FUTABA 8UHPS Instruction Manual page 68

The following chart may be used to systematically set up and trim a model for straight flight
and aerobatic maneuvers. Please note that for best results, trimming should be done in near-
calm conditions. Before you decide to make a change, be sure to try the test several times
before making adjustments. If any changes are made, go back through the previous steps
and verify that they are not also affected. If they are, make further adjustments as necessary.
To test for _ Test Procedure
1. Control Fly the model straight and level
neutrals
2. Control Fly the model and apply full
throws deflection of each control in turn
3. Decalage Power off vertical dive
(crosswind if any). Release
controls when model vertical
(elevator trim must be neutral)
4. Center of Method 1: Roll into near
Gravity vertically-banked turn.
Method 2: Roll model inverted
5. Tip Fly model straight & level
weight upright. Check aileron trim
(coarse maintains level wings. Roll
adjustment) model inverted, wings level.
Release aileron stick.
6. Side Fly model away from you into
Thrust & any wind. Pull it into a vertical
Warped climb, watch for deviations as it
Wing slows down.
7. Fly the model on normal path into
Up/Down any wind, parallel to strip, at a
Thrust distance of around 100 meters
from you (elevator trim should be
neutral as per Test 3). Pull it
into a vertical climb & neutralize
elevator
8. Tip Method 1: fly the model as per
weight (fine Test 6 and pull into a reasonably
adjustment) small diameter loop (one loop
only)
Method 2: fly the model as per
Test 6 and then push into an
outside loop (one only, fairly
tight)
Observations
Use the transmitter trims for hands-
off straight & level flight.
Check the response of each control
• Aileron high-rate: 3 rolls in 4
seconds; low-rate: 3 rolls/6 sec
• Elevator high-rate: to give a smooth
square corner; low-rate gives approx.
130 ft diameter loop
• Rudder: high-rate 30-35° for stall
turns; low rate maintains knife-edge
A. Model continues straight down
B. Model starts to pull out (nose
up)?
C. Model starts to tuck in (nose
down)?
A1. Nose drops
B1. Tail drops
A2. Lots of forward stick (down
elevator) required to maintain
level flight
B2. No forward stick (down
elevator) required to maintain
level flight, or model climbs
A. Model does not drop a wing.
B. Left wing drops.
C. Right wing drops.
A. Model continues straight up.
B. Model veers left
C. Model veers right
D. Model rolls right
A. Model continues straight up
B. Model pitches up (goes toward
top of model)
C. Model pitches down (goes
toward bottom of model)
A. Model comes out with wings
level
B. Model comes out right wing low
C. Model comes out left wing low
65
Adjustments
Change electronic
subtrims or adjust
clevises to center
transmitter trims.
Change ATV (for high
rates), and Dual Rate
settings (for low rates)
to achieve desired
responses.
A. No adjustment
B. Reduce incidence
C. Increase incidence
A. Add weight to tail
B. Add weight to
nose
A. No adjustment
B. Add weight to
right tip.
C. Add weight to left
tip.
A. No adjustment
B. Add right thrust
C. Reduce right thrust
D. Put trim tab under
left wing tip *
A. No adjustment
B. Add down thrust
C. Reduce down
thrust
A. No adjustment
necessary
B. Add weight to left
tip
C. Add weight to
right tip