Air Trajectory B/C

[bernard]

This was posted on the NorCal state competition faq page
"Question: If a student blows into a soda bottle to restore it's shape after a launch, is that allowed under rule 3b. (I believe it's the same rule B and C division) The issue came up at Regionals, with disagreement about whether changing the shape of the bellows manually post launch is allowed. (if not allowed, how would this be different from the mass as a piston which fills the tube design which must by necessity change it's volume between launches).
ANSWER Device must return to ambient air pressure by itself (rule 4c) as the machine is reset for another launch. No pumps or re-inflating a container using any outside energy, other than energy used to reset the devise for another launch, may be used."

This makes no sense. I assume the intent was to clarify you can't pre pressurize the device but if the proctor doesn't allow any inflating even though it is used to "reset the device" according to the part that says "other than energy used to reset the device for another launch". My device (which uses an ball which is compressed by the falling mass) complies 100% to the rule that states it has to start and return to ambient air pressure. Now I'm deathly afraid I have to rebuild in a week... *bangs head against wall in confusion/frustration*

"Device must return to ambient air pressure by itself (rule 4c) as the machine is reset for another launch." is correct but does not directly address what the student is asking about, as you have pointed out.

A device's air container that is exposed to the air of the room automatically returns to ambient air pressure. By the answer, you can't even use a bike pump because lifting the handle of the bike pump would count as re-inflating a container (since air fills the inside of the bike pump).

If you can, I recommend contacting the event supervisor or the tournament director. Explaining what you are doing and how it isn't allowed by the FAQ might help him/her understand why the FAQ seems unreasonable.

[BuildistFromTheNorth]

Ya I'm talking with my coach tomorrow about it and hopefully we can sort it all out. It's just stressful that this is happening the week before competition. I agree with you that it would seem like you can't even use a pump but I could see them allowing a piston design on the basis that all you are doing is lifting up the mass. Hopefully the proctor is cool about it and this all works out. I did just try and reset the shape of the ball without using a pump and just using my hands and it did work which is in accord with the national FAQ that talks about using your hands to bring a soda bottle back to shape so hopefully I can use that if I need to... even though state FAQs supersede national FAQs at the state level.

[chalker]

.... even though state FAQs supersede national FAQs at the state level.

I'm glad you brought this up here. I wasn't aware of this specific FAQ, and while State FAQs do overrule National ones, I've reached out through my contacts to suggest this particular state FAQ be changed.

[BuildistFromTheNorth]

.... even though state FAQs supersede national FAQs at the state level.

I'm glad you brought this up here. I wasn't aware of this specific FAQ, and while State FAQs do overrule National ones, I've reached out through my contacts to suggest this particular state FAQ be changed.

Thank you so much!!!

[chalker]

Seems like some of the videos I've seen for the Air Trajectory trial event had raised targets, which could be an extra challenge but it doesn't seem much harder than than making it into the bucket, just that the raised targets would be less of a yes/no deal like the bucket shot is. Raised targets would have challenges of measuring shots that land too far away since you can't raise a large section of the landing area.

We've gotten away from the raised targets because they are a logistically nightmare for event supervisors to make / transport / setup / measure / etc.

[bernard]

Seems like some of the videos I've seen for the Air Trajectory trial event had raised targets, which could be an extra challenge but it doesn't seem much harder than than making it into the bucket, just that the raised targets would be less of a yes/no deal like the bucket shot is. Raised targets would have challenges of measuring shots that land too far away since you can't raise a large section of the landing area.

We've gotten away from the raised targets because they are a logistically nightmare for event supervisors to make / transport / setup / measure / etc.

Instead of raised targets on the ground, what if we had vertical targets (possibly on a white board or wall) and the goal was to hit the vertical target at a certain height from a certain distance (where the target point is raised off the ground)?

[ckssv07]

I think Bernard has a pretty good idea, another suggestion would be to not have the targets dead center. Another suggestion would be to possibly weight vertical deviation more than horizontal, i.e. Vd^3/2 +Hd, as I feel that the main focus of the event is trying to get the vertical component perfected since the horizontal should be fine as long as the device is angled properly. Possibly placing a cup at the target point, and if you land the projectile in the cup itself it could be a bonus like the centerline in wheeled vehicle last year, so the distance score would be 0 for all practical purposes, and then add a 100 point bonus for getting the ball in the cup. These are all just ideas that I think would make the event a bit more competitive and fun.

[zandermar18]

I don't think that using a non center target adds that much of an extra challenge. Even if the only measurements given by the supervisor were distance away and distance left or right, it would be a matter of using the Pythagorean theorem which the students can use their calculators for. Aiming would not be that much of an additional challenge because you could just use a laser sight.

[bernard]

I don't think that using a non center target adds that much of an extra challenge. Even if the only measurements given by the supervisor were distance away and distance left or right, it would be a matter of using the Pythagorean theorem which the students can use their calculators for. Aiming would not be that much of an additional challenge because you could just use a laser sight.

You wouldn't want the event to be too challenging since then some teams might be unable to do it, but I agree that the non-center targets aren't much of an added challenge since they are basically the bucket shots from this year (which many teams have been attempting).

[jennyk]

Don't know if this question has come up yet, but we were wondering if the clock stops on the 8 min allowed for the 4 attempts while the judges are measuring the distance. Sometimes they can take quite a while. And if the clock does stop, are you allowed to be setting up the next attempt, or is that not allowed?