Hi guys my pdb burned up,how can i check the motors to see if they work before rebuilding the quad. I have an idea of connecting a 12v. bat. directly, is that a good idea they don't look burned.
         THANKS 

Unfortunately you can't just connect brushless motors up to a voltage to check if they work or not because they are 3-phase motors requiring pulsed voltage phases.

You either need to connect them to another ESC which in turn is connected to a flight controller to test them, or you will need to use a "Servo Tester" and an ESC which will provide the require phased voltages to the motor to make it spin. Either way you're going to need a working ESC in order to test a brushless motor.

Lee has a good explanation about how ESCs use phased voltages to control a motor in the video below. Everything up to about the 6 minute mark should be enough to show you how things work. Beyond that it starts getting into ESC firmware capabilities and types.

(02-Dec-2019, 03:29 PM)SnowLeopardFPV Wrote: Unfortunately you can't just connect brushless motors up to a voltage to check if they work or not because they are 3-phase motors requiring pulsed voltage phases.

You either need to connect them to another ESC which in turn is connected to a flight controller to test them, or you will need to use a "Servo Tester" and an ESC which will provide the require phased voltages to the motor to make it spin. Either way you're going to need a working ESC in order to test a brushless motor.

Lee has a good explanation about how ESCs use phased voltages to control a motor in the video below. Everything up to about the 6 minute mark should be enough to show you how things work. Beyond that it starts getting into ESC firmware capabilities and types.

Thank you my freind you are allways helping out.

You can actually check your motor without ESC. Little bit cruel, but works.

you could physically inspect the windings by removing the bell and looking... when the coating on those windings burns its its usually very obvious, they bubble up almost and turn a dofferent color and smell bad... even if they havent smoked.... its obviously not 100% though but if you jist need that extra little push of confidence this could do it for ya.