Properly install a gyro in your RC heli, multicopter, or airplane.
RC gyroscopes are single axis devices. You have to read the documentation to figure out where is the axis that it is designed to control. Depending on how this axis is oriented, you then have to mount the gyro with this axis aligned with the axis on the aircraft that you are controlling.
All sensors have to be soft mounted to protect them from vibration. Gyros are no different. Double sided foam tape works great. Look in the package first, since most gyros seem to already come with some tape.
Sensors can also be affected by the temperature changes caused by direct sunlight. If at all possible, mount them inside the model. This is less of an issue with gyros than with other sensors, but it is a good habit to get into.
Carefully align the gyro before pressing down the tape. Being off just a few degrees can make the difference between a great performing gyro and one that just gives you headaches.
The gyro itself is plugged into the receiver channel that you are stabilizing. In turn, the servo or speed control that the gyro is controlling gets plugged into the gyro itself.
A gyro works much better if what it is controlling can keep up with its control signals. A speed control is very quick to react, though the electric motor it controls can take a while to change RPMs. There is not much you can do about that, though.
If the gyro is controlling a servo, I strongly recommend that you use a digital servo. The price difference between analog and digital servos is not nearly as much as it used to be. But digital servos are much better at quickly reacting to small control inputs. That is exactly what a gyro needs to see. Don’t forget to tell the gyro that you are using a digital servo, if it has a setting.
Years ago gyros had only one mode of operation. This mode is now called standard or rate mode. There are very few reasons to use this mode anymore. It can sometimes come in handy during some aerobatic maneuvers. Otherwise it is far inferior to the other mode.
The more sophisticated operating mode is called heading hold mode. Sometimes it is referred to as AVCS mode (angular velocity control system). As the name implies, it is much better at maintaining a given heading or attitude.
Adjustable Travel Volume or Limit Adjustment
Gyros have a potentiometer trim adjustment that controls the limits of the signal that it outputs. Use this to make sure the gyro does not move the servo too far. I don’t think you can damage a speed control or motor by driving it beyond the limits of what it recognizes.
You have to adjust the limit setting using trial and error. After you have made an adjustment, move the aircraft around quickly. If you hear the servo binding, decrease the limit a little bit at a time until it can move freely.
Gain or Delay Adjustment
Another rotary dial on gyros controls how hard it works to maintain the same orientation. If it is set too high, it will overshoot and oscillate back and forth as it tries to find the correct orientation.
If it is set too low, then it will be sloppy and take longer than necessary to correct for drift. Again, you have to use trial and error to find the correct setting.
When you first power up the gyro, be very careful not to move it at all. It needs time to calibrate itself. This calibration period is critical for good performance later.