I'm basing my C engine Egg Lofter design on the old Competition Model Rockets Robin design.
To see the CMR catalog: CLICK HERE
I'm really doing a lot of guessing with my competition designs. I know you have to keep them light and aerodynamic.
The only NAR competition I did was in 1975 and 1976. Over the years some things have changed, other elements haven't really changed at all.
I'll base my model height and body tube diameter on the Robin design. Note the CMR tube walls were a little thinner than the equivalent Estes sized tubing. I'll be using Estes tubes in these builds.
The model itself is very simple except for the Egg Capsule.
Years ago, CMR was the main source for lightweight, vacu-form nose cones. CMR also made the larger egg carrying capsules.
Apogee now sells vacu-form capsules. This parts pack has shoulders for both 18mm and 25mm models.
This build is one I put together for the recent NARAM. After a two hour tour of Estes, I got back to the launch field too late to fly it!
Hi, Chris,
ReplyDeleteThe Robin is a cool egglofter. I built one back in the day from a genuine CMR kit. Ended up destroying the egg capsule on an ill fated flight. I flew the rocket several more times after fitting it with a regular CMR vacu-formed parabolic nose. Even flew it as a two stager using a booster from an Estes DOM bird, the Sky High. Are you still planning on flying your Robin with an egg for a sport flight?
Hi Ed,
DeleteI remember the Sky High design. I liked how all the fins lined up, no breaks between stages.
I probably will launch the egg lofter for a sport flight.