RC-Monster Forums - View Single Post - Here's a question for the Brushless experts

BrianG · 08.29.2007, 04:28 PM

Caps will only charge up to the battery voltage and do not present any kind of load to the battery by themselves once charged up (and that takes milliseconds).

What is probably happening is that your throttle trim is set so it is sending enough voltage to the motor to draw current, but not enough to make it turn under load - essentially "on" a tiny bit. Try removing the pinion and see if the motor doesn't turn. I suspect it will since there is no more load (simply from the drivetrain) holding the motor back. Then, adjust your throttle trim slightly until the current drops to near 0 and/or the motor stops.

That said, 4-5A should be enough to make the motor turn regardless of load. At only 2s, that's between 30W and 37W of power being sent somewhere. If the motor isn't drawing the power, the ESC must be and something should be getting at least warm.

Either that or your eagletree unit is miscalibrated and is seeing a current that is not there, which is weird since it uses a hall-effect sensor for current (as opposed to a series shunt resistor to measure V drop).

	(#3)
BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	08.29.2007, 04:28 PM Caps will only charge up to the battery voltage and do not present any kind of load to the battery by themselves once charged up (and that takes milliseconds). What is probably happening is that your throttle trim is set so it is sending enough voltage to the motor to draw current, but not enough to make it turn under load - essentially "on" a tiny bit. Try removing the pinion and see if the motor doesn't turn. I suspect it will since there is no more load (simply from the drivetrain) holding the motor back. Then, adjust your throttle trim slightly until the current drops to near 0 and/or the motor stops. That said, 4-5A should be enough to make the motor turn regardless of load. At only 2s, that's between 30W and 37W of power being sent somewhere. If the motor isn't drawing the power, the ESC must be and something should be getting at least warm. Either that or your eagletree unit is miscalibrated and is seeing a current that is not there, which is weird since it uses a hall-effect sensor for current (as opposed to a series shunt resistor to measure V drop).