26
and matched will become obvious to you.
When you've got everything just right,
rotate the control surface a little to make sure you
don't have something binding (you won't).
Then, with everything clamped in position,
using a very sharp pencil (a fine lead mechanical
drafting pencil works well), mark around each
hinge piece on the aileron/flap spar so, when you
remove them, you can just line them back up and
use the hinge itself as a drill guide.
LocTite the rod end bearings into the hinge
tube mounts and recheck all alignments before it
has time to set up. Then, after it has set up, remove
the hinge tube mounts and drill them for the rivets.
Drill all the way through the aileron hinge tube and
bearing shank and out the other side. Do your best
to keep the holes centered on the hinge tube as you
go in. On the other side, it'll more or less center
itself automatically as the bit looks for the low
place on the inside of the tube.
You can now put the rivets in the
bearing/hinges. You can also clamp each hinge in
its position on the aileron spar, as indicated by the
pencil marks, and match-drill the holes. Then put
the nut plates on the back side.
You have a little more rivet work to perma-
nently attach the gussets. Again, refer to the plans
to check that everything is finished as shown.
When all the above is done, you can remove
the flaps and ailerons, if you desire, and put them
some place for safe keeping until they are needed to
compete the control system actuation system.
Finishing the Ailerons
At this point there are a number of
aileron/flap details that have yet to be completed,
but will be in due time. They are:
- Pouring lead in the aileron balance tubes
- Final riveting the trailing edges
Balancing the Ailerons
This can be done at any time after the
ailerons are hinged to the wings.
To balance the ailerons we’re going to pop
rivet or sheet metal screw a 3/4” O.D., thin wall
aluminum tube that we’ve filled with lead inside
the leading edge of the aileron. The hole is clearly
visible in the ailerons, but you’ll have to go down
to the hardware store and buy a piece of aluminum
tubing. You’ll want to put 5 pounds, 4 ounces of
lead in that tube. It’ll hold a little over 6.0 pounds
if it is poured solidly full of lead (drill out some to
balance it) and just over 5.0 pounds, if other meth-
ods are used.
Although you can go through an entire bal-
ancing process in which you suspend the aileron by
thread and estimate the fabric and paint weight and
then determine how much lead you’ll need (see
Russ Erb’s CD), the range will always be between
five pounds and five pounds, four ounces. Since
overbalancing is better than under balancing, use
five pounds four ounces as the target.
Pouring Lead
Go to the fuselage section where you bal-
anced the elevators and all the same caveats and
procedures apply: use a face shield and respirator,
do it out doors, wear welding gloves and make sure
no moisture is present as it will turn to steam and
blow molten lead all around.
Stand the tube up and either make a wood
The aileron cove cover can be installed at the same time the
skins are fastened down. The rivets in the pocket area are
stainless steel pop rivets.
Inside forward view of an aileron nose: note the balance tube
at the very forward part of the aileron. This area is closed up
on kit ailerons so you can
’
t see the tube.
Summary of Contents for Bearhawk N33RB
Page 1: ......