Ping Pong Parachute B/C

[windu34]

Ping Pong Parachute B/C: Prior to the tournament, teams will design, build and bring up to two bottle rockets to the tournament to launch a ping pong ball attached to a parachute to stay aloft for the greatest amount of time.

Indoor Bottle Rocket Wiki

Past Threads: 2018

[andrewwski]

Looks like the rules do not give a maximum allowable pressure? This is going to need to be addressed.

[nicholasmaurer]

Looks like the rules do not give a maximum allowable pressure? This is going to need to be addressed.

Well 4.b. requires that teams justify their pressure selection using past trials (which should indicate their device can tolerate that pressure), and 5.c. requires the ES to verify they actually pressurized the device to the stated pressure. Also, since hitting the ceiling incurs a large penalty (Tier 3), I don't think in most spaces that an extremely high pressure would offer any advantage...

[jaggie34]

I'm curious, how long does everyone think top times will end up being?

[andrewwski]

Looks like the rules do not give a maximum allowable pressure? This is going to need to be addressed.

Well 4.b. requires that teams justify their pressure selection using past trials (which should indicate their device can tolerate that pressure), and 5.c. requires the ES to verify they actually pressurized the device to the stated pressure. Also, since hitting the ceiling incurs a large penalty (Tier 3), I don't think in most spaces that an extremely high pressure would offer any advantage...

That doesn't stop a team from trying a pressure that is too high during their testing. An exploding bottle can be dangerous, a maximum pressure would not give teams incentive to try any higher.

As an event supervisor, I'm also not going to trust the logs that any teams bring. I know especially at invitationals and regionals, a lot of them are made up (some of them probably the morning of).

There's also going to be statistical variation in the actual pressure that a bottle fails at, and there may even be weakening over multiple cycles. Just because a bottle handles 100 psi once doesn't mean it will continue to.

[jaggie34]

Looks like the rules do not give a maximum allowable pressure? This is going to need to be addressed.

Well 4.b. requires that teams justify their pressure selection using past trials (which should indicate their device can tolerate that pressure), and 5.c. requires the ES to verify they actually pressurized the device to the stated pressure. Also, since hitting the ceiling incurs a large penalty (Tier 3), I don't think in most spaces that an extremely high pressure would offer any advantage...

That doesn't stop a team from trying a pressure that is too high during their testing. An exploding bottle can be dangerous, a maximum pressure would not give teams incentive to try any higher.

As an event supervisor, I'm also not going to trust the logs that any teams bring. I know especially at invitationals and regionals, a lot of them are made up (some of them probably the morning of).

There's also going to be statistical variation in the actual pressure that a bottle fails at, and there may even be weakening over multiple cycles. Just because a bottle handles 100 psi once doesn't mean it will continue to.

Hopefully the pressure that teams will submit wont be great enough to cause the bottle to fail

[Unome]

Looks like the rules do not give a maximum allowable pressure? This is going to need to be addressed.

Well 4.b. requires that teams justify their pressure selection using past trials (which should indicate their device can tolerate that pressure), and 5.c. requires the ES to verify they actually pressurized the device to the stated pressure. Also, since hitting the ceiling incurs a large penalty (Tier 3), I don't think in most spaces that an extremely high pressure would offer any advantage...

That doesn't stop a team from trying a pressure that is too high during their testing. An exploding bottle can be dangerous, a maximum pressure would not give teams incentive to try any higher.

As an event supervisor, I'm also not going to trust the logs that any teams bring. I know especially at invitationals and regionals, a lot of them are made up (some of them probably the morning of).

There's also going to be statistical variation in the actual pressure that a bottle fails at, and there may even be weakening over multiple cycles. Just because a bottle handles 100 psi once doesn't mean it will continue to.

I thought much the same thing (in a less sophisticated internal monologue ) when I heard about this at SOSI.

[sciolyperson1]

I'm curious, how long does everyone think top times will end up being?

A time of around 7? Seconds I think won first at nj states (trial event).

[builderguy135]

I'm curious, how long does everyone think top times will end up being?

A time of around 7? Seconds I think won first at nj states (trial event).

That was 40 psi. Only went up a few feet. It's gonna be much higher this year, expect 10-20 second times.

Also, some launchers won't even go up to 100 psi. The one I used last year to practice only got up to 75, which already goes extremely high with 1 liter bottles. (50 feet?)

[andrewwski]

Well 4.b. requires that teams justify their pressure selection using past trials (which should indicate their device can tolerate that pressure), and 5.c. requires the ES to verify they actually pressurized the device to the stated pressure. Also, since hitting the ceiling incurs a large penalty (Tier 3), I don't think in most spaces that an extremely high pressure would offer any advantage...

That doesn't stop a team from trying a pressure that is too high during their testing. An exploding bottle can be dangerous, a maximum pressure would not give teams incentive to try any higher.

As an event supervisor, I'm also not going to trust the logs that any teams bring. I know especially at invitationals and regionals, a lot of them are made up (some of them probably the morning of).

There's also going to be statistical variation in the actual pressure that a bottle fails at, and there may even be weakening over multiple cycles. Just because a bottle handles 100 psi once doesn't mean it will continue to.

I thought much the same thing (in a less sophisticated internal monologue ) when I heard about this at SOSI.

So - this (lack of maximum pressure specification) is intentional?