My first ever E launch. 10/16/05

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I got my E15-7W's in the mail Saturday and was dying to try one out, but winds were in the 20 to 30 MPH range. Sunday morning I got up bright and early and headed for the ol' launch area. The wind was still around 10 to 12 MPH when I sent my Estes Big Daddy into the sky with this awsome motor. I have no idea of the peak altitude, but I know it seemed to go about twice as far as it ever had before on a D12-5. This is definitely a calm wind rocket, as weather-cocking is VERY pronounced. The rod was vertical but she arched into the wind immediately after leaving it. Ejection seemed long, but I'm sure it was because of the more horizontal nature of the last half of the flight. The 'chute deployed at fairly high velocity, ripping out one shroud line. It still had a fairly slow descent with no other damage. I can't wait to get my new Thunder Roc clone completed now. I believe it will perform even better on this engine.

[A Fish Named Wallyum]

:mad: What happens when an Estes E9-4 is more like an E9-.5 :eek:
I knew I was in trouble when I saw the shock cord sticking out the side of the rocket. :mad: :mad: :mad:

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:mad: What happens when an Estes E9-4 is more like an E9-.5 :eek:
I knew I was in trouble when I saw the shock cord sticking out the side of the rocket. :mad: :mad: :mad:
Well that just plain sucks.... :mad: Was this built with a baffle in place of the top coupler as you discussed a few months ago? I may build my new one without Kevlar like the last one after seeing this. Heat didn't seem to be an issue because the cord was soooo far from the ejection charge. BTW, I also modified the Big Daddy after this launch with as much shock cord between the parachute and nose cone as there is between the nose cone and body tube, this should eliminate the shred problem, I hope.

[CPMcGraw]

:mad: What happens when an Estes E9-4 is more like an E9-.5 :eek:
I knew I was in trouble when I saw the shock cord sticking out the side of the rocket. :mad: :mad: :mad:

Does anyone else get the same sensation, looking at this picture, as if they just got a paper cut? Or that delayed reaction to when your X-Acto slips while carving toward your thumb?

OUCH!!!

Wonder if reefing the chute lines might have reduced this?

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BTW, I also modified the Big Daddy after this launch with as much shock cord between the parachute and nose cone as there is between the nose cone and body tube, this should eliminate the shred problem, I hope.
(Quoting myself :o ) I launched again today on an AT E15-7W with 3-5 MPH winds. I think it's rod-whip because I'm using a 48" long by 3/16" dia rod and this thing still arced in it's trajectory, though not as bad and not into the wind. (Much better altitude!) It arced toward the side of the launch lug. Recovery deployment was again at a high velocity, but the mod must have worked because the shroud line grommets don't show the least sign of having been stressed!

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Wonder if reefing the chute lines might have reduced this?

New term to me, Craig. This is all I could find on it, but it seems to be close to what you mean: http://www.sailingusa.info/weather_and_reefing.htm#Reefing%20the%20sails Care to elaborate on it for me, please?

[CPMcGraw]

New term to me, Craig. This is all I could find on it, but it seems to be close to what you mean: http://www.sailingusa.info/weather_and_reefing.htm#Reefing%20the%20sails Care to elaborate on it for me, please?

Reefing a chute refers to a means of delaying the canopy from opening immediately, with some sort of mechanical "ring" around the lines up near the canopy itself, which slowly slides down to the common point of attachment as the air fills the canopy to its maximum spread. The ring "regulates" the opening time, and is supposed to reduce the chances of instant-explosive-opening incidents.

[Chas Russell]

For what it is worth, many moons ago, I would sometimes reef a large parachute using a plastic button. Usually a button with four opening through which two of the shroud lines would be threaded. While prepping the 'chute, the button would be pushed up to the canopy. When deployed, the button would slide down the lines and slow the opening of the parachute. Sometimes it would take a few seconds to open fully, while other times it did not really seem to make a difference. Most of the time I was flying competition, so I wanted the parachute to deploy immediately.
I did not do a lot of experimentation with rings or other devices.

