Rocketry on TV!!

[troj]

Originally posted by slim_t
Well, it was LDRS. Was it EX day?

No, as they were commercial motors, and therefore could NOT be flown on EX day.

Probably not, but I'm sure they took the proper safety measures. Obviously they did or that thing would have caused some damage.

It flew from pads much further away than a typical two-M cluster would fly from, for safety reasons. More "out there" projects should ALWAYS utilize extra offset distances, as a safety precuation.

I mean, they tried to hold the chutes in with masking tape. I'm not even into high power, but I knew enough to predict what was going to happen on that flight.

The masking tape had nothing to do with the early deployment, and with the way the parachute compartments were built, it was fine. The parachutes came out early because the electronics detected apogee early due to some design problems.

Don't condemn a design that you're not familiar with. The porta potty was structurally sound, and the way the parachutes were held in was fine. There were some other issues which caused the problem.

 

[karatekicker271]

I agree, don't condem it. Now if this thread doesn't turn around, mods would you please delete the thrad. Some of you guys are acting a little childish... You can't change the fact that it flew

 

[karatekicker271]

Also, about the K going through the wall at the hotel... We were discussing this thread at ny clubs rocket launch, and our Prefect as well as 2 or 3 members who were at thst LDRS said that that never happened. +f that had happened, do you think tthe hotel would have a "rocketry discount" or even allow rocketeers in their hotel?

 

[troj]

Originally posted by karatekicker271
Also, about the K going through the wall at the hotel... We were discussing this thread at ny clubs rocket launch, and our Prefect as well as 2 or 3 members who were at thst LDRS said that that never happened. +f that had happened, do you think tthe hotel would have a "rocketry discount" or even allow rocketeers in their hotel?

It was an I motor, I don't think it was Orangeberg, and a motor really did ignite in the room. The guy installed his igniter in the hotel (not supposed to do that) and was doing a continuity test on the igniter, heard the pop and knew what was about to happen. He grabbed the rocket and hung on until the motor burned out.

He then went down to the front desk, told the manager what happened, and said he'd pay for any cleaning the room required.

 

[cjl]

There is a BIG difference between an I motor going off in the middle of the room, and a K motor going through 3 walls. That story sounds more believeable (although I have never seen an ignitor pop from a continuity test)

 

[jraice]

Well someone talked about the M motor possibly breaking free and killing someone. A few years ago, mabye two, a large white rocket flew on what I believe were 4 L850's. Well at about 1000' the centering rings broke loose, it was like a mushroom cloud, it was my first high power launch and I thought it catoed, as the parts began to fall 5 feet away from me I heard a loud CRASH, one car down the line one of the casings went through the back window, broke through the chair, out the front window, and into the mud. I heard a loud roar and it seemed like the motor was still under thrust, if it wasnt well it had a lot of speed. If someone was in there they would be dead, for sure. I also saw a picture of a rocket that went through the front window, lawndarted, and landed on the drivers seat, they said there was a mother in the front passenger seat, and a young girl in the back, now the L motor hit the car fast but that rocket didnt lawn dart in 3 seconds, that lady should have been out of the car when they yelled heads up. She may have heard it and though, oh well the car is plenty safe, these two stories definetly prove that theory wrong....

 

[artu]

Originally posted by troj
It was an I motor, I don't think it was Orangeberg, and a motor really did ignite in the room. The guy installed his igniter in the hotel (not supposed to do that) and was doing a continuity test on the igniter, heard the pop and knew what was about to happen. He grabbed the rocket and hung on until the motor burned out.

He then went down to the front desk, told the manager what happened, and said he'd pay for any cleaning the room required.

Hi kev, this was the famous I-65 at Danville Dare, it was held on to and out the window for the smoke to get out of the room.

It cost him $500 for cleaning up the room and th broken window.

I was watching it from the super 8, it happened in the comfort inn.

It is super amazing the old wives tales this turns into, even back in the day on "Compuserver ModelNet" the wives tales were3 turned in less then 24 hours.

 

[slim_t]

Originally posted by troj
Don't condemn a design that you're not familiar with.

