Storm the Castle B

[crazyhorse]

The projectile and counterweights were odd numbers so I don't remember them exactly. I know one projectile was 42.1g and the counterweights were also with decimal numbers too. I have read and re-read this years scoring for storm the castle and don't see anywhere where it states extra points for distance. Scoring is total distance(td)-3 times accuracy + bonus points for hitting target. I would love a better explanation to understand how the scoring works with longer distances since it isn't making sense to me based on the rule book info for this year.

The last post explained it very well. You dont get extra points for a farther distance, you just get more points. Team A chooses a target distance (td) of 3 meters. They start with a base of 3 points. They hit and land in the target. They get an accuracy bonus (ab) of (td)x .3. 3 x .3 = .9. (td) of 3 plus (ab) of +.9 = score of 3.9. Team B chooses a (td) of 20 meters and start with a base of 20 points. They miss the target by 5 meters. They get an (ab) of the miss (5 meters) x 3. 5 x 3 =15. (td) of 20 minus (ab) of 15 = score of 5.

You dont get bonus points for a longer distance, you just get moe to start. It is a combination of accuracy and distance in this event. If you are picking a target distance where u can miss by 2-3 meters based on data, ur asking to not medal. Based on ur data collection, pick a (td) u can get close to or hit with the given counterweight and projectile mass.

[sandpas]

There is a scoring spreadsheet at the official site that does the calculations for you. http://www.soinc.org/storm_the_castle_b You can plug in the numbers and see what scores you get.

[mtheleman]

...We have a hinged counterweight trebuchet with a wire "scoop" shape to hold the projectile (not a sling). We tried a sling with our trebuchet and it wasn't successful. Needless to say it doesn't have a lot of height in shooting the projectile, but is consistent with distance...

We're in the same boat, switching from a sling to a "scoop". My concern is with the energy conservation rule. My understanding is that, with a standard trebuchet, as long as the arm does not move forward at 90degrees or less, that this construction would work. That is, with a scoop attached to the end of the arm, as long as it does not move it forward at 90degrees, this would be permitted.

I have searched the forums, wikis, website, rules book - but do not see anything restricting/permitting a scoop as long as it meets energy rule. Can someone else share their thoughts on this and help put my mind to ease?

I have seen several interesting designs with scoops. You could potentially place the projectile closer to the end of the action of the arm. That would allow the arm to build up more momentum before carrying the projectile.

[Friedoyster3]

Does anyone have any tips as far as sling shape/design qualities. I've noticed that the projectile occasionally slips out of the sling some how and is ejected in the opposite direction and I'm fairly confident it is due to the sling. Is there one universal sling shape that fixes this problem?

[Tramsarran]

That's part of what I feared this year using a sling, and I witnessed the disadvatages of an improperly contructed string last year with my team's trebuchet. I was afraid that either the object would get caught in the sling, it would fall out too early at low launch speeds, or it wouldn't launch as confidently as with the cup I used at Regionals. Won 4th place, and that was due to my mistake of selecting a heavier projectile over the lighter one, and landing .5m from the target once.

[Friedoyster3]

You really shouldnt be afraid of slings, they work fine and greatly increase distance. Especially for a lower power machine(ie less than 10m with 1kg and ~35g). Slings only become a problem(as far as ejecting the ball backwards or sideways for that matter) once you get a machine that is capable of something like 15m with 1kg 35g (from my personal experience) where the sling accelerates quickly.

[YellowCurtainZ]

Just to clarify, the device just has to fit in a 65 by 65 cm cube before it goes into launch motion? so after it launches, if a part sticks out of the 65 x 65 cm cube, it is ok?

[wlsguy]

Just to clarify, the device just has to fit in a 65 by 65 cm cube before it goes into launch motion? so after it launches, if a part sticks out of the 65 x 65 cm cube cube, it is ok?

You are correct. The device must fit in the 65cm cube before launch WITH the projectile and counterweight. It CANNOT stick out of the "launch area" (the 1.0m square) before or after. This has been an issue with some teams in the past because they push the device all of the way forward in the launch area and it moves or something similar. If this happens, it violates rules 5 C V and will result in a 3 point penalty

[Platypus]

What kinds of wood are you guys using for the throwing arm? I need the arm to be light and strong, but all the woods that I saw at Lowes seemed too heavy...

[Friedoyster3]

Use aluminum on my arm. If you've never worked with it before it can be intimidating however I prefer working with aluminum and actually like it more than working with wood. To be specific I have 3/8" C (U-shaped) channel. C channel does have its limitations because if you were to torque it from either end it twisted which is why some people say used box tubing instead. But overall aluminum is lighter and stronger that wood