This flying model rocket kit promises a to be a two-stage rocket suited for small fields. Multi-stage rockets usually require a large field as they tend to reach high altitudes. The face card indicates the Firefly will reach 225 feet. Caution : After building the kit and preparing for launch, I found out that the Estes A10-0T rocket engine is no longer being made. Due to this, the Firefly can only be flown as a single stage rocket and not as a two-stage rocket. This Semroc kit is an updated version of the 1968 Centuri Firefly which was marketed as the smallest two-stage rocket. The updated version has a bit more nose weight to increase stability and a studier shock cord setup. The original Firefly used "Shorty" engines. To emulate those engines, mini (13mm) engines are glued into adapter tubes. Four such tubes are included with this flying model rocket kit, enough for two launches.

Additional adapters can be purchased (Semroc part # MC-717). At the time this review was written, the price was $0.80 per package of six. This may be of interest to rocketeers on a budget.

Instructions are clear, well illustrated, and easy-to-follow, this model rocket kit is easy enough to build. Creating a nozzle from a paper shroud is the trickiest part.

Parts List

This Semroc flying model rocket kit is sold in a plastic bag with the cover of the instructions booklet doubling as face card. It shows a color picture of the rocket in flight and promises "Out-of-sight flights".

- 2 body tubes (one long, one short)
- 2 coupler tubes (one with a hole)
- 2 motor tubes
- 2 thrust rings and 4 centering rings
- balsa nose cone with washer weight (5 grams) and screw eye
- 2 sets of 4 laser cut balsa fins
- 4 wood dowels (toothpicks)
- Kevlar and elastic shock cords
- launch lug
- streamer with tape disc
- paper shroud (to be cut out)
- 4 adapter tubes (2 required for each launch)
- water slide decal sheet
- instructions booklet

To build this model rocket, you'll need a pencil, scissors, a ruler, some glue and a hobby knife to remove the pre-cut fins from their balsa sheets. Finishing and launch supplies are also not included with the kit.

Construction

After lightly sanding (and filling) the fins, the booster section is assembled. Start by gluing a thrust ring into the aft (yes, the aft) end of a motor tube. Mark the forward end 7/16" and glue the coupler tube with the hole on it on that mark. Glue the centering rings into place, as per the instructions. Glue the other coupler tube into the short/booster body tube (for say small children).

Mark the booster tube for fin placement and attach the balsa fins. Once the fin assembly is dry, apply glue fillets. Dull the points on the toothpicks and glue them to the booster fin tips. You can skip this step if you feel having pointy items on the fins is unsafe. Form the paper shroud into a nozzle and glue it to the aft end of the booster stage.

Now for the sustainer stage. Tie one end of the Kevlar cord to the other thrust ring and glue it even with one end of the remaining motor tube. Glue the remaining centering rings onto the motor tube. Insert the motor mount assembly into the sustainer body tube. Glue fins and launch lug onto the rocket's sustainer stage. Glue the screw eye (with washer weight) to the nose cone and attach it to one end of the elastic cord. Tie the Kevlar and elastic cords together.

Measurements

The two stage Firefly is only 9" (22.9 cm) tall with a fin span of 4.9" (12.5 cm). The model rocket's body diameter measures .908" (2.3 cm) and, according to the face card, it weighs 1.5 oz (42.6 g).

Finishing

After a coat of gray automotive primer, the rocket was given a coat of Krylon white primer. After sanding the primer, the nose cone was painted dark blue and the other parts were painted with yellow enamel paint (Testors #1214).

The decals for the fins where larger than those shown on the face card, they were almost too large for the fin size of this rocket. I cut a little off the end to make them fit.

Flight Data

This two-stage rocket flies on 1/2A3-4T engines, in single-stage configuration. As mentioned earlier, it can't be flow as a two-stage rocket as the A10-0T booster engines are no longer available.

When it came time to launch this model rocket, recovery wadding was inserted and it hit me that I forgot the motor adapter. Figuring that the metal nose weight would make it stable enough to fly on a C6-3, that motor was tried (sustainer only). Big mistake. The rocket was not stable and wobbled right over to a nearby pond where the ejection charge fired. It landed in the water and could not be recovered.