GO GO GODZILLA

by Dennis McClain-Furmanski

“Oh no, they say he's got to go, Go Go Godzilla.” - Blue Oyster Cult

This rocket started life as a rubber Godzilla head from a drinking cup souvenir I got at the first run of the 1998 remake of the classic monster movie. I noticed that the screw-on cap very almost perfectly on an Estes BT70 body tube. From them on, it was as inevitable as a SciFi Channel re-run.

Parts:

• 4" x 24" x 3/32" basswood (preferably warped)
• 4" x 12" x 3/32" basswood (not warped)
• 11" of BT70 body tube
• 4" BT70 coupler
• Rubber Godzilla head
• 4" of 5/16" styrene tube (launch lug)
• 1" of PML 4" Quantum tube
• 4" of 24mm motor tube
• 3.75" (E size) motor hook
• 2 CR-5070 centering rings (24mm BT50 in BT70)
• 6' heavy Kevlar cord
• 6' 1/8" elastic shock cord
• Devcon 5 minute epoxy used throughout. Finished size: 17" tall, 8" maximum span (tail tip to ring), weight 9 ounces.
• FIN PATTERNS

Construction:

The coupler was glued into the screw cap in the bottom of the head with plenty of epoxy fillet inside. The Kevlar cord was cut in half, and both halves tied into a loop with a knot at the matched ends. The loops were tripled by wrapping and knotted in the center, leaving a triple loop on each end. One end on each was tied into several more knots. One of these was then epoxied by the knotted end into the inside of the coupler tube, in the manner of an LOC/Precision shock cord anchor. The other was epoxied in the same way inside the body tube, at its inside midpoint.

The motor mount was constructed by inserting one end of the motor hook through the 24mm tube, ½" from one end (forward) and hanging over the other end (aft) by ¼", and taping in place. One centering ring was slid over the forward end and down over the forward end of the motor hook and epoxied with fillets on both sides. A ½" long by ¼" wide notch was cut on the inside edge of the other ring, and slid over the aft end of the tube, with the notch aligned with the hook and epoxied ½" forward of the aft end of the motor tube. This ring was also epoxied with fillets on both sides. Once dry, epoxy was spread inside the body tube and the motor mount inserted and glued in place, with the aft end of the motor tube even with the aft end of the body. Fillets were added to the top for the forward ring through the forward end of the body, and to the aft ring.

The tail was cut (see patterns for all cuts) from straight basswood and glued on the body with the bottom of the tail even with the aft end of the body. The legs were cut from warped basswood, with the pattern reversed on the second cut, so that the legs had opposite curvature. The back sides of the legs were then glued by the surface (i.e. not the edge) to the body, so that the curvature made the toes point more directly opposite from the way the tail pointed.

The ring of Quantum tube was then glued to the back sides of the feet and through the notches in the feet. Small strips of basswood were cut and placed at these contact points for reinforcement, and ample fillets added. Fillets were also added on the inside and outside body/leg joints. The launch lug was epoxied against the body/tail joint, and fillets added to the tail/body/lug joints. See the bottom view for detail of leg/ring placement.

The shock cord was tied into a loop and tied to the Kevlar loops inside the body and the “head" coupler. Finally, a notch for the launch rod was cut in the back side of the head where the edge hung over the body. This is to be aligned with the launch lug for launching.

Finishing:

The body section was primed with white appliance epoxy paint. Silver and black were sprayed in splotches across the legs, tail and body, except on the stomach (left white). No filler was used on the basswood, so that it would have a rough texture.

Flight:

An 18" Top Flight X-form chute was attached to the Kevlar loop in the head. Two flights were made on Estes E9-6 motors. Both flights arced very slightly to the tail side, with no spinning. Ejection was just past apogee at approximately 600'. Ejection and descent went fine. On the second landing, it hit a rock and cracked the left foot away from the leg, but the Quantum ring held it in place. This was easily repaired with CyA.