09 Motor testing
Now that your LadybugFC is all wired up, it's time to test it with some brushed DC motors.
The cardinal rule of motor testing is: REMOVE PROPELLERS BEFORE TESTING. Although the little DC motors and props you use with LadybugFC are unlikely to cause the kind of serious injury you can suffer by ignoring this rule on a larger vehicle, testing with props on can still hurt you and snag delicate wires. So if you're trying out your LadybugFC on an already-assembled vehicle, remove the #$%@ propellers now!
Although you can use the LadybugFC with any brushed-motor quadcopter, we're going to use a modified version of the classic 3D Fly frame from Hovership, Inc. We added a little block in the center to allow you to mount the LadybugFC (or other micro FC) easily, with double-sided VHB tape, providing enough clearance to plug in your USB cable. This frame is made for the popular 8.5x20mm motors used in the Hubsan X4 and similar entry-level vehicles. Like the higher-performance brushed DC motors available today, these motors have a connector that will plug into the Molex connectors that we soldered onto the LadybugFC earlier.
Here is the frame with the LadybugFC and motors attached, ready for testing:
Note the orientation of the board (USB at rear) and that motors 1 (right rear) and 4 (front left) are clockwise-spinning, with red/blue wires, and motors 2 (right front) and 3 (left rear) counter-clockwise, with black/white wires. For greater clarity, we've also removed the receiver from its cable.
Once you've got your vehicle set up like this with the Ladybug powered by the battery and talking to your computer over USB, you can use Hackflight GCS to test the motors. After clicking Connect, click the Motors button. Click the little checkbox to confirm that you've (wait for it ...) REMOVED THE PROPELLERS, and you'll see an image like this:
Now you can click on the location of each motor and use the slider to run the motor from 0% through 100% of its speed range (though there's probably no reason to go above 50%). By placing your thumb on the motor shaft as it is spinning, you can ensure that the motor is spinning in the correct direction described above.
As before, if you prefer not to use the Ground Control Station, we've provided a sketch (File/Examples/Hackflight/motortest) that you can use to test the motors. By un-commenting each MOTOR_PIN declaration at the top of the sketch, you can spin each motor separately.
Next: Maiden flight