few times, the ESC gets noticeably warmer. The motor temperature does not seem to increase much, if at all. To make sure this wasn't a fluke, I did the same test using the 4600 motor and got the same results, except the MM ESC didn't heat up quite as much. This is both good and bad. It is good because the Mamba ESC appears smarter and assumes a higher load and increases the power to compensate. But it could be bad if the motor is somehow locked/stalled, or if you are using a large motor. A larger motor could naturally pull more current, and if it is locked/stalled, it could pull way more than is safe for the ESC. After thinking about this for a while, this phenomenon could be what is causing issues with larger motors in larger vehicles. Maybe even explains why it doesn't seem to like 4 pole motors. The higher load from the weight of the vehicle coupled with the larger motor could be causing strange things in the firmware. Thoughts?