Ping Pong Parachute B/C

[knightmoves]

Weird question: do you even have to have a nose cone? Isn't the bottom of the bottle sufficiently "blunt" by the bottle cap rule (3c)? We're trying out a funky design and I'm wondering if it'll violate the rules.

No, I think you're fine - there's no reason you can't just use the bottle bottom as is.

[1uwu1]

Hey!

I was wondering whether a flat nose cone would be considered "blunt"? We were thinking of using a PVC pipe at then just putting the ping pong on top. With the ping pong ball (before the launch), it is blunt but I don't know if a flat PVC pipe (after the parachute deploys) would still be blunt.

I don't see why it wouldn't be blunt. Obviously it passes the bottle cap test, but you're concerned about the "blunt or rounded" clause in that sentence. You're right that there's an "and" in that sentence, and so the nose must both satisfy the "blunt or rounded" condition and pass the bottle cap test. Something like a hole saw or a round metal cookie cutter, for example, would pass the bottle cap test, but would not be "blunt or rounded" - both have a sharp blade. A squared-off end of a bit of pipe isn't sharpened, though, and therefore is blunt.

Ok. Thanks!

[ET2020]

What have people done to prevent their rocket from flipping mid-flight? I've tried adjusting a few things but the rocket always seems to flip when it reaches the top, which is causing inconsistencies with parachute deployment.

[builderguy135]

What have people done to prevent their rocket from flipping mid-flight? I've tried adjusting a few things but the rocket always seems to flip when it reaches the top, which is causing inconsistencies with parachute deployment.

Second this question, we can't seem to make it stop flipping either.

[DragonTownEpic]

What have people done to prevent their rocket from flipping mid-flight? I've tried adjusting a few things but the rocket always seems to flip when it reaches the top, which is causing inconsistencies with parachute deployment.

Second this question, we can't seem to make it stop flipping either.

So, what I've found is that if the aerodynamics of the rocket are spot-on, the rocket will be sideways at the highest point, which is bad.
What I did was reduce the aerodynamics of the rocket, which you can do by decreasing the size of the fins or by adding mass to the bottom of the rocket. This causes the "flip" to occur later in the flight, hopefully after the parachute has detatched from the rocket.

[yugo]

Hi everyone!

I've been seeing many designs both online and in past competitions where the "nose cone" (if you could still call it that) was just some sort of straight plastic pipe-like thing that extended several feet further than the rocket body, with the ping pong ball sitting on top. I presume this is to keep the payload higher than the body so that it can get more air time/stability, but I have no idea how to construct such a system, and if it really is effective. I've seen a design that reached 14.5 seconds with 55 psi (don't know the ceiling height, sorry) and this seems pretty good. What is your opinion on this? Is it really worth it to create such a system?

Thanks, and sorry if my questions are amateurish - due to unforeseen circumstances, I have to work build events this year with little prior experience, and as such, am just getting introduced to the world of builds.

Happy holidays!

[xiangyu]

Hi everyone!

I've been seeing many designs both online and in past competitions where the "nose cone" (if you could still call it that) was just some sort of straight plastic pipe-like thing that extended several feet further than the rocket body, with the ping pong ball sitting on top. I presume this is to keep the payload higher than the body so that it can get more air time/stability, but I have no idea how to construct such a system, and if it really is effective. I've seen a design that reached 14.5 seconds with 55 psi (don't know the ceiling height, sorry) and this seems pretty good. What is your opinion on this? Is it really worth it to create such a system?

Thanks, and sorry if my questions are amateurish - due to unforeseen circumstances, I have to work build events this year with little prior experience, and as such, am just getting introduced to the world of builds.

Happy holidays!

Hello again, just replied to your question in gravity vehicle haha,

The idea with the pipe is to keep the payload away from the rocket to prevent entanglement and problems of separation due to the fins (in my opinion) and to also "prep" the parachute for immediate deployment position. In my opinion, it is fairly effective, but I'm sure there are other systems that achieve pretty much the same thing. In terms of construction, what my team did was first making a cone shape and taping it to the "top" (or really the actual bottom) of the bottle and then taping the pipe bu setting it to the "peak" of the cone. For us, this makes the system tougher to break and is easier to make sure everything is fairly straight.

What is the design of the 14.5 second one? 55 psi seems really high so either it's a pretty high ceiling or their rocket must be very heavy/not aerodynamic. In terms of the time, the rocket's role is to get the parachute up there in position, the real part of this competition that should take the most time imo is the parachute design/testing.

Xiangyu

[yugo]

Hi everyone!

I've been seeing many designs both online and in past competitions where the "nose cone" (if you could still call it that) was just some sort of straight plastic pipe-like thing that extended several feet further than the rocket body, with the ping pong ball sitting on top. I presume this is to keep the payload higher than the body so that it can get more air time/stability, but I have no idea how to construct such a system, and if it really is effective. I've seen a design that reached 14.5 seconds with 55 psi (don't know the ceiling height, sorry) and this seems pretty good. What is your opinion on this? Is it really worth it to create such a system?

Thanks, and sorry if my questions are amateurish - due to unforeseen circumstances, I have to work build events this year with little prior experience, and as such, am just getting introduced to the world of builds.

Happy holidays!

Hello again, just replied to your question in gravity vehicle haha,

The idea with the pipe is to keep the payload away from the rocket to prevent entanglement and problems of separation due to the fins (in my opinion) and to also "prep" the parachute for immediate deployment position. In my opinion, it is fairly effective, but I'm sure there are other systems that achieve pretty much the same thing. In terms of construction, what my team did was first making a cone shape and taping it to the "top" (or really the actual bottom) of the bottle and then taping the pipe bu setting it to the "peak" of the cone. For us, this makes the system tougher to break and is easier to make sure everything is fairly straight.

What is the design of the 14.5 second one? 55 psi seems really high so either it's a pretty high ceiling or their rocket must be very heavy/not aerodynamic. In terms of the time, the rocket's role is to get the parachute up there in position, the real part of this competition that should take the most time imo is the parachute design/testing.

Xiangyu

This is the link to the video. And I saw your response, thanks so much!
https://www.youtube.com/watch?v=HE4pT4yrq-g

[xiangyu]

This is the link to the video. And I saw your response, thanks so much!
https://www.youtube.com/watch?v=HE4pT4yrq-g

Thanks! We have a very similar design, our tube is shorter though. Wow, their tube is LONG!

[will0416]

The tube design pretty much eliminates any worries about flipping midflight if you get the center of mass right