pushrod 1/8" [3.2mm] from the rear of the float. Cut the
inner and outer pushrods at the marked location.
❏
6. Disconnect the pushrod clevis from the rudder control
horn and pull the inner pushrod out a few inches. Cut the
outer pushrod 3/8" [9.5mm] from the end (at the float end).
Reconnect the clevis back to the control horn.
❏
7. Thread the 2-56 x 6" [152mm] wire 13 turns into the
inner pushrod. Insert the wire into the screw-lock connector
on the water rudder control arm and cut the wire to length.
❏
8. Attach the pushrod assembly to the rear of the float
with a nylon strap and two #4 x 1/2" [12.7] screws and two
#4 flat washers.
❏
9. Center the rudder and tighten the screw on the
screw-lock connector.
Note: Two additional nylon straps and screws are included if
additional support is needed.
❏
1. Turn on the transmitter and receiver. With the rudder
centered, adjust the water rudder linkage as needed to
center the water rudder.
❏
2. Move the rudder left and right with the transmitter stick.
Make sure the water rudder responds smoothly and in the
correct direction.
❏
3. Adjust the linkage for a water rudder throw of 1"
[25.4mm]. This can be done by moving the clevis to another
hole on the rudder control horn (external pushrod) or by
adjusting the ATV (internal servo). The amount of throw
should be adjusted as needed for good water handling.
Floats on a model generally add more side area forward of
the CG than aft. This can create a stability problem. This kit
includes a ventral fin that can be installed on the rear of the
fuselage to increase the rearward side area. The Great
Planes J-3 ARF flies well without the ventral fin. However,
there is noticeably less yaw stability.
❏
1. Remove the covering from the slots in the ventral fin
mounting base.
❏
2. Insert the ventral fin in the mounting base. Mark the
fin where it meets the mounting base. Remove the covering
from the fin and mounting base at the marks.
❏
3. Mount the ventral fin base to the bottom rear of the
fuselage with four #4 x 1/2" [12.7mm] screws and four #4
flat washers. Drill 1/16" [1.6mm] pilot holes for the screws.
Enlarge the holes in the mounting base only with a 1/8"
[3.2mm] drill bit. Harden the holes in the fuselage with some
thin CA.
❏
4. Tack glue the ventral fin to the mounting base with
medium CA. Be very careful not to glue the mounting base
to the fuselage.
Install the Ventral Fin
Set the Water Rudder Throw
14
