Top Flite FW 190, Instruction Manual

Page: 9 / 36

9
with the hinge line of the aileron. On the aileron, mark
the four mounting holes. Remove the control horn and
drill a 5/64" [2mm] pilot hole at each mark.
Do not
drill completely through the aileron. Attach the
control horn using four #4 x 1/2" sheet metal screws.
Use thin CA to harden the holes.
❏ ❏
3. Install the metal solder clevis in the hole nearest
the end of the control horn. Center the aileron servo
and aileron. Mark the pushrod where it meets the solder
clevis. Remove the pushrod and the solder clevis and
cut the pushrod ¼" [6.4mm]
past the mark. Solder
the solder clevis to the pushrod using the techniques
described in the following
Hot Tip .
HOW TO SOLDER
1. Roughen the end of the pushrod with coarse
sandpaper where it is to be soldered. Use denatured
alcohol or other solvent to thoroughly clean the
pushrod.
2. Apply a few drops of soldering fl ux to the end of
the pushrod, then use a soldering iron or a torch
to heat it. “Tin” the heated area with silver solder
by applying the solder to the end. The heat of the
pushrod should melt the solder – not the fl ame of
the torch or soldering iron – thus allowing the solder
to fl ow. The end of the wire should be coated with
solder all the way around.
3. Place the clevis on the end of the pushrod. Add
another drop of fl ux, then heat and add solder. The
same as before, the heat of the parts being soldered
should melt the solder, thus allowing it to fl ow. Allow
the joint to cool naturally without disturbing. Avoid
excess blobs, but make certain the joint is thoroughly
soldered. The solder should be shiny, not rough. If
necessary, reheat the joint and allow to cool.
4. Immediately after the solder has solidifi ed, but
while it is still hot, use a cloth to quickly wipe off
the fl ux before it hardens.
Important: After the joint
cools, coat the joint with oil to prevent rust. Note: Do
not use the acid fl ux that comes with silver solder for
electrical soldering.
This is what a properly soldered clevis looks like
– shiny solder with good flow, no blobs and flux
removed.
❏ ❏
4. Slide a silicone clevis retainer over the solder
clevis. Reinstall the aileron pushrod with the threaded
clevis attached to the control horn. Adjust the threaded
clevis so that the aileron is centered. Apply a drop of
thread locker to the threads of the pushrod behind the
clevis. Tighten the 4-40 nut against the clevis.
❏ ❏
5. Assemble and connect the fl ap pushrod following
the same procedure. We installed the pushrod in the
outer hole of the control horn and the hole 5/8" [16mm]
from the center of the servo arm.
❏
6. Return to step 1 and install the aileron and fl ap
pushrods on the right wing.