Sailplane Trimming Chart - FUTABA 8UHPS Instruction Manual

SAILPLANE TRIMMING CHART

To test for _
1. Model Control Fly the model straight
Neutrals and level
2. Control Throws Fly the model and apply
full deflection of each
Note: be sure all control in turn. Camber
aileron & flap control in neutral (setup
horn pairs have 6 & 9).
matching angles
3. Decalage & Center Trim for level glide.
of Gravity (Note: Enter 45° dive (across
this is an iterative wind if any). Release
procedure, depends controls when model
on desired handling vertical. CAUTION:
characteristics. beware of airspeed &
Aft CG = less flutter.
stability but better
performance)
4. Butterfly Glide Fly the model and apply
Path Control full deflection of glide
Settings path control (usually
(Part 1) throttle stick). Observe
Note: be sure all any pitch changes.
aileron & flap
horn pairs have
matching angles.
4. Butterfly Glide Fly the model and apply
Path Control full glide path control.
Settings Observe any roll motion.
(Part 2)
5. Fly the model and apply
Differential/Coupl alternating left & right
ed Rudder setting aileron commands.
Observe path of fuselage
line (p. 51).
6. Camber (full wing Put the model in a
aileron & flap straight glide passing in
droop or reflex) front of you. Apply
setting camber control.
7. Launch Settings Switch to Launch mode.
(Part 1) Launch the model &
observe climb angle and
required control inputs
8. Launch Settings Switch to Launch mode.
(Part 2) Launch the model &
observe climb angle and
required control inputs
9. Speed Settings Switch to speed mode
(entire TE reflexed
slightly, no more than
1/16" or 1.5 mm)
10. Elevator-to-Flap Fly model at high speed,
Coupling Setting bank & pull up
*Note: Swept wing planform may cause opposite reactions, so experiment until proper behavior is attained
Test Procedure
Adjust the transmitter trims for
hands-off straight & level flight, no
camber control.
Check the model's response to each
control input. Set flaps for as
much down flap as possible in glide
path control (90° is good) <5° reflex
needed.
A. Does the model continue its
dive without pulling out or
diving?
B. Does the model start to pull out
(nose up)?
C. Does the model start to tuck in
(nose down)?
A. Nose drops, up elevator
required for level flight
B. No pitch change
C. Tail drops, down elevator
required to maintain level flight
A. Model rolls to right when glide
path control (throttle stick)
activated
B. No roll motion
C. Model rolls to left
A. Model yaws to right with left
aileron and vice versa
B. Fuselage traces straight line
C. Model yaws to left with left
aileron and vice versa
A. Model slows down & stalls or
sinks rapidly
B. Model slows slightly
C. Model speed unchanged
A. Shallow climb angle; lots of up
elevator required
B. Model climbs steeply with little
control input needed
C. Too steep climb, weaves back
& forth, down elevator required
A. Model banks left on tow
B. Model climbs straight ahead
with no roll input needed
C. Model banks right on tow
D. Model tip stalls to one side
A. Nose drops
B. No pitch change
C. Tail drops
A. Model keeps speed
B. Model slows down
©1995 by Don Edberg (all rights reserved)
Observations
85
Adjustments
Change electronic subtrims and/or
adjust clevises to center transmitter
trims.
• Aileron & elevator rates: set for
desired authority
• Rudder: set for max throw
• Set flap motions in Steps 4, 5, & 9.
A. No adjustment
B. Reduce incidence (add down
elevator) and/or reduce nose
weight
C. Increase incidence (add up
elevator) or add nose weight)
A. Several options:
1) more up elevator mixing;
2) reduce aileron reflex*;
3) increase flap motion*
B. No adjustment
C. Reverse of A
A. Mix in less right & more left
aileron reflex with throttle
motion
B. No adjustment
C. Reverse of A
A. Increase differential and/or
amount of rudder coupling
B. No adjustment
C. Reduce differential and/or
amount of rudder coupling
A. Reduce amount of droop
B. No change needed
C. Increase droop amount
A. Move towhook rearwards small
amount, increase up elevator
preset a little
B. No adjustment
C. Move towhook forward,
increase down elevator preset
A. Reduce left ail & flap droop or
increase right ail & flap droop
B. No adjustment
C. Reverse of A above
D. Be sure droop same on both
sides. Increase aileron droop
or decrease flap droop (no typo)
A. Increase up elevator preset
B. No adjustment
C. Reverse of A
A. Increase down flap
B. Decrease down flap
.