Digital Trims; Introduction; Advantages Of Digital Trims; The Cruciform Digital Trim System - Multiplex ROYALevo 7 Manual De Instrucciones

12.Digital trims

12.1. Introduction

The meaning of the term "trimming" is as follows:
A model aircraft is required to fly straight and level
when the transmitter sticks are left undisturbed. If this is
not the case, e.g. the model tends to turn in one direc-
tion, the neutral point of the rudder or ailerons can be
corrected (trimmed) to compensate for this.
The ROYALevo7 features a modern digital trim for all
four axes of the primary sticks.
The ROYALevo7 adopts the "Centre Trim" principle, i.e.
trim corrections only affect the central range of the
transmitter control, but not the end-points. The advan-
tage over "standard trims" is that the full travel of the
transmitter control (and thus servo travel) can still be
exploited, as no reserve has to be provided for trim-
ming.
Centre Trim principle
Standard
trim
not
accessible
Bottom
end-point
Standard trimming
The diagram shows that the servo reaches its top end-
point when the stick is moved to the right, but before
the stick reaches its end-point. This means: the stick has
a "dead zone".
When the stick is moved to the left the servo never
reaches its full down-travel. This means: full servo travel
cannot be exploited.
Centre trimming
The servo reaches both its end-points, regardless of the
position of the associated trim.
TIP!
"Centre Trims" alter the response curve of the transmit-
ter control, so you should always try to keep trim correc-
tions to a minimum. If a major correction is required, it is
always best to adjust the mechanical linkage!

12.2. Advantages of digital trims

Digital trims have two important advantages:
1. The trim buttons have no actual mechanical posi-
tion which corresponds to a trim value (cf. a con-
ventional trim with trim sliders). The position of a
digital trim is displayed on-screen, and the trim val-
ues are stored in the model memory. If you switch
model memories, you do not need to move the
trims back to the correct position, as the correct
trim is automatically set.
2. For models which are used with flight phases, the
ROYALevo 7 provides its own trim memory for each
flight phase. Each flight phase can therefore be
trimmed accurately and simply, independently of
the other phases.
Dead zone
Top
end-point
Trim
Stick travel
Untrimmed
ROYAL evo 7 - Instructions
12.3.

The cruciform digital trim system

The trims of the ROYAL evo take the
form of a cruciform set of buttons be-
low and to one side of the stick units.
They are located in the ideal position in
terms of ergonomics, and are easily ac-
cessible when the transmitter is hand-
held or used in a tray.
Every press of a trim button produces a
trim change in the corresponding control axis in the
appropriate direction. If a trim button is held pressed in
for longer than about one second, the trim automati-
cally increments until you release the button again
(AUTO-REPEAT function).
You will hear a beep every time you generate a trim in-
crement. If the trim reaches its centre point, or one of its
end-points, a different sound is emitted to help you
keep track of the trim position. The trim beeps can be
switched OFF and ON (
!
The trim of the fourth stick axis (‡) always af-
fects throttle, and takes the form of a special
idle trim.
This also applies with gliders (and powered gliders)
if this stick controls spoilers, or if it controls collec-
tive pitch on a model helicopter.
12.4.

On-screen trim display

The trim settings are shown in graphic bar-graph form
on both sides and the bottom of status displays 1 - 3.
A maximum of 20 trim increments are available in both
directions, starting from the centre position. The incre-
ment size (trim change / trim step) can be set to either
of two values (0.5% / 1.5%) if required ( TStep
14.1.3.).
!
Note: trim increment size, trim range
When you change the trim increment size, the
number of increments is unchanged; i.e. the
trim range and also the trim value (!) is altered.
This means: if you change the trim increment
size, you must re-trim your model.
The current trim value is shown on the screen in graphic
form, but can also be read off as a numerical value for
each transmitter control (Trim parameter
TIP! Resetting the trim to centre
If you press both trim buttons associated with a particu-
lar stick axis, the trim for the current active flight phase
is reset to centre. This also applies to the throttle trim.
Page 25
13.1.1.).
14.1.2.)