This model actually began as a last minute sport scale project for a local DART (NAR Section# 317)contest sometime around 1987. Dave Cook (our section advisor) had a NARTS scale pack for the Viper Sounding Rocket and due to it's fairly straight forward design we figured it was a good candidate for a 2-day sport scale build.
Twenty four years later about all I had left were the fins (which were cut from 1/32" plywood) and the painted plastic nosecone which was probably "borrowed" from some kit that I've long since forgotten. By far the biggest challenge was locating the scale data we were using as a reference. After much searching, one of DART's original San Diego members, Jeff Brewer, located an old copy of our section newsletter "WARP-9" in which we had done a write up for the Viper and included a copy of the original NARTS drawings.
I decided that the original fins I had cut were not exactly to scale and decided to recut them using the data from the drawing. Again I chose to use 1/32" plywood as we had done on the previous model. While 1/32" doesn't provide much surface area for the fin joint, the reinforcing gussets will make up for most of that.
Like almost every other model I build, I used the diluted Elmers wood putty for filling the grain. Of course filling the grain in aircraft grade plywood is much easier than filling balsa grain, so this step went fairly quickly.
For the airframe, since I was not rushed like I was the first time, I decided to try and achieve a more scale-like appearance. As can be seen in the drawing, there are 5 sections to the rocket (starting at the bottom):
1. Empennage (Fin Assembly)
2. Main Airframe
3. Payload Coupler
4. Payload
5. Nose Cap and Tip
The first step was to glue the correct length of tube to the nose cone to represent the payload and fill the joint so as to make it appear like a single unit. I then cut a small section of tube to represent the payload coupler and glued a balsa bulkhead to bottom of that which becomes the tube break point for recovery deployment.
The fins were attached with standard CA glue. Some VERY small fillets were applied for strength.
Next, the airframe below the payload coupler was painted white with the fins and fin can painted silver.
The nose cone was painted to represent its three components:
1. Payload (Aluminum)
2. Nose Cap (Magnesium)
3. Nose Tip (Steel)
The Nose Cap and Nose Tip were painted using testors "Metalizer" paints to give a more realistic metallic finish.
The final step was to add the fin cuffs and gussets. I had Gordon at Excelsior Decals make me up some appropriately sized rivet decals. These were made of steel on the prototype, but the testors steel I was using didn't contrast with the aluminum as much as I'd hoped. In the end the overall appearance was far superior to the first model we so hastily threw together that night in Dave Cooks garage.
On a personal nostalgic note, by using the nose cone from the original 1987 model, I feel I was able to preserve a small piece of my own spacemodeling past with this rocket. A past filled with great memories of all night build sessions with my best friends and 80s rock blasting from the boom-box. I can almost smell the Pizza!
