USMRSC Rule 27: Dual Egg Lofting Altitude Competition (DEL)
This primer presents, in one place, all the information you need to succeed in NAR model rocket competition in this event.
TCC has provided a link to the official rules whenever we discuss a rule.
Your entry must:
* Be a model rocket as described by the United States Model Rocket Sporting Code. USMRSC 3.1-3.9
* Use NAR Contest Approved motors: http://www.nar.org/SandT/pdf/CombinedMotorsByImpulse.pdf USMRSC 4.1, 4.4
* NOT eject its motor casing(s) without a recovery system. USMRSC 9.2
* Have your NAR number or your name on the outside, large and clear enough that the contest officials can easily read it. Teams must use the Team number or name. USMRSC 9.4
* Have been constructed by yourself or by one or more members of your Team. You may not enter Ready-To-Fly rockets (no construction required) in NAR sanctioned competition. USMRSC 9.9
Know the rules
Your having a grasp of the bigger picture can increase your enjoyment of NAR competition. You can read the Pink Book Lite to see only the rules for competitors, not for Contest Directors or other contest officials. Read the full USMRSC (Pink Book) to see all the rules.
* Pink Book Lite: http://ojames3.tripod.com/tccnarcontesttips/USMRSCLight.html
* Full USMRSC: http://www.nar.org/pinkbook/
General Competition Tips:
Contest Etiquette by Kevin Paul Wickart, NAR 59720, cr 1998, the author
Beginning Competition -- The RSVP Principle by Kevin Paul Wickart, NAR 59720, cr 1998, the author
Guide to NAR Contest Rocketry Information for Beginners by Jeff Vincent, NAR 27910, Northeast Regional Contest Chair,
Which are the Main USMRSC Rules for This Event?
What is the Goal?
The goal of this competition is to achieve the highest flight while carrying two Grade A Large hen’s eggs and return the eggs unbroken.
Are There Any Special Considerations?
* DEL is divided into classes based on the total impulse of the motor(s) you must use. USMRSC 27.4
* No one may catch the model as it descends. It must be allowed to strike the ground. USMRSC 16.7
* After the flight, you must present the model, unopened, to the contest officials and only remove the egg in the presence of the contest officials. USMRSC 27.3
* A Contest Official will provide the egg. USMRSC 27.2
* Each egg will weigh between 57 and 63 grams and not be more than 45 millimeters in diameter. USMRSC 27.1
* Nothing (tape, glue, etc) can be affixed to the egg. USMRSC 27.1
* Your entry can be staged and/or clustered as USMRSC 27 does not specify otherwise.
* Rule 10.4 does not apply. YOU MUST RETURN YOUR ENTRY.
Do I Have to Return the Model to Place?
How Many Flights Can I Make?
* You can make up to two flights. USMRSC 10.1
* You can use more than one model. USMRSC 9.7
How is the Competition Scored?
Your official score is the highest single altitude achieved by your entry on up to two official flights. USMRSC 27.1
What Will Disqualify My Entry?
Your entry will be disqualified if:
* Either egg is broken or you break an egg while removing it from your entry USMRSC 27.3
* You cannot return the model. USMRSC 27.5
* You open the model without a contest official present. USMRSC 27.3
* If it is unsafe in operation USMRSC 11.1, 11.2
How About Some Suggestions for New Competitors?
Dual Egg Lofting Altitude Competition (DEL) is different from Altitude Competition (ALT) in that you have to have a model designed to safely hold two Grade A Large hen’s eggs.
Hen’s eggs are more durable than most folks think they are as long as they are vertical. You don’t need thick padding. I use the foam filter for a room air conditioner. I use two or three layers on the top and bottom and one layer around the egg if it fits in the capsule. The trick is to keep the egg from hitting on the side. After all, that’s how you break one for breakfast, isn’t it? Any of the capsules from the kits and/or vendors above, with a little padding, will adequately protect your egg.
