AIM-9/2 Sidewinder!
1/2 SemiScale H Powered AIM-9 Sidewinder High
Powered Rocket Project
Construction
Note: The following is written in past tense but construction
has not yet started at the time of this writing. However, the parts have
been ordered.
Fuselage
The fuselage of the payload section was cut from Rocket R&D 2.6"
x 34" tubing. The nose section was constructed from a 4 3/4" section
of tube attached to an Estes NC-80B nose cone. The aft section was made
from an 11 1/4" long section of 2.6" tubing. An Rocket R&D 2.6"
payload coupler and shock chord mount was epoxied to this. The payload
coupler also serves as the aft payload bulkhead.
The fuselage of the motor section uses, per design, a single
piece of Rocket R&D 2.6" x 34" tubing. A 1/2"
section of coupler tubing was inserted about 2/3 the way from the end to
form the forward motor section bulkhead. Four slits, 13" long were
made in the aft end of the tube for the fins and fin attachment flanges.
The fin attachment flanges were cut 1/2" wide and 12" long from
3/32" premium aircraft grade birch plywood and epoxied to the body
tube on each side of the slits. 2 oz. fiberglass was added as fillets to
these to provide additional strength. The motor section retaining ring was
made from a section of 2.6" tubing with a slit in the circumference
to allow it to fit over the 2.6" fuselage tubing.
Motor Section
The motor section is built around a 20" piece of Rocket R&D
1.52" tubing. The centering rings (Rocket R&D 1/8 plywood) were
epoxied to the motor tube at the appropriate locations. Then the fin attachment
flanges were epoxied to the motor tube and the aft centering rings. The
fin attachment flanges were cut 1/2" wide and 12" long from 3/32"
premium aircraft grade birch plywood - the same size as the fin attachment
flanges used on the fuselage to simplify construction. An alignment template
made from a spare piece of wood and 3/32 inserts (to temporarily take the
place of the rear fins) was use to keep the attachment flanges aligned
while the glue cured. 1/2" holes were cut in the forward end of the
motor tube for ejection gas escape and the end of the tube plugged with
a 1/4 plywood circle. This was then reinforced by adding a layer for 2oz
fiberglass across the top and down the sides of the tube. An eye bolt was
then inserted into this for attachment of the parachute. The motor section
was completed by attaching four small L-brackets to the aft centering ring
to provide additional retention.
With the motor section structure mostly complete, the rear fins were
mounted. The fins were cut from 6"x12" 3/32" premium aircraft
grade birch plywood by simply removing a 5"x5" corner. The fins
were then inserted into the motor section fin attachment flanges and holes
drilled for the 5 bolts that retain each fin. 1/2" 6-32 bolts
and blind nuts were used to attach the fins. The motor section assembly
was then inserted into the motor section fuselage and holes drilled in the
fuselage fin attachment flanges for the 4 bolts that attach the fins to
the fuselage.
Payload Section
The payload section is built around a frame constructed of Rocket R&D 1/8"
plywood centering rings and 1/4"x1/2" spruce stringers. The centering
rings were notched and the stringers epoxied into place.
The front fins were cut from 3/32" premium aircraft grade birch
plywood with 1/8" wheel collars epoxied to their pivot points. The
wheel collars are used to attach the fins to the 1/8" music wire axles
that are mounted on nylon bearings on the second bulkhead of the payload
section frame. The axles have servo arm mounted on them and are connected
to pushrods for future guidance controls. In the initial versions the pushrods
are anchored to the payload section frame.
Contruction of the payload section was completed by installing the
fuselage attachment bolts. The payload section was inserted into the aft
payload section fuselage and holes drilled for the 8 1/2" 6-32 bolts
and blind nuts. Once the aft section was secured, the nose section was
inserted and hole drilled for the 41/2" 6-32 bolts and blind nuts
used to retain the nose section.
