Modular rockeTs Building Baffles - National Association of Rocketry

ocketIn 2007 I built a modular rocket(inspired by the article in the Sept/Oct2006 Sport Rocketry) for a 4-H aerospaceproject. A modular rocket is notconstructed in the same way as a regularrocket. A modular rocket is assembledwith nuts, bolts, and screws, rather thanglue. This allows the rocket to be disassembledfor maintenance and repair. Inaddition, a modular rocket can be reconfiguredto accomplish other missions and can be upgraded with new technology at anytime. This article will describe how I constructed this rocket and provide information foranyone else interested in building such a rocket.I will discuss two different types of modular rockets: fully modular and semi-modular.A fully modular rocket can be completely disassembled. A semi-modular rocket allowscertain parts to be removed such as the fins or motor mount. This concept is useful forrockets that need to be easily transported or repaired, but do not need the versatility of afully modular rocket.I will start by discussing the modular rocket that I built for my 4-H project in 2007.The first step was the design phase. I designed the rocket with RockSim and made handdrawings of the internal components. Keep in mind that almost any rocket can be mademodular as long as the body diameter is large enough to house all of the internal components.I designed this rocket with two main goals in mind: make the entire rocket modular(i.e., no parts would be glued together), and build the entire rocket from scratch.The tail section internal assembly is the most complicated part of this rocket. Thisincludes removable fins, removable motor mount, removable centering rings, an ejectionbaffle, and an inverted coupler. Figure 1 shows the internal assembly of the tail section. Irolled the motor mount tube with five wraps of two-ounce fiberglass. The fins and centermodularby Caleb Boe NAR 83769Caleb Boe and his completedmodular rocket.20 MAY/JUNE 2010 Sport Rocketry