User Manual

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Figure 7 – Guardian Gain Control Dials

take off with power.

Once in the air and only when safe, release the control stick so it sits at zero deflection with 2D Mode enabled. Your airplane should fly

straight and level. If not, your Guardian may be mounted improperly or you need to re-trim your airframe. Disable stabilization by

flipping the Mode/Config switch to the center position (if available). Trim your controller in this mode until the plane achieves level

flight. Land and follow the instructions for “Resetting Trims” on the ground.

Tuning Stabilization Gains

Stabilization Theory

The Guardian 2D/3D Stabilizer uses accelerometers and gyroscopes to measure the orientation of your model relative to the local

direction of Earth’s gravity. In addition, it interprets Pitch and Roll attitudes commanded by your Elevator and Aileron stick movements,

respectively.

With this information, it is able to determine the error between your requested flight attitude and your plane’s true orientation. By passing

this error through a controller algorithm and sending it as servo commands through its Elevator, Aileron and Rudder outputs, the Guardian

can help turn your squirrely model into a smooth-flying wing on rails!

Each axis has a separate gain control dial, which is used to adjust gain on that axis. The Pitch, Roll and Yaw gains are then scaled by the

optional overall “Master Gain” control, which can be mapped to a knob (or slider) on your transmitter. This arrangement allows

individual axis gain adjustment while also providing in-flight overall gain adjustment to compensate for varying conditions and

aerodynamic performance.

In general, the higher the gain, the more responsive and resilient your plane will be to disturbances such as wind, balance and trim issues.

Tuning the gains too high however may result in oscillations of the airframe. It is recommended that the Master Gain control be used to

tune the airframe until it barely oscillates and then be turned back down. This will ensure the best performance while preventing future

oscillations.

Individual Axis Gain Dials

The gain control dials on the Guardian can be used for tuning the individual axes on your airframe. In addition, they allow for the

reversal of the direction of stabilization servo travel. When a dial is centered (with the

“double-dot” dial indication facing upwards, as shown in Figure 7) the gain for that axis is

set to zero. This effectively disables stabilization on that axis.

Note: If you have difficulty seeing the double-dot indication on the dials, you can either

gently rotate the dials counterclockwise and clockwise to find the approximate center point,

or you can use the PC software to visualize the dial settings on your computer screen.

When a dial is rotated away from its centered position in the clockwise direction, the gain

for that axis is increased, and the stabilization deflection direction is set to normal. If the

dial is rotated counterclockwise from its centered position, the gain will be increased as well, but the stabilization deflection direction will

be reversed. This allows for stabilization to be tuned for any airframe, regardless of servo orientations.

Stabilization “Master Gain” Control

The Guardian’s Gain input channel, when mapped to a knob (or slider) on your transmitter, serves as a Master Gain control. The Master

Gain multiplies the individual Pitch/Roll/Yaw gains and serves as a way to easily tune all three. If you have an RC controller that has an

analog knob, this can be mapped to the Gain channel to allow for in-flight stabilization gain adjustment. The higher the gain knob setting,

the stronger the Guardian’s stabilization effect will be.

The knob gives the ability to transition smoothly from stabilized flight to un-stabilized flight. Additionally, since changing airspeed can

change your airframe’s flight characteristics, it is often helpful to be able to tune the controller in real-time. When this feature is used

with 2D mode, the stabilizer’s control characteristics vs. the Master Gain control’s position is as follows:

• -100

% (1.1ms servo pulse):

Stabilization is OFF.

• -99% to ~0% (depending on Pitch/Roll/Yaw gain values): Medium Stabilization. As the Gain knob is

increased from -100% deflection, the model becomes more stable. Depending on your knob selection

however, the model may still be rolled by strong stick movements or turbulence

• ~0% to 100% (1.9ms servo pulse, 200% Overall Gain): Maximum stabilization. The model should not roll

over

when in this range. Servo commands will become exaggerated, leading to tighter control of the plane.

Oscillations may occur depending on the airframe.

The ranges given above apply when the Guardian gain dials are set to about +/-50° from centered.

Warning: Be careful while tuning the Master Gain. Some airframes may oscillate very strongly at higher gains, possibly

damaging themselves or becoming uncontrollable. To avoid strong oscillations, increase the Master Gain slowly and reduce it as

soon as oscillations are noticed.

Note: If the individual axis gain dials are set to lower values, the effect of the Overall Gain knob will be reduced, and vice versa.

Note: If no connection is made to the Guardian’s Gain input, 100% Overall Gain will be used.