No, I've never done it, but for a start I'd use a scope to check what you actually get on the supply rails, so you know what sort of levels you need to amplify.
Most 5 pole motors used in the RC hobby are for servo motors, and there aren't even many of those. The motors that actually produce the power for moving are almost exclusivly 3 pole motors, or DC brushless, but those are mostly used in aircraft.
You could do it if the meter supported a frequency measurement mode. Place a magnet on the device to be measured (or two or more to maintain ballance) and make a coil to feed into the meter. It really depends on the voltage required to trigger the meters frequency measurement.
You could do it if the meter supported a frequency measurement mode. Place a magnet on the device to be measured (or two or more to maintain ballance) and make a coil to feed into the meter. It really depends on the voltage required to trigger the meters frequency measurement.
But is there a way to read RPM with no Pickup. There is a power supply in out hoppy that will show you Voltage Amperage and RPM for a motor and all there is two wires hooked up to the motor.
Sure, but I have no idea how to implement it practically though, or of any meters that have the feature. Basically it reads the back EMF during commutor switching to determine RPM. But it wouldn't work with a brushless motor.