BFF CL Software - Short User Guide


Previous    Contents     Next

Appendix I. BFF Motorised Trim Wheel.

The CL Software includes support for the BFF Motorised Trim Wheel. Use Tab 7 Item 25 in the Configuration Manager (v2+) to enable the MTW support. For more details of the MTW see -

The Motorised Trim Wheel acts in the elevator axis only and is active only for modes in which the CL system has elevator trim authority.

To enable the MTW support:

  1. Set Tab 7 Item 25: Enable Elevator Motorised Trim Wheel = 1
  2. Ensure that trim button input is set for the elevator axis: Set Tab 7 Item 1 = 2.

    The CL software will actually ignore the assigned button input but the setting will allow it to output trim wheel position demand when A/P is engaged and so allow the trim wheel to move to simulate the axis unloading.

    The BFF Trim Wheel Controller software can be set to read the trim input buttons directly to provide an electric trim capability.
  3. Set Tab 7 Item 16: Elevator Auto-Trim Enable = 25

    This is a technical setting,  it is used by the BFF Trim Wheel Software to adjust the position following sensitivity of the trim wheel.

    It sets the position error at which the Proportional term of the position following algorithm produces maximum response speed. Increasing the value softens the MTW response to A/P trim movements by allowing bigger errors before max speed is attained.

    A value of 25 is recommended for the setting. Sensitivity can be more directly adjusted using the MTW software settings.



When the motorised trim wheel is active the CL system will accept elevator trim adjustment by manual turning or button induced movement of the trim wheel. The trim adjustments will have the same effect on stick loading as normal.

When A/P pitch control is engaged the trim wheel will rotate automatically under control of the CL software. The movement auto-trims the elevator axis whilst the stick follows A/P pitch control actions. This simulates unloading of A/P servos acting on the stick, and the result is an active trim movement of the wheel whilst A/P is active. It also results in a force balanced stick when A/P is disengaged which gives a smoother A/P disengage transition to manual flight control.

Flying with an integrated motorised trim wheel provides a more complete simulation pitch control simulation.

The motorised trim wheel support is enabled internally only when the CL system has elevator axis trim authority. This is the case in most flight modes, however Heavy Jet Mode 1 and when CL system trim is manually switched OFF are two examples of when elevator trim authority stays with the flight sim software. In these modes the trim wheel software can work directly with the flight sim instead.


Previous    Contents     Next

Copyright 2018 BFF Design Ltd All Rights Reserved.