Rocketry

I’ve decided that I’d like to get my high power rocketry level 1 certification. I do have a LOC IV kit down in the cellar I could slap together and fire off with a small H motor for that purpose. Of course, being me, I just can’t do something that simple. Why follow the KISS principle when you can get overly complex?

With this in mind I’ve decided to start Project Overkill. This rocket with be much stronger than it needs to be. It will be much larger than it needs to be. It will be much heavier than it needs to be. It will be more complex than it needs to be. It will be daunting and intimidating to build, but it will be fun.

The basic idea is simple, three fins and a nose cone. However, the body tube will be four inches in diameter and the rocket will be about six and a half feet tall. It will fly on an H, a small I, or a big I. The H will drive it about 900 feet and the small I will push it up to 1,500 feet. I won’t use the big I for now since I don’t have access to a field big enough.

Since I’m concerned about recovering the rocket within the field I’m going to use a dual deployment system, even though that isn’t strictly needed. I decided I didn’t want to have to go through the hassle of dealing with black powder so I’m using one based on an igniter melting through fishing line similar to this one.

I also plan to fly a video camera in the rocket. I picked up a Muvi video camera similar to this one on sale with that in mind. I haven’t figured out how I’m going to mount it, but I guess I will.

I’ve simulated this rocket in RockSim. It looks like it will fly just fine. When I first simulated it RockSim predicted that it would be heavy enough that the best engine would be an I212, so I ordered one. However, as the parts started to arrive it became clear that the sample parts I had picked from the RockSim database were heavier than the actual parts. For example, I had picked a 60″ parachute and it was listed as 14 ounces. The actual 72″ parachute that I purchased only weighs 6 1/2 ounces. I decided that I should use a smaller engine for the first flight and ordered an H125. Of course, that means that if it survives the first flight, I have a second, larger motor to fly it a second time on the same day.

The current plan is to launch Project Overkill on July 17th at Woodsom Farm Park in Amesbury, MA if it is finished in time. If I don’t finish it in time then I’ll launch it in September (the next HPR launch in Amesbury). I’m not going to stress out and push to finish by July 17th. If I finish by then, great. If not, so be it.

We had a little rocket building party at our place.  Miranda invited two of her friends over and the three of them and Matthew built rockets.  The three girls each built a FlisKits skill level 1 Whatchamacallit.  Matthew built the larger, but still skill level 1, Thing-a-ma-Jig.

[Rockets built by Matthew, Miranda, and Miranda’s friends]

The fins on these kits were interesting. Because of the way they interlock with each other it was very easy to align them properly and we didn’t need any sort of jig to hold them while they dried, though we did use a little tape to hold them together.

Overall the party went well.  Three eight year olds and a three year old are a little bit much for me to handle on my own for a build like this, but my wonderful wife helped out and it was a good afternoon.

We will have the girls over another day to paint the rockets. We’ll bring all the kids to the local hardware store and let them each pick a color. We’ll also take them to a store where they can buy stickers (I’m thinking iParty). When we get back to our home they’ll spray paint the rockets one color each. The morning of the launch they can put on the stickers.