Please consider supporting me via Patreon at: https://www.patreon.com/thedroneracingengineer
There aren’t very many easy ways to tell whether a quadcopter motor is damaged. Lots of times, they look fine, but drop out of the air. Is it the motor? Is it the ESC? Here’s a cool trick for testing a quadcopter motor using a drill and a multimeter.
The tachometer that I use is: http://amzn.to/2rIMYti
The multimeter that I use is: http://amzn.to/2nb1cAs
MANDATORY DISCLAIMER: I am a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for me to earn fees by linking to Amazon.com and affiliated sites.
Amzn.to links above are affiliate links, and I will receive compensation if you use them.