Chas

[A Fish Named Wallyum]

Well that just plain sucks.... :mad: Was this built with a baffle in place of the top coupler as you discussed a few months ago? I may build my new one without Kevlar like the last one after seeing this. Heat didn't seem to be an issue because the cord was soooo far from the ejection charge. BTW, I also modified the Big Daddy after this launch with as much shock cord between the parachute and nose cone as there is between the nose cone and body tube, this should eliminate the shred problem, I hope.

Yeah, this was the baffled bird. The problem wasn't the Kevlar, but the half second delay on the Estes E9-4. I think even the elastic would have gutted this bird at the speed it was moving. It was a perfect flight up til then, no matter what RocSim said. :rolleyes:

[JRThro]

Yeah, this was the baffled bird. The problem wasn't the Kevlar, but the half second delay on the Estes E9-4. I think even the elastic would have gutted this bird at the speed it was moving. It was a perfect flight up til then, no matter what RocSim said. :rolleyes:
Bill, I forgot to ask earlier, but did you file a MESS report on that motor? Here's the online form to file electronically: http://nar.org/NARmessform.html

[CPMcGraw]

For what it is worth, many moons ago, I would sometimes reef a large parachute using a plastic button. Usually a button with four opening through which two of the shroud lines would be threaded. While prepping the 'chute, the button would be pushed up to the canopy. When deployed, the button would slide down the lines and slow the opening of the parachute. Sometimes it would take a few seconds to open fully, while other times it did not really seem to make a difference. Most of the time I was flying competition, so I wanted the parachute to deploy immediately.
I did not do a lot of experimentation with rings or other devices.

Chas

I like your method -- it has device-retention built into the function, since the button cannot come off the lines. And I follow your pattern -- two shroud lines per hole, using either six-sided or eight-sided canopies...

Did this method work as well with the smaller 'chutes, like 12" or 14"?

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Reefing a chute refers to a means of delaying the canopy from opening immediately, with some sort of mechanical "ring" around the lines up near the canopy itself, which slowly slides down to the common point of attachment as the air fills the canopy to its maximum spread. The ring "regulates" the opening time, and is supposed to reduce the chances of instant-explosive-opening incidents.

Ah, yes. I've seen video of rocket-ejected safety chutes for small aircraft that use that method of slowing deployment. Just never knew there was a term for it! :D

[A Fish Named Wallyum]

Bill, I forgot to ask earlier, but did you file a MESS report on that motor? Here's the online form to file electronically: http://nar.org/NARmessform.html

Not yet, but I saved the case so that I could. Thanks for the link.

[Tau Zero]

The problem wasn't the Kevlar, but the half second delay on the Estes E9-4. [snip] It was a perfect flight up til then, no matter what RocSim said. :rolleyes:(chuckling) There are *some* things that even RockSim can't foresee.

Remember before I bought RS that I said I didn't think it could simulate our Scram-Jet shock cord separation? :mad: :D ;) I seem to recall that Somewhere in the Bowels of RockSim 7 or 8, you can set the "Chances of Failure," or something to that effect. I'll have to hand it off to somebody else to actually find it, though. :p


Cheers,

--Jay


P.S. *That's* why I couldn't find your post using "Search" -- an alternate "RoxxZimm" :eek: spelling! ;) :D

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(chuckling) There are *some* things that even RockSim can't foresee.

Remember before I bought RS that I said I didn't think it could simulate our Scram-Jet shock cord separation? :mad: :D ;) I seem to recall that Somewhere in the Bowels of RockSim 7 or 8, you can set the "Chances of Failure," or something to that effect. I'll have to hand it off to somebody else to actually find it, though. :p

Well, it did do a pretty good job of predicting a high velocity ejection for the Big Daddy on an E15-7W. Craig ran it through and suggested an E30-7T instead, but I was just half crazy with desire to see a nearly 3 second boost phase.... :rolleyes: :D