Storm the Castle B

[starpug]

He's young at heart!

I certainly am. And in any case, I could bring myself to work on it but I won't because apparently I'm too old for the fun events!

This calls for the formation of a middle school team

[brobo]

A few teamates of mine had a good question: would gears be considered a violation of the energy rule?
Technically gears are not a form of potential energy, but they do change how the arm moves.
What do you guys think? If I added gears to my trebuchet (not that I want to) would that violate the almighty energy rule?

[fleet130]

Gears only change the direction/magnitude/speed/distance of the motion generated by using the energy stored in the counterweight. Unless they somehow provide additional energy, they should be allowed.

[Liv]

Okay, first year doing this, I think I'm doing this event because of trajectory, could anyone give me a summary of the event?

[AlphaTauri]

Think Trajectory, but with a trebuchet powered by a falling counterweight instead of a catapult powered by elastic energy. (Gah, my spell check doesn't even recognize "trebuchet" as a word.)

[Liv]

Think Trajectory, but with a trebuchet powered by a falling counterweight instead of a catapult powered by elastic energy. (Gah, my spell check doesn't even recognize "trebuchet" as a word.)

Oh okay, seems rather easy. So that means I'd have to build a trebuchet. Well, I better get working on sketches or just ideas on the counterweight! Thanks!

[brobo]

Think Trajectory, but with a trebuchet powered by a falling counterweight instead of a catapult powered by elastic energy. (Gah, my spell check doesn't even recognize "trebuchet" as a word.)

Oh okay, seems rather easy. So that means I'd have to build a trebuchet. Well, I better get working on sketches or just ideas on the counterweight! Thanks!

Uhhh, have you read the rules at all? That's not how this event works.

You design a trebuchet, and then test it and make graphs/charts to show how far the projectile will go with different masses of projectile and counterweight. When you get to the tournament, the judges give you both the projectile and counterweight you are to use- you don't get a say at all. Then you have to design how far you want the target set up. That also brings accuracy into the factor. If you're too confident, you'll undershoot, and if you're trying to play it say, you'll overshoot.

I would head over to the Storm the Castle Wiki, it has a lot of different types of trebuchets on display.

[5asdffdsa5]

Here's a brief rundown of the event for 2011 (Maybe not so brief!):

...1..Powered by falling mass (counterweight & projectiles only)
...2..Projectiles, counterweight, & target supplied by event supervisor
......a..Exact Mass & size not known before competition
......b..May not be modified by contestants
......c..Device must be constructed to accommodate
...3..Counterweight
......a..1-3kg
......b..Counterweight & hook fit in 15cm cube (be prepared for diagonal fit dimensions)
......c..Hook - use is optional
......d..To insure hook fits the device (this is not scoreable, but counterweight may not fit otherwise)
............1).Must have hole at least 9mm dia.
............2).Edge of hole must be no more than 1cm from edge of material
............3).Material must be no more than 6.5mm thick
...4..Projectiles
......a..20-60g
......b..Approximately spherical
......c..No larger than 6cm dia.
......d..Multiple projectiles (if used) will have similar size, shape & mass.
...5..Target
......a..20cm x 20cm x 20cm
......b..Open Top
...6..Entire device (including counterweight & projectile) must fit in 75cm cube when ready-to-fire
...7..Must automatically return to within launch area after each shot
...8..Trigger
......a..is not part of device
......b..May extend out of launch area (before, during &after launch)
......c..May use battery power
......d..May not use radio control (Safety Hazard)
...9..Devices may be modified (using only tools & supplies impounded)
...10. 5 minutes, 3 launches, no practice shots
...11. Need Z87+ (high impact) eye protection (Does not specify type)

Somewhere in the archives, there may be a lengthy discussion on the use of the various types of trebuchets. While it may be possible to build a FAT that complies with the energy rule, complying with the sentence in lines 5 & 6 of Para. 3.f makes it questionable whether it could be viable.
(Edit: I found the info on the energy rule. I have not validated it against the current rules.)

Be sure to read the rules extra carefully. There are lots of pitfalls where you can mis-interpret things. Make sure you understand the "energy rule" (Para. 5.f). This has historically been one of the things teams get burned on.

Caveat Emptor! This is not the rules. Be sure to double-check yourself once you get them. I've tried not to make interpretations and to identify them when I do.

What are Z87 goggles

[brobo]

Its a very specific type of saftey goggle. Ask your coach, they should have some.

[fleet130]

What are Z87 goggles

See: http://soinc.org/eye_protection

There are 4 types of eye protection. The rules don't identify which type must be worn, only that they must meet the high impact (Z87+) standard.

[mr popper70]

1-3kg
Counterweight & hook fit in 15cm cube (be prepared for diagonal fit dimensions)
Hook - use is optional
To insure hook fits the device (this is not scoreable, but counterweight may not fit otherwise)
Must have hole at least 9mm dia.
Edge of hole must be no more than 1cm from edge of material
Material must be no more than 6.5mm thick

"Does this mean we must build our designs compatiable for a hook weight?"
and or do the judges supply the counter weight?
or does it mean if we have a hook design we must follow the guidelines?

[JBoyd-NY]

Event Supervisors supply the counter-weight, the projectile, and the "castle". Expect the counter-weight to have a hook to attach to the arm of the trebuchet. Mass of the projectile and counter-weight and type of projectile will be announced after impound has been completed.

[mr popper70]

Will there same weights and distances for everyone? also your opinion how would i construct my trebuchet to be ajustable for a set weight?

[JBoyd-NY]

You determine the distance of the target, based on the calibrations you did during practice. That's where the graphs come in - you practice with different masses of counter-weights, different masses of projectiles, and different types of projectiles, and plot the results on your graphs. Once you find out the mass of the counter-weight, the mass of the projectile, and the type of the projectile, you use the appropriate graph to help determine how far your trebuchet will throw the projectile, then tell the Event Supervisor to place the castle at that particular distance.

[mr popper70]

OK Thank you so much!!! i had no idea you were allowed to move the castle