Scratch - Interceptor (Downscale) {Scratch} Original Design / Scratch Built

Contributed by Kevin Johnson

Manufacturer: Scratch
(Contributed - by Kevin Johnson - 09/13/04) 74% Estes Interceptor

Brief:
Slightly smaller version of the K-50 Interceptor using the PNC-50SP cone (from the Venom, Argosy, Starhawk, etc.).

Modifications:
I modified the patterns and decals by using PhotoShop to reduce the size of the files to 74%. I printed out the decals on my inkjet printer and then took them to Kinkos to copy onto clear decal paper.

74% Estes Interceptor To build the pods, I made shoulders from the nosecones and glued them into the short sections of 10.5mm tubes. I then used Squadron green putty to fill in the seams, sanded them down and glued on the fins. I used full sized reproduction parts from Molding Oldies as patterns.

74% Estes Interceptor I scribed the panel lines into the PNC-50SP using an X-Acto blade and my Vindicator cone as a reference.

To recreate the exhaust nozzle, I cut 1/2" strips of 1/16" square balsa and glued them around the tail of the body tube. I left the motor mount tube sticking out about 1/2" to make a sort of tailpipe look.

Construction:
About a year ago I purchased a bulk pack of Estes Venom kits to get the nosecones. These cones haven't been made in a while and are the basis for some pretty slick looking kits that I want to clone. Since there were only 6 rockets that used the cones, I had some extras and was thinking that a small Interceptor and Vindicator would be a good use for 2 of them.

74% Estes Interceptor This rocket was made using 13" of BT-50, a standard 18mm motor mount and nose cone from the Venom kit, and the fins and decals were scaled down from the patterns at JimZ's site. I made the wing tip pods from 7/8" of 10.5mm tube from Apogee Components, vacuum formed nose cones from Pratt Hobbies and some carbon fiber fin material. The shock cord is 12" of elastic (using a folded paper mount to the tube) and another 18" of Kevlar®.

Once the patterns were sized and the parts cut, this model went together smoothly. The original was a skill level 3 kit, and since you'd have to custom make some parts and downscale the others, I'd bump this project up to a level 4.

74% Estes Interceptor

Finishing:
I painted the pods banner red and the rest of the rocket flat white before final assembly. After putting the decals on (I had forgotten to print out the page that showed placement, so I guessed and followed my eye on what looked right) I gave the model a nice coat of Testor's semi-gloss clear coat.

Flight:
I cut down a Quest chute from 18" to about 12" because I liked the look of the orange and white stripes. I used an A8-3 for the first flight, which was straight and fast.

74% Estes Interceptor

Recovery:
The ejection came just about at apogee, and the chute brought the model down quickly. A little too quickly as I needed to glue one of the rear cones of the pods back on. I also lost one of the fin tip antennae, but I hear that's pretty common. I got too busy with getting ready for the night launch portion of the launch to do any more flights, but had a B6-4 all set for what I expect to be a wicked high flight. Oh well...this will let me get a slightly larger parachute ready for next month's launch.

Summary:
This was a fun project. It involved a lot of work and a few different skills (scaling the decals and patterns, making decals, scratch building, etc.) and makes for a really cool little rocket.

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