Egg-O-Naut C

[starpug]

I am looking at the Solon parachute. It is really big.
Estimating assuming the bottle holding the egg is 4" dia.:
Inflated dia. = 6'+8"
Assuming perfect hemisphere:
Flat dia. = 10'+6"

Anyone know the actual size?
Was it the largest chute at nats?
What was the biggest parachute posted in this thread?

Thanks to the photographer.
(I think it was Rocketman, but it only credits Dark Sabre so it's ambiguous - could be Dark Sabre or Rocketman or anybody sending it to him?)

From what I saw while they were launching, Solon (which is no los if spelled backward ) had about a 6' diameter chute, it really wasn't that big.

The largest one that I recall was New Trier, I think it was a little larger than Solon's, so somewhere in the 7-8' range.

I can't believe I had a bigger parachute then Solon :/

[mosloudo]

Too late now but,
Anybody tried a dethermalizer?
http://www.apogeerockets.com/education/ ... tter04.pdf
I just skimmed the article, I think I get how it works: rubber bands slowly pull something through silly putty, and then once it pulls through, a catch is released, letting go of some of the lines to the parachute so it collapses, effectively turning it into a streamer.

By using a dethermalizer on practice launches, the egg holding section may be prevented from drifting too far away.

[rocketman1555]

It seems like that would be more effective for model rockets, I'm not sure how well it would work for water rockets, or if it is necessary. You can always wrap a rubber band around the parachute lines so that it will act as a streamer all the way down, but you can still see if it deploys or not.

[mosloudo]

Yes, that could work, but then, stopping the parachute from opening fully on purpose also prevents you from discovering some problems that could interfere with full deployment of the parachute when intended.

And the dethermalizer plan in the article seems difficult because it's miniaturized - but if you don't need to make it so small, it could be easier to build and use. When used in place of an egg on practice launches, the dethermalizer unit just has to be the same or smaller size and mass than an egg, and the difference made up by adding weight.

[calgoddard]

In response to the post above, 40 seconds for a SciOly backslider flight duration is extremely unlikely. Troy's first place time at the SoCal State finals in 2004 was 27 seconds. It was a perfect design and a perfect flight under ideal conditions. I have witnessed hundreds of SciOly backslider launches and have never seen a flight longer than Troy's gold medal flight, even at Nationals in 2005. I am talking about Troy HS of Fullerton, California, and that high school has been the National overall champion seven times as I recall.

I don't want students to be disappointed if they don't get 40 second backslider flights. Any flight time over 15 seconds was typically very competitive for a 1L or 2L backslider bottle rocket.

Before the Egg - O - Naut event, when parachutes were allowed in the Bottle Rocket event, the rules required that the entire rocket be recovered with the parachute to obtain max points. Times above 40 seconds in the old Bottle Rocket event were extremely rare, even at the most competitive competitions. This was true even though the old Bottle Rocket event did not require the launch and recovery of an egg. A complete 2L bottle rocket weighs much more than an "egg capsule" under the Egg - O - Naut rules.

Any flight time over 20 seconds was competitive in the old Bottle Rocket event when parachutes were allowed. Don't start thinking you are a failure if you are not getting one minute flight times if the 2011 Bottle Rocket event rules are similar to the old Bottle Rocket event rules that allowed a parachute. Such a flight would require a lucky encounter with a major thermal. I recall that Troy (CA) got over one minute at Nationals in the late 90's.

I have no connection with Troy HS (CA) but have great respect for its SciOly program and its students.

[amerikestrel]

I have a (probably very stupid) bottle rocket question.

I purchased this launcher and this pump, but I can't figure out for the life of me how to attach the pump nozzle to the tube in the launcher so that pressurizes the rocket. What am I doing wrong?

[rocketman1555]

There should be an adaptor with the launcher if the pump doesn't work. Although it should work fine, I have the same launcher, and just bought a bike pump and it works fine, just make sure you latch the pump so that it seals with the tube from the launcher, that may be the issue.

[fleet130]

See: PITSCO Website Click on the small thumbnails below the picture. The 5th (depending on which photo you're looking at) photo shows the launcher hose being inserted into the pump hose chuck.

There is a release lever on the chuck. Lift the lever as shown in the picture to open the chuck. Push and hold the launcher hose end fitting firmly into the chuck. Fold the lever back down to lock the hose fitting in the chuck. Lift the lever again to release the launcher hose from the chuck.