Lone Star Patriot - L3 build

[jmattingly13]

A while back I built and flew a L3 rocket at Airfest, which had a beautiful launch and landing on an AT M1350. Unfortunately, Kansas happened and after landing, the wind picked up in the chute and proceeded to slam the nose cone into the ground several times, shearing it apart. (It was 3D printed and weighted. Mistake.) Further damage was incurred during a move, and I was not keen on making the complex repairs required.

For my next effort, I decided to go back to something a bit simpler, buying a LOC Patriot kit from Chris' Rocket Supplies, which was also a nod to my L1 cert rocket, a scratch-built Patriot. I will be making some modifications, including glassing the fins and body, and adding nose weight. I'm planning to fly on a Loki 76/6000 (hopefully the M1200 Spitfire--I like noise and light) to around 7000 ft. I will be using this thread to post build pictures and updates, and hopefully good flight data, too.

I'm moderately bad at painting, but I also appreciate a good-looking rocket, so I'll be decking this out in Texas flag livery, a nod to my home for the last four years.

 

[Nytrunner]

Name: Tex-patriot!

 

[jmattingly13]

When fiberglassing rockets, I prefer to use Soller Composites fiberglass sleeve. The glass used here is advertised at 10.3 oz/yd2 before epoxy. I also got some heat shrink tubing to give the airframe a smooth and consistent finish (mostly successful). I've found it also helps squeeze out some excess epoxy. I use US Composites thin epoxy for fiberglass work. They payload section was pretty straightforward.

Next, I assembled the fin can. I used wood glue for fillets and installed the fin can into the booster airframe (minus the aft centering ring). I installed the kit-supplied eye bolt into the forward centering ring, which is not forged or welded shut, so surgery or alternate retention via the motor forward will be necessary. I used wood glue to secure the forward and middle centering rings and fins, then re-enforced the forward and middle centering rings and aft fin tabs (to the motor mount and to the airframe) with epoxy mixed with chopped fiberglass. I then assembled the remainder of the booster airframe using wood glue. A mistake during build led to a large gap at the coupler between the two pieces of booster airframe, so a piece had to be measured and sacrificed from the forward end of the booster airframe to fill the gap. I used the same method to glass the booster airframe from the forward end to the leading edge of the fins.

After applying wood glue external fillets to the fins, I draped 3oz E-glass cloth tip-to-tip in each of the four quadrants of the rocket. Things got a little messier here.

I used 8.7oz E-glass fiberglass tape strips to rebuild the fillets as well as the the leading edges, tips, and trailing edges of the fins. This got even messier.

Now that everything is fiberglassed, the next step is to apply fairing compound to the whole booster section and sand down to profile.