Model Rocket Competitions

Build/Launch Supplies

Useful tools and materials to have on hand.

• Wood glue. Tite Bond II wood glue is very useful for for rocket assembly. Use CA (cyanoacrylate) glue or other quick setting glue for paper rockets. Paper can wrinkle if a slow drying glue is used.
• Exacto Knife. Useful when cutting balsa wood. Sometimes rocket kits have pre-cut parts, but they will still be attached to the sheet in a few places.
• Exacto Saw. Great for cutting body tubes when building a custom rocket. These are very fine toothed saw blades.
• Scissors. Cutting paper pieces. Shock cord mounts are often made of paper.
• Masking tape. Useful to tightening loosen fitting nose cones as well as helping engines fit in the body tube tighter if you do not have an engine hook.
• Ruler/Tape measure. measuring rocket parts (body tubes, fins). A metal ruler is handy when cutting out fins with an Exacto knife. A metric tape measure can be used to measure rocket lengths of rockets used in super-roc competitions and is part of the scoring.
• Extra Wadding (non-flammable). Some people purchase non-flammable wall insulation to save money because by volume it is cheaper than off-the-shelf wadding.
• Extra igniters. Igniters do fail from time to time. Usually each engine pack, if purchased from WallMart will include one extra igniter and Wadding.
• Elastic thread. Used to help reduce the shock when the recovery device is deployed. It is very handy to combine with kevlar thread when launching egg lofters.
• Spare batteries. Be sure to have an extra set in case your batteries run low and you can no longer ignite the igniter. It is no fun to hike to a safe place to launch and be unable to do so.
• If you plan to build rockets out of other materials, such as paper or transparency film, it is handy to build a cylinder out of used engines. Drill out left over engine material from the spent engine. Slide the engines onto a dowel rod and glue them down. This cylinder can be used to roll the paper rocket and help hold it while you glue it together.
• Modeling Clay. Clay is used sometimes to help add weight to the nose cones and help balance the rocket. It is very handy for trimming rocket gliders to fly better.

Rocket Recovery Methods

Save your fins, use an appropriate recovery method.

• Parachute. A parachute is the most common recovery method used. Common sizes are 9" (inches), 10" 12", 15", 18", 24" and 30". Parachutes are made of plastic, mylar and nylon. Add a swivle to your parachute to keep it from getting twisted up. Mylar parachutes come in many different weights. I use 1/4 mill aluminized polyester parachutes for competitions.
• Streamer. A long piece of material which will slow the rockets fall back to earth, but will not slow it as much as a parachute. I use flagging tape and mylar sheets from the local hobby store to make streamers. Competition rockets use 5" x 60" mylar streamers, depending on the contest and there are minimum width to length requirements.
• Tumble. With tumble recovery, a rocket tumbles back to the earth. You must be careful during launch to make sure the rocket falls clear of objects and people.
• Glide. Rocket, boost and flexi-wing gliders glide back to the ground. A rocket-glider glides back as a single piece. Boost and flexi-wing gliders connect to a launch rocket then separate and the glider glides back and the rocket is often returned with a streamer.
• Helicopter. A helicopter rocket spins to slow down its decent. These are really cool to watch and do not require a parachute. There are lots of different helicopter designs with at a variety of difficulty levels.

Beyond the Basics...Competition

A good way to test your skill and get some recognition.

• Once you have built a few kits, you may realize that rocket building is not too difficult and want to enter local competitions. Members of the National Association of Rocketry can compete in regional and national events. Rocketeers compete in three age groups or as a team. Trophies or ribbons are awarded to winners in each age group, for each competition.
  
  Competition events can be wide ranging. For some events off-the-shelf rockets can be used but for others it is best to build from scratch. Events usually fall into one of a few categories.
• The simplest event is a spot landing competition. A recovery method is chosen for the event then each person tries to get their rocket closest to a target. Sounds easy but it depends on the distance to the target while still having a safe flight. Often competitors use heavy underpowered rockets. Get the timing wrong and you might end up with a 'lawn dart'.
• In a duration event you are trying to keep your rocket aloft the longest. Each launch is timed and recorded. One variation on a duration event is random duration. A contestant puts together a rocket, engine and recovery method to stay aloft only for as long as the chosen duration.
• In altitude events you try to reach the highest altitude. Spotters record the azimuth and elevation then the achieved altitude is calculated. Variations on altitude events include, random altitude where you try to put together a rocket and engine combination to achieve the chosen altitude. There is also a predicted duration event where you get one chance to get closest to the target height.
• Other events judge building ability and include sport scale and future fiction. There is also a plastic model conversion competition where builders make an off the self model, not intended to be flown, into a rocket.
• Super-roc. This competition will fall under the duration or altitude category but requires that the rockets be quite long, given the engine size required to be used. For example, a super-roc rocket using an A engine (13mm) must be between 75 and 150 centimeters long (30 - 60 inches). The picture at the top of the lens is my F Superroc which was just over 13 feet tall. Recently there have been suggestions to cancel this type of event due to the hight occurrence rate of failures. Overall, the point of these competitions is to test your building skills.

Competition Supplies

The tools and materials serious competitors have on hand.

