User manual

262
Program description - Ring limiter
Ring limiter
Control of Voith Schneider propellers in model ships
This option is available as standard on the
mc-20 HoTT transmitter only.
Scroll with the selection keys on the left or
right four-way button to the menu option
»Ring limiter« in the multi-function menu:
Trim memory
Telemetry
Channel sequence
Multichannel
Ring limiter
MP3 player
Tap briefly on the center SET key of the right four-way
button to open this menu option:
4
4
4
Ring limiter
Input
SET
3
9
11
OFF
OFF
OFF
Output
X
3
3
3
Y Y
4
10
12
X
This »Ring limiter« menu point is available as
standard on the mc-20 HoTT transmitter only, and
is primarily intended for controlling a maximum of
three Voith-Schneider power systems as employed
in model boats. These are positioned beneath the
ship where they are exposed to a free flow of water
in all directions. The control of these drives and turn-
ing their vertically oriented propeller blades is done
with two servos per Voith Schneider propulsion unit
whereby, for mechanical reasons, the propellers of
this type offered by Graupner under order nos. 2358
and 2358.BL have a maximum control travel limitation
of 4 mm each.
As long as the sticks for forward/reverse and left/
right are operated individually (see section “Column
Input”) this is no problem because travel for the two
servos can be appropriately adjusted, both mechani-
cally as well as in the »Servo adjustment« menu.
However, this becomes problematic when, for ex-
ample, one stick is 100 % forward and, at the same
time, the other stick is pushed completely to the right
to arithmetically produce a 141 % sum for the two
servo travel vectors. The mechanical controls of the
Voith Schneider propellers will collide with their limits;
in best case only drawing an unnecessary amount
of electric current, in worst case causing damage or
even bursting the linkage..
This problem can be circumvented by using “ring
limiters”, which are featured as standard on the
mc-
20 HoTT transmitter, and can be unlocked on the
mc-16 HoTT transmitter as an extra-cost option.
There are a maximum of three “ring limiters” available
in the “SET” column of this option’s first display page
(see figure at left) that can be switched “ON” or “OFF”
individually. In the first line on the setting page for a
given “ring limiter”, its maximum travel can then be
set for a range of between 25 and 125 %. The second
line provides a setting for the size of limitation of over-
all deflection between:
0 % circular limit ()
100 % no limit ()
(limitation is strictly a matter of the given stick’s
mechanical stop)
Important notice:
When this function is used, leave the respective
setting values in the »Dual Rate / Expo« and
»Servo adjustment» menus at 0 and 100 % or
reset them back to their default values.
The adjacent sketch illustrates
the effect for a 0 % setting. The
cross-hatched area of travel is
curtailed and appears as a “dead
zone”.
Column, “Input”
With the standard preset control mode 1, all three
ring limiters are pre-assigned to inputs 3 (forward/re-
verse) and 4 (left/right) which are actuated by the left
stick. However, this pre-assignment can be replaced
anytime by any other transmitter control combination.
Use the selection keys on the left or right four-way
button to move the marker frame to the desired value
field then briefly tap the center SET key of the right
four-way button:
4
4
Ring limiter
Input
SET
3
9
11
OFF
OFF
OFF
Output
X
3
3
3
Y Y
4
10
12
X
4
Select the desired control channel (1 … 12 max.)
for the value field now displayed in inverse video by
using the  or  selection keys. However, do not
forget that if a control channel in the range of 5 … 12
max. is selected, it must also be assigned to a con-
trol in the »Control adjust« menu, see page 118.
Briefly tap the center ESC of the left four-way button
or the center SET key of the right four-way button to
conclude your entry.
In principle, the other inputs are to be handled in the
same manner.
A tap on the  or  keys of the right four-way
button at the same time (CLEAR) will reset the active
value field back to its given default value.
Column, “Output”
The three ring limiters are pre-assigned to receiver
outputs 3/4, 9/10 and 11/12 by default, whereby the
outputs in column “X” are for the forward/reverse func-
tion and the outputs in column “Y” are for the left/right
function. However, this preset combination of receiver
outputs can be replaced as necessary by any other
mc
 
16 20