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### Re: Junkyard Challenge B

Posted: March 8th, 2011, 5:09 pm
around 10 meters with the catapult, but extremely inaccurate

### Re: Junkyard Challenge B

Posted: March 8th, 2011, 8:41 pm
I ask a few questions of those who have done catapult and or bouncer at your competitions.
Rankings are determined by the direct, straight-line distance measured in mm from the closest edge of the catapult/bouncer to the closest edge of the target plate. Bonus points are earned for hitting the target plate.
1. If hitting the target plate is just a bonus, why don't people put the target plate 100 yards away from your bouncer/catapult? Nothing in the rules says it has to hit the plate for it to be counted, so why don't people just place it very far away?

2. What physically will target plates be?

3. How many launch attempts will you have?

4. With what ball will you launch

5. For bouncer, how will the judges prevent people from throwing the ball, instead of dropping?

6. Also for bouncer, what if you miss the bouncer dropping the ball? Does that count as a launch attempt?

These may be stupid questions, as it may just be me, but I felt completely lost reading the scoring for them in the rules. Thanks for anybody who can help!

### Re: Junkyard Challenge B

Posted: March 8th, 2011, 10:46 pm
I ask a few questions of those who have done catapult and or bouncer at your competitions.
Rankings are determined by the direct, straight-line distance measured in mm from the closest edge of the catapult/bouncer to the closest edge of the target plate. Bonus points are earned for hitting the target plate.
1. If hitting the target plate is just a bonus, why don't people put the target plate 100 yards away from your bouncer/catapult? Nothing in the rules says it has to hit the plate for it to be counted, so why don't people just place it very far away?
It is true that the students could put the target 100 yards away and never hit the target distance0 but they would only receive participation points if they did so. (5.e) The students have to demonstrate that their device is capable of hitting their target distance (even if they aren't able to hit their actual target plate) else they will receive only participation points.
2. What physically will target plates be?
The plates will be either paper or Styrofoam that are impounded by the students (2.b.iv)
3. How many launch attempts will you have?
This will depend on how many balls the students choose to use, students will have 2 minutes to finish releasing their chosen balls. (5.g)
4. With what ball will you launch
Students will be allowed to determine which type and number of balls they wish to use; they may use plastic golf balls, standard golf balls or standard tennis balls. (5.a)
5. For bouncer, how will the judges prevent people from throwing the ball, instead of dropping?
This will be up to the judges. There are ways such as making each student hold the ball in the palm of their hand and letting them release the ball.
6. Also for bouncer, what if you miss the bouncer dropping the ball? Does that count as a launch attempt?
I think it will, 5.g says that each ball may only be released by the team once. Besides, you have multiple balls so it shouldn't be a problem.

### Re: Junkyard Challenge B

Posted: March 9th, 2011, 3:55 am
Accuracy is also very key in this event. To hit the target Rule 5f says the bonus is D x (1+n) D = distance scored n = number of balls hitting the target.
So a team that gets 1 20 meter launch will get beat by the team that gets 10 3.75 meter launches. It puts a huge emphasis on accuracy and less on distance.

### Re: Junkyard Challenge B

Posted: March 10th, 2011, 10:29 pm
What kind of triggers have you built for catapault? I can't seem to find a trigger that works as well ( or nearly as well) as actually pulling back with my hand.

### Re: Junkyard Challenge B

Posted: March 11th, 2011, 3:53 pm
What kind of triggers have you built for catapault? I can't seem to find a trigger that works as well ( or nearly as well) as actually pulling back with my hand.
Well is it legal to not use your hand but use a cup/plate/some other material to hold it?
I have great ideas for all of these state devices

Current:
Tower: 9 feet tall
Bridge: 20 feet long
Cantilever: 10 feet long

### Re: Junkyard Challenge B

Posted: March 11th, 2011, 4:53 pm
For regionals, we had towers, so I got 206 cm with a golf ball on top.
State, we're using the same strategy with the structure of tower.

### Re: Junkyard Challenge B

Posted: March 13th, 2011, 7:25 am
I went to regionals (and is going to state ). They had us build a cantilever. However, the guy managing the event allowed use of non-free standing balls. For example, one team made a cup holder for their cup, and another used straws to keep theirs from sliding down. So be sure to ask the event manager A LOT of questions, including what he/she defines as a freestanding cup.

### Re: Junkyard Challenge B

Posted: March 14th, 2011, 4:49 pm
What kind of materials are you guys using to make the arm of the catapult?
I can't seem to find anything strong enough to take the strain of heaving a golf ball more than a couple of meters.

### Re: Junkyard Challenge B

Posted: March 14th, 2011, 4:50 pm
around 10 meters with the catapult, but extremely inaccurate
With what ball are you achieving 10 meters?