65
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
Observations
Adjustments
1. Control
neutrals
Fly the model straight and level
Use the transmitter trims for hands-
off straight & level flight.
Change electronic
subtrims or adjust
clevises to center
transmitter trims.
2. Control
throws
Fly the model and apply full
deflection of each control in turn
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
Change ATV (for high
rates), and Dual Rate
settings (for low rates)
to achieve desired
responses.
3. Decalage
Power off vertical dive
(crosswind if any). Release
controls when model vertical
(elevator trim must be neutral)
A. Model continues straight down
B. Model starts to pull out (nose
up)?
C. Model starts to tuck in (nose
down)?
A. No adjustment
B. Reduce incidence
C. Increase incidence
4. Center of
Gravity
Method 1: Roll into near
vertically-banked turn.
Method 2: Roll model inverted
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. Add weight to tail
B. Add weight to
nose
5. Tip
weight
(coarse
adjustment)
Fly model straight & level
upright. Check aileron trim
maintains level wings. Roll
model inverted, wings level.
Release aileron stick.
A. Model does not drop a wing.
B. Left wing drops.
C. Right wing drops.
A. No adjustment
B. Add weight to
right tip.
C. Add weight to left
tip.
6. Side
Thrust &
Warped
Wing
Fly model away from you into
any wind. Pull it into a vertical
climb, watch for deviations as it
slows down.
A. Model continues straight up.
B. Model veers left
C. Model veers right
D. Model rolls right
A. No adjustment
B. Add right thrust
C. Reduce right thrust
D. Put trim tab under
left wing tip *
7.
Up/Down
Thrust
Fly the model on normal path into
any wind, parallel to strip, at a
distance of around 100 meters
from you (elevator trim should be
neutral as per Test 3). Pull it
into a vertical climb & neutralize
elevator
A. Model continues straight up
B. Model pitches up (goes toward
top of model)
C. Model pitches down (goes
toward bottom of model)
A. No adjustment
B. Add down thrust
C. Reduce down
thrust
8. Tip
weight (fine
adjustment)
Method 1: fly the model as per
Test 6 and pull into a reasonably
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)
A. Model comes out with wings
level
B. Model comes out right wing low
C. Model comes out left wing low
A. No adjustment
necessary
B. Add weight to left
tip
C. Add weight to
right tip
