Greyhead

A heading–hold gyro is definitely the answer for any model that has poor ground handling. The gyro generates a signal when it is moved in a particular plane, not a model plane but horizontally for example. By mounting the gyro accordingly it can monitor yawing, pitching or banking, in this case we use yaw and set the gyro to apply opposite rudder.

A standard gyro only generates a signal while the model is actually moving in the monitored plane but as this correction signal is virtually instantaneous it is quite adequate to smooth out any affect from gusty wind conditions in the air and would possibly be OK on the ground if taking off from smooth Tarmac. Taking off from grass is another matter all together and “ground looping” often occurs before the model has gained enough speed for the rudder to be very effective.

A heading–hold gyro “remembers” it’s orientation as it is switched on and holds the signal until it returns to it’s original heading; they obviously have to be able to be switched on/off using a spare channel otherwise the model would take off and fly straight until it was out of range!

In practice the model is switched on with the gyro switched off at the TX, when ready for take off the model is pointed directly into wind and the gyro switched to “heading-hold”; as soon as the model is airborne the gyro is either switched off or to “standard mode” if the wind is a bit gusty. If the model needs rudder as well as aileron to turn then the gyro needs to be off for the model to turn satisfactorily so in gusty weather there is a lot of “switch throwing” to be done.

As yet I’ve never landed using the gyro as “ground looping” isn’t such a problem as the model is slowing down and isn’t about to leap into the air cross wind but I see no reason why the gyro shouldn’t be used, it would certainly make for a dead straight landing approach!



Barry

If you think this post would be more suitable for a different forum (tutorial??) feel free to delete this last bit and move the rest.

Grahame