User Manual

D = differential: in this case the corrective output value is affected by the rate of change of the
input value, i.e. the faster the model tilts around the axis, the more pronounced the corrective
response of the gyro. If the model changes attitude very gently, then the D factor causes
hardly any corrective action. It also makes absolutely no difference how far the model has
already changed attitude; the crucial value is only the speed or rate of the movement. The rate
of change is again multiplied by a factor (as with P correction) to produce the output value. For
this reason pure D correction is not used; it must always be employed in combination with P
correction.
4.1 Programming PID correction - Gyro settings display:
Aileron / Elevator / Rudder: shows the programmable P factors for the corresponding control
surface.
Note: the gyro axes must first be defined under New settings (see section 3.4).
If you wish to disable the gyro, enter the value OFF in the appropriate control function.
P factor:
The P factor should always be set first, followed by the D factor (adjustment range in each
case 0 to 10). A general rule is that the larger the control surface, the smaller the P factor
required. Start with a factor of 2 (default setting), and do not exceed 4 - 5 as maximum value
for the normal flight phase, 2 - 3 for speed, 3 - 6 for landing; the maximum value of 10 should
be reserved for torque-rolls only.
Note: the higher the model’s speed, the more quickly oscillation may set in.
D factor: for a given P factor setting, the model’s tendency to oscillate can be reduced by
setting a lower D factor. However, if you select a lower setting for the P factor, then you may be
able to set a higher D factor value before the onset of control surface oscillation. The gyro
effect can be optimised by fine tuning the D factor.
Note: the standard P and D values should cause the gyros to correct the model’s attitude
quickly when it is upset by an outside influence, without causing oscillation, but in practice
the optimum values for a particular model can only be found by flight-testing. If the model
displays little or no automatic stabilization with the default settings, the value should be raised;
on the other hand, if the model oscillates (wave-like movements in flight), the value should be
reduced. If your transmitter has spare proportional controls, you can use them to adjust the
values while the model is flying. Some transmitters allow the corrective factors to be altered
during a flight using the proportional controls, whereas others allow fixed values only.
4.2 Programming the factors
4.2.1 Programming, transmitter with proportional controls
If your HoTT transmitter is equipped with proportional controls, it is also possible to adjust the
P and D factors for each axis during a flight: what you might call ‘flying the settings’. You need
to assign proportional controls (e.g. the sliders on the mc-20) to any channel in the range 5 to
16 (in this example channel 9); now you can alter the P factor (and the D factor) using these
controls. In each case the current values are shown in brackets.