User manual PowerBox Professional
www.powerbox-systems.com 21
The positional values vary according to your linkages, and must be adjusted
to suit your individual model. Clearly it is important to avoid your wheel doors
jamming (striking their mechanical end-stops). The timing values shown here
should also be set to suit your requirements. The task numbering does not
need to coincide with the timed sequence; for example, Task 5 could be set
to run before Task 2.
Our example clearly shows how the function is built up. Additional mo-
vements or intermediate stops when the doors open or close can be added at
any time; all you need is to set up a new free task. Viewed overall, there is now
no reason at all why the retraction and extension of the undercarriage in the
model should not exactly emulate that of the full-size aircraft. In other words:
you can give free rein to your imagination.
Note: if you wish simply to switch servos or valves on or off, you must
always enter a time difference in the sequence, as the door sequencer
needs a small amount of time to carry out its calculations. The following
is an example for a retract valve:
The time lag of 0.1 s is sufcient, and is virtually unnoticeable in practice.
Important: the rst START POSITION at UP » DOWN must always coincide
exactly with the last STOP POSITION of DOWN » UP. This simply means that
the last task must cause the servo to return to its starting value, regardless
of any individual intermediate steps you create! If the wheel door servos carry
out unusual or unexpected movements when you try out the programmed
sequence, please check your tasks!