kamakazi

My Feedback: (1)

Where does the music come from, is there a speaker in the electric motor . The 1st time I hooked up my ESC and ran my motor strange sounds came out of the motor. And I fried my BEC cause I didnt put an ammeter in the circuit. It drew a bunch more amps than it shoudda. And that brings up another question, can I just use the "clip around" feature on an ammeter on one of the motor wires. Otherwise i would have to get me some kind of ammeter that I could put in the circuit with the battery and motor.

whitecrest

The motor casing is acting like a speaker energized by the stator coils. My ESCs generate very loud music occasionally. I wish I could turn it down sometimes.

For the total draw, you want to measure the current being supplied to the ESC. This will allow you to measure current being drawn by all the electronics (ESC, servos, receiver) as well as the motor as it is being throttled. If you exercise your servos with the motor off, you will have a good idea of the load demanded of the BEC.

Some of the latest DVOMs can measure 10-amp currents continuously and up to 20 amps for about 15 seconds at a time. Put the meter in the positive (red) wire to the ESC. It is also possible to use a shunt resistor in the positive lead and measure the voltage drop across it with your DVOM to easily calculate the current draw. A wattmeter will give you the applied voltage, current and input power on one display and is probably the most elegant solution.

Rodney

If you plan to continue in electric powered flight, you should buy yourself a wattmeter as they are absolutely necessary if you want to get the most out of your equipment without destroying something.  As to a clamp on ammeter, yes you can use them but measure the current out of the battery, not on one of the motor wires if you are using brushless motors.  A clamp on ammeter is more expensive than the wattmeter and, at low currents may be more inaccurate.  Also, a clamp on ammeter that will measure DC is not easy to find, I got mine at Sears.

Sir Raleigh

Here's a DIY project you can build until or if you decide to get a Wattmeter:

Mini-HowTo - $3 Wattmeter

Bill