Well I wasn't condemning the design itself, just the use of masking tape to hold in the chutes. In fact, I believe, unlike others, that the rocket was in fact stable, and would have flown perfectly if not for the early ejection.
Even if it was an electronics failure, or whatever else, I still think the chutes should have been more secure. Even without the ejection charge, I bet the flight would have produced sufficient pressure to blow the chutes, considering the flex of the potty walls, and the chutes being mounted in a horizontal tube. I just didn't see why they would go through the trouble to build such a rocket and then skimp on the recovery system. But I'm not trying to argue with you. For all I know, you built the thing, and know all of its details. But I would like to know how you know the electronics failed and the charge blew early.

Karatekicker, I appologize to you for this post. I wasn't going to reply, but then I figured it might be ok since you replied to the motor through the wall posts.
If you or the mods feel this was out of line, please delete it, or ask me to, and I will delete it myself.

I mean no anomosity in any of my posts, so please don't read any into it.

Tim

 

[troj]

Originally posted by artu
Hi kev, this was the famous I-65 at Danville Dare, it was held on to and out the window for the smoke to get out of the room.

It cost him $500 for cleaning up the room and th broken window.

The important thing is that the guy did the right thing and paid for the cleaning.

I was watching it from the super 8, it happened in the comfort inn.

It is super amazing the old wives tales this turns into, even back in the day on "Compuserver ModelNet" the wives tales were3 turned in less then 24 hours.

No doubt!

-Kevin

 

[troj]

Originally posted by slim_t
Even if it was an electronics failure, or whatever else, I still think the chutes should have been more secure. Even without the ejection charge, I bet the flight would have produced sufficient pressure to blow the chutes, considering the flex of the potty walls, and the chutes being mounted in a horizontal tube. I just didn't see why they would go through the trouble to build such a rocket and then skimp on the recovery system. But I'm not trying to argue with you. For all I know, you built the thing, and know all of its details. But I would like to know how you know the electronics failed and the charge blew early.

I was there, I saw it fly first-hand, I know the people who built it, and I've seen the porta-potty afterwards, and discussed it with them. I also showed one of them photos to help him understand that it wasn't the parachutes that caused it to hit the ground under thrust, but rather that it was already falling over before the parachutes fully deployed.

In regards to tape, watch someone fly a spool sometime -- I've seen several people use masking tape to hold the parachute in place on top of the top plate.

There's no need to make something more complex than it has to be. Additional (unecessary) complexity just increases the odds of failure.

In the case of the porta-potty, inertia will push the parachutes down against the bottom of the horizontal tube. The cardboard and masking tape simply serve to keep the parachutes from sliding out; there is very little load on them.

Is it how I would have done it? No. Is it an acceptable solution? Yes.

-Kevin

 

[slim_t]

If the chutes were in a vertical tube, the forces would help, but not so much in the horizontal position.
Think about this though, as for what I was referring to about the pressure. My thought was this: The walls of the port-a-potty are pretty flexible, so once it lifts off, the walls may all get pushed in pressurizing the inside, thus pressurizing the chute tube, and pushing the chutes out. I'm not saying this is what happened. Just that it could have, and that "what if" would have been enough to call for a more secure hold on the chutes.

As for the spools, that only works while it is travelling straight up and the chute is being held down on the spool. If it were to tilt, the chute gets blown off, unless there's alot of tape. A simple X of tape has very little holding power. Even the one that flew before the potty came off before the ejection charge blew, but it was ok because of the very short thrust motor they used. If the potty had used similar short thrust motors, they probably would have had the same or better success.

Tim

 

[karatekicker271]

Originally posted by slim_t

Karatekicker, I appologize to you for this post. I wasn't going to reply, but then I figured it might be ok since you replied to the motor through the wall posts.
If you or the mods feel this was out of line, please delete it, or ask me to, and I will delete it myself.

I mean no anomosity in any of my posts, so please don't read any into it.

Tim

No problem. I was more trying to prevent people from getting in an all out flame war as to whether it was right or not. I may have taken the threats a little over board... lol. Thanks for the apology, even though it was not needed, I know nobody on this forum means any harm towards others...

 

[Rocket Guy 1317]

The masking tape had nothing to do with the early deployment, and with the way the parachute compartments were built, it was fine. The parachutes came out early because the electronics detected apogee early due to some design problems.

Are you talking Hill Billy Rocketry and there spool rocket? It was a very interesting rocket.

But my favorite of the low flying rockets was the out house rocket that built by Ky and his team.

 

[jraice]

no i believe they are talking about the outhouse project on two M1419's.