Great Planes Yak-55M 50-55cc Sport / 3D ARF - GPMA1230 - Manual (Page 8)

8
4-40 Bolt
Ball Swivel
4-40 Nut
4-40 Nut
Brass Bushing
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7. Locate all of the components shown in the picture, a
4-40 x 5 3/4" [146mm] pushrod wire and an additional 4-40 nut.
Examine the diagram that shows the proper way to assemble
the swivel ball link. Mount the swivel ball link into the hole you
drilled in the servo arm.
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8. The photo shows how your pushrod assembly should
look. Center the aileron and the aileron servo. Install the servo
arm onto the servo and the solder clevis into the second most
outer hole of the control horn. Mark where to cut the pushrod
wire. Cut the wire on the mark you made. Remove all of the
components of the pushrod wire from the clevises and the
control horn. Solder the pushrod wire to the solder clevis using
the soldering “Hot Tip” that follows.
How to Solder
1. Use denatured alcohol or other solvent to thoroughly
clean the pushrod. Roughen the end of the pushrod with
coarse sandpaper where it is to be soldered.
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.
❏ ❏
9. After the solder cools, install the pushrod assembly
to the aileron servo and the aileron. Be sure to use thread
locker on the nuts and a silicone clevis keeper on the clevis.