Ping Pong Parachute B/C

[builderguy135]

At my most recent invitational, my school's ppp team didn't do so wear despite having a great parachute and rocket. The main problem was that the launcher is different and a 12psi from our launch (which would've sent the rocket up 15 ft, only sent it up 2-foot in the competition launcher. This basically rendered our data useless and on a second launch, which they increased the pressure to 20 psi, only managed to sent it up 4 feet. How do other teams deal with this uncertainty and inconsistencies between launchers?

Xiangyu

Have you tried bringing your own pump to competition?

[xiangyu]

At my most recent invitational, my school's ppp team didn't do so wear despite having a great parachute and rocket. The main problem was that the launcher is different and a 12psi from our launch (which would've sent the rocket up 15 ft, only sent it up 2-foot in the competition launcher. This basically rendered our data useless and on a second launch, which they increased the pressure to 20 psi, only managed to sent it up 4 feet. How do other teams deal with this uncertainty and inconsistencies between launchers?

Xiangyu

Have you tried bringing your own pump to competition?

No...is it a problem with the pump? Not the launcher? Darn cause we actually brought our own pump but decided against using it for some reason.

[builderguy135]

At my most recent invitational, my school's ppp team didn't do so wear despite having a great parachute and rocket. The main problem was that the launcher is different and a 12psi from our launch (which would've sent the rocket up 15 ft, only sent it up 2-foot in the competition launcher. This basically rendered our data useless and on a second launch, which they increased the pressure to 20 psi, only managed to sent it up 4 feet. How do other teams deal with this uncertainty and inconsistencies between launchers?

Xiangyu

Have you tried bringing your own pump to competition?

No...is it a problem with the pump? Not the launcher? Darn cause we actually brought our own pump but decided against using it for some reason.

My pump that reads 40 psi might be 50 psi in yours, so use your own pump. Changing the launcher might be different by a little, but not by much.

[maxvadas]

I've been using produce bags as my parachute material, but I can't seem to get above about 15 seconds in my 20-foot gym. Any ideas for a better parachute material?

[CookiePie1]

I've been using produce bags as my parachute material, but I can't seem to get above about 15 seconds in my 20-foot gym. Any ideas for a better parachute material?

what kind of produce bags have you been using? How thick are they? Try finding reallllly thin bags and see if that helps

[sciolyperson1]

I've been using produce bags as my parachute material, but I can't seem to get above about 15 seconds in my 20-foot gym. Any ideas for a better parachute material?

Not a bad choice, produce bags tend to be thin due to it being cheaper to produceheh, however one limiting factor is the size of the bags. How large is the diameter of your parachute?

[maxvadas]

Merry Christmas!

My parachute diameter is eighteen inches since I found a produce bag for fish at Whole Foods, but I can't seem to find anything bigger than that.

[hyoung]

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.

[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.

[knightmoves]

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.