• Fast setting Glue. CA (cyanoacrylate) or other glue used to repair or build rockets quickly. CA comes in different types often labeled Fast, Medium or slow depending on how quickly it dries.
• Slow Setting Glue As mentioned above, Tite Bond II wood glue is useful when more time is needed for construction such as when aligning sections of a multi-section rocket.
• Mylar tape. To reduce weight, do not install the metal clips to hold in engines. Use Mylar tape to hold the end of the engine to the body tube. Also use masking tape around the engine to help it fit tighter in the rocket body. It is like the rocketeer's duct tape!
• Kevlar thread. Used to tie the main rocket body to nose cone.
• Spare parachutes in multiple sizes. Mylar parachutes are preferred for competitions. Nylon chutes are also available in multiple sizes.
• Balsa wood. Use for spare parts or custom builds such as gliders. Hard landings can break rocket fins.
• Digital scale A small scale is useful for weighing your rockets or components. We must fight gravity so strong light weight rockets will often outperform heavier rockets. Egg lofting competitions also have requirements on the weight of the egg used.
• Swivels. Attach to the parachute cord to allow it to untwist if the rocket spins.
• Sanding Sealer. Use sanding sealer on your balsa fins to make them smooth and reduce drag. After the sealer dries use very fine sand paper to smooth the fins.
• Powdered Chalk. Preferrable red or brown to stand out against the background which is blue sky on a nice launch day. Chalk is used by the trackers to track altitude events. Place a good amount of chalk on top of the parachute before putting the nose cone on.
• Highlighters. Many competitors choose not to add weight to their rockets by painting them. Although it is sometimes easier to find a painted rocket than it is to find a brown one. Highlighers can be used to color your rocket.
• Spray paint. Sometimes it is best to make sure it is easy to spot your Helicopter rocket or gliders. Once the judges keeping time loose sight of the rocket, your time is up. The extra visibility may justify the additional weight of the paint. I usually buy orange or red florescent paint which stands out nicely against a blue or cloudy sky.
• Permanent Marker. All competition rockets must include your NAR number on them. Be sure to have a marker with you. It can also be used to add patterns to your rocket rather than paint it.
• Sand Paper. Various grit sizes. Ideally you want your rocket's fins to be shaped like the wing of an aircraft to reduce drag. Sand paper is used to shape rocket fins.
• Fiber Glass sheets. Used to make rocket fins. G-10 is a common size for smaller rockets.
• Spare Balsa Wood Nose Cones. Usually you use a metal eyelet screwed and glued into the nose cone to prevent the nose cone from becoming separated, which may lead to a disqualification. Be sure to have spare nose cones.
• NOMEX or KEVLAR material can be used to protect your recovery system from the ejection charge. If not enough wading is used below the recovery system, a parachute for example, there is a risk of having your parachute get melted by the ejection gases and not fully deploy.
• Baby Powder. Use the powder to keep a parachute from sticking together. Usually needed in humid areas.
• Rubber Bands. Some helicopter rockets use rubber bands to pull up the blades after the ejection charge goes off. Beauty supply stores carry small rubber bands that are needed for most helicopter rockets.
• GPS Unit. If you start launching rockets with larger engines or on high wind days, a GPS unit with a sight-n-go feature can help you find your rocket. For most competition events, you must present you rocket to launch control for inspection following a launch. I use a garmin e-trex Vista.
• Egg Capsule. Either single or dual depending on the contest.
• Piano Wire .020 and .025 Piano wire is used too build competition helicopters and Flexi-Wing gliders. Hobby stores often carry the wire.

Competition Event Tips

• Weight matters so use light weight materials. I have used paper rockets as well as overhead transperency film to build body tubes. Skilled builders also use fiber glass. I have had good success using vellum paper to build rocket body tubes which are very light.
• Flexi-wing gliders. Use the springs from a floppy diskette to hold wood pieces together. Light weight trash bags can be used for the glider. I have used plastic bags from the meat department to build some, but make sure the color is visible so the judges can see your glider. Piano wire is often used to make custom springs for the glider.
• Boost Gliders. Edmonds Aerospace makes many different models of gliders. I have had great results using the Delties made by Edmonds Aerospace. When this event reaches the D motor level, contestants are allowed to use remote controls to test their piloting skills and increase the flight duration.
• Rocket Gliders. A rocket glider contains the engine that was used to launch it, unlike a boost glider which usually separates from the rocket. Edmonds Aerospace makes many different types of rocket gliders.
• Parachute Duration. Be sure to have multiple parachutes handy. Mylar is preferred but there are nice nylon chutes available. Parachute folding is a skill. Never wind your strings around the parachute. Always fold some of the string into the parachute, make another fold and fold in some more string.
• Super-roc. The length is used as a multiplier to give a final score so build long! Some materials are forbidden, like fibre glass rods. I have a picture of a paper super-roc I built out of paper below and it took first place in this category during competition.
• Helicopter: know the Time/Thrust curves of the engines you will use. My son and I recently shredded a couple of helicopter rockets when we used B6-2 engines. The Estes catalog contains the time/thrust charts, keep a copy of this catalog with your launch supplies. Piano wire is often used for constructing hand-built helicopter rockets.
• Do not use the metal engine hooks when building a competition rocket. In competition most people attach the engine to the body tube with mylar tape.
• Launching. Determine if a tower launcher is available for you to use. Adding a launch lug to a rocket adds significant drag, up to 15%, and will decrease performance. Flis Kits often come with a pop lug.
• Plastic Model Conversion. The NAR has a Plastic Model competition event which can be very challenging.
• Piston Launching. Piston launching adds great performance to a rocket. I have not learned this technique just yet but those who use it, get much better altitudes during competition events than those who don't.
• Egg Lofting. Eggs can be quite heavy. Get a good capsule and use some pillow stuffing to protect the egg in case of a rough landing. Pick out your eggs early so you can look for the smaller sized eggs. They should all weigh about the same, but you want to find the small ones. Note that for an Egg loft altitude events the eggs can come down with the parachute and you can use tumble recovery for the body tube. Always check the Pink book and the contest director to verify this procedure. Since the end of the eggs are much stronger than the sides, competitors often cut a hole in the top of the parachute to prevent the eggs from swinging side to side on decent. One bad swing while landing could break an egg.