NARAM

billspad wrote:

I have no real sense of what an egglofter weighs but running random numbers in Wrasp it looks like it would have to weigh 85 grams to get that altitude with an E6. Using the same mass and diameter with an E9 yours should have gone 541 meters. So under the best conditions you were mathematically doomed to failure.

The eggs alone weigh more than that. A high-performance egglofter has a exceptionally low Cd, though.

Wednesday was a short day with only one event, F Super Roc Altitude. These models must be at least 2 meters in length. The score is a combination of the length in centimeters, up to 400 cm, and the altitude in meters. This combination of length and power usually yields some entertaining failures. Fortunately, we did not provide any of the entertainment.

Our first model was a pretty sturdy beast. It was constructed from thick-walled 29mm motor tubes fully lined with coupler tube, except for the areas where the motor would go and the last few inches before the nose. It measured just at the maximum length. An AeroTech F25 boosted it to 405 meters, but if we wanted to place, we\'d have to do better.

The second model was made with the lighter Quest T30 tubing and would fly on an Apogee F10, with it\'s 8 second burn. We decided to go with a shorter model to try to get maximum altitude. The model boosted arrow-straight to 904 meters. When the dust settled (and there was a lot of dust in Colorado) it was barely enough to sneak into third place. Had the model been one centimeter shorter, we would have been fourth.

The early shutdown allowed us to get off the range well ahead of the afternoon thunderstorms which were the norm for most of the week.

Thursday was a frustrating day. Gary had built the models for the day\'s two events, D Helicopter Duration and 4xA Cluster Altitude. I would be mainly providing recovery support.

We decided to start with helicopter. Gary\'s models feature internal rotors and tend to boost higher than the normal Rotoroc-style models with external rotors. The timers were having trouble seeing the other high performance models, so we decided to fly our lowest performing model. The booster was one that we had flown several years ago which was BT-55 based with a 24mm mount for D12s. There was only one problem. It was too short for any of the rotor assemblies that we had. Rather than cut the rotors, we extended the tube with a wrap of Kapton.

Since by that time we were approaching the end of the current range crew\'s shift, we decided to wait for the new crew in the hopes that these timers would have better vision. Most new people get assigned to timing duties, since it doesn\'t really require any special knowledge, but it\'s always a crapshoot as to what you\'re going to get. While we were waiting, we decided to start prepping the cluster model.

Gary had worked for hours crafting two pieces of aerodynamic art for the event. However, they were not in the model box! They had been left back at the hotel. The back-up models were there, but not the primary ones. Fran went back to retrieve them.

In the meantime, we flew the helicopter. The model boosted straight out of the tower and at burnout, came apart. The nose had been too loose in the Kapton tube and we fell victim to drag separation. The stress of the high-speed ejection caused one of the rotors to shear off. Although the other two auto-rotated, it was a DQ for separation.

When Fran returned, we got the cluster model ready to fly. It shredded its fins and thrashed about the sky. Another DQ.

We prepped the the second helicopter flight, but by then it was our turn for range duty, so we would have to wait. This time, it worked and turned in a flight of just short of two minutes. While we didn\'t expect that that would be good enough, it ended up in fourth place.

We went with one of our back-up models for the second cluster flight. With time winding down, we took it out to the pad. The daily thunderstorms were closing in and the range was shut down early before we could launch.

Thursday night was the Sport Scale viewing and pick-up. Imagine my surprise when I discovered that the Black Brant was in fourth place after static judging. After the paint fiasco that I had, I had expected it to be much lower. It scored very well in the accuracy, though, which offset the mediocre craftsmanship. I had procrastinated too long to be able to build it so that it could be staged, so there would be no opportunity for mission points. The models behind us all featured missions, so we were unlikely to take a place without a few catastrophes during the flights on Friday.

Bill and I had simmed the model and the launch rod velocity looked marginal on an E15, especially if there was going to be any wind, so I opted for an E30-7 instead. That thing left the tower at warp speed. There was a little bit of coning. The 7 second delay was perfect and the \'chute popped just about at apogee. One of the booster fins came off on landing and another was lost at some other point during the flight, but we were qualified. As expect, we did not hold fourth place.

NARAM-53 will be outside of Cincinnati, Ohio. I\'m hoping for better results next year.

jbuscaglia wrote:

The eggs alone weigh more than that. A high-performance egglofter has a exceptionally low Cd, though.

I forgot the second egg. At 110 grams the numbers work out to exactly what happened. Based on that the only motor that could have won was the E6.

billspad wrote:

I forgot the second egg. At 110 grams the numbers work out to exactly what happened. Based on that the only motor that could have won was the E6.

We knew that it was extremely unlikely to place with the E9. We would have had to have a lot of broken eggsAfter the first DQ, I think Gary was just looking for a qualified flight.

Prior to NARAM, I had thought about the feasibility of staging a C11 to an E9. No idea if that would have worked any better, though.