In C DEL, your entry should weigh less than 2 ounces empty. The Quest Courier and Estes Eggscaliber are too heavy for C DEL.
You may find these egg lofters at your local hobby store. They can be modified for C and D DEL by adding an extension between the upper and lower halves of the egg capsule and a bulkhead between the eggs:
For C DEL – Custom Elite http://www.hobbymasters.com/customelitemodelrocketkit.aspx
For D DEL (with 24mm motor mount) – Quest Courier http://www.questaerospace.com/itemdesc.asp?ic=2011&eq=&Tp=
For D and E DEL – Estes Eggscaliber http://www.estesrockets.com/rockets.php?pid=002123
You can make the extension from commercial model rocket tubing or an old paper towel roll. If the tubing you select is smaller in diameter than the halves of the egg capsule, you can expand it. Slit its side along its vertical axis, spread it open to the right diameter and insert strip to fill the gap. If you need to make it smaller, simply slit the tube and overlap the sides of the split. In either case, you will have to provide a solid bulkhead between the upper and lower eggs to prevent the upper egg from breaking the lower egg during boost.
Some of the vendors on the TCC Competition Vendor list offer egg capsules and/or advanced egg lofting kits.
The trackers must be able to see your model to be able to track it to apogee. Because egg lofters are usually larger and slower than other altitude competition models, trackers tend to have fewer problems with egg lofters than any other altitude competition. You can increase your probability of getting a good track by using “tracking powder”. Tracking powder is colored powdered chalk or dry Tempra paint that you pack in your rocket so that it is ejected with the recovery system. You can buy chalk for a carpenter’s chalk line at almost any hardware store. Chose a color that contrasts with the cloud/sky conditions you expect to encounter. Red works well in most conditions. Don’t use blue unless white clouds cover the sky. When you pack your recovery system, leave some space at the top for the powder. Tracking powder is messy. You can simply pour the powder in or wrap the powder in a small piece of recovery wadding to minimize the mess. Powder adds weight. Experiment before the contest to determine the minimum amount you can use and still get a noticeable cloud of powder at ejection. For example, for B ALT (about 1000 feet), using a ¾ inch body tube, use enough powder to fill the tube for ¾ inch (one caliber). This will be about 0.1 ounce of carpenter’s chalk.
Two eggs will stress your recovery system. Here’s some good info on building/selecting and packing competition parachutes:
Many vendors have competition models and/or competition supplies:
What Else & What Next?
What Type of Fins Shape is Best by Tim Van Milligan:
Design, Construction, and Flying Strategies for Achieving Maximum Altitudes by Tim Van Milligan
Take No Prisoners Tracking Powder
Good info on building/selecting and packing competition parachutes:
Piston Launching for Egg Lofters – the Hot Ticket!
Simple Tower: by Bob Supak, NAR 65523
Take 3 1/4" aluminum rods, each about 24" long. Depending on what size model you want to launch, take an 18" piece of same body tube and put a few wraps of tape at each end. Place the 3 rods in a triangle around the body tube and secure with rubber bands, leaving 6" of the ends of the rods exposed. Now place the rods into a coffee can full of wet cement or plaster and let set. Voila - launch tower
Piston Launchers Explained – Apogee Components:
Floating Head Piston Launcher – The Odd Couple Team T-085, Jeff Vincent NAR 27910 and Chuck Weiss NAR 35775:
NAR Competition Plans http://www.nar.org/competition/plans/eggloft.html
Tim Van Milligan, Apogee Components http://www.apogeerockets.com/education/downloads/Newsletter247.pdf
TCC NAR Competition Bibliography
Yahoo group for discussing model rocket competition:
Use computer simulations to determine altitude and sink rate for various rocket/motor/parachute combinations.
* Free altitude simulations:
wRASP - http://www.wrasp.com/
* Free sink rate simulation:
George Gassaway’s NARAM Competition Tips
US Spacemodeling (International Competition Tips):
US Spacemodeling Home Page (International Competition):
rmr Frequently Asked Questions – Part 9: Competition and Records: