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Re: Storm the Castle B

Posted: March 8th, 2011, 2:29 pm
by JSGandora
Yes, you are correct.

Re: Storm the Castle B

Posted: March 8th, 2011, 7:24 pm
by Liv
earthbot25 wrote:is the consensus that leather slings work very well?
I am still trying to find a sling that is consistent
From my experience I have observed that the leather sling works very well and really holds the projectile. A thin cloth sling can cause many problems and can deploy the projectile to early.

Re: Storm the Castle B

Posted: March 8th, 2011, 8:29 pm
by hirasia
Since there's only a week left until NJ States, and our trebuchet hasn't been worked on by the people who were supposed to (taken over by other building people)
What do you suggest to do? Would it be legal to have a "seesaw" with a cup to hold the projectile screwed onto the arm
currently, the sling is throwing the projectile backwards
It's a standard counterweight trebuchet, not the FAT that everyone says does really well
Since we only have a week to finish building and calibrating, what would be the best to do for this?
with the "seesaw" idea, it's only flinging the projectile about 6 meters, not good enough for states

Re: Storm the Castle B

Posted: March 9th, 2011, 5:20 am
by wlsguy
hirasia wrote:Since there's only a week left until NJ States, and our trebuchet hasn't been worked on by the people who were supposed to (taken over by other building people)
What do you suggest to do? Would it be legal to have a "seesaw" with a cup to hold the projectile screwed onto the arm
currently, the sling is throwing the projectile backwards
It's a standard counterweight trebuchet, not the FAT that everyone says does really well
Since we only have a week to finish building and calibrating, what would be the best to do for this?
with the "seesaw" idea, it's only flinging the projectile about 6 meters, not good enough for states
Keep the sling. You need it for distance. Also, your sling should be approximatly the same length as your arm from the pivot to the tip.

Anyway, your problem is likely your pin angle. First, mark your current angle. Then adjust your pin angle "forward" (i.e. in the direction of rotation of the tip of the arm). Do this in small (~10 degree) increments until the machine starts shooting like a baseball pitching machine. Mark this position. Find the spot halfway between the two and this should be close to a nice 45 degree release. More pratice will let you find the best position.

Once you try this, post again so more help can be provided if needed. Good Luck.

Re: Storm the Castle B

Posted: March 13th, 2011, 5:34 pm
by g0lmal
Does any one know what they mean by the follwoing rule (Construction . Rule D) ? It is very confusing..

"The edge of the hole must be no more than 1 CM from the edge of material" - Which material is refferd in this rule? Counter weight or the ARM?

Thanks

Re: Storm the Castle B

Posted: March 13th, 2011, 8:55 pm
by chalker
g0lmal wrote:Does any one know what they mean by the follwoing rule (Construction . Rule D) ? It is very confusing..

"The edge of the hole must be no more than 1 CM from the edge of material" - Which material is refferd in this rule? Counter weight or the ARM?

Thanks

We've seen a lot of questions about this. It's referring to the arm. The whole point of this rule is to ensure that the event supervisor counterweight and hook can actually hook onto the competitor provided device.

Re: Storm the Castle B

Posted: March 14th, 2011, 8:03 am
by g0lmal
It does not make sense.. 1 CM = 0.393 Inch. If you are required to use 6.5 mm (0.25 Inch) hook, it does not leave enough space to sustain the force.

Any ideas to get aroung this?

Thank you

Re: Storm the Castle B

Posted: March 14th, 2011, 8:30 am
by fleet130
g0lmal wrote:it does not leave enough space to sustain the force.
Para. 3.d, line 4: "The edge of the hole must be no more than 1 cm from the edge of the material."
Image(not to scale)

Note: The hook is supplied by the event supervisor as part of the counterweight.

The EDGE (not the center) of the hole is one cm from the edge of the material.

One cm of almost any metal 6.5 mm (1/4 in) thick should be strong enough to support the specified counterweight throughout a launch motion. Part of the problem is for you to figure out how it can be done.

As someone mentioned, this is to ensure you will be able to attach the counterweight to your STC device. Event supervisors should construct a similar item to use as a test jig to be sure their counterweight works on team's devices.

Re: Storm the Castle B

Posted: March 14th, 2011, 9:59 am
by g0lmal
Just to confirm.. I can have 1/4 inch EYE going through the ARM at 1 Inch from the edge.. As long as I can provide a way to hoock the CW..

Re: Storm the Castle B

Posted: March 14th, 2011, 7:46 pm
by fleet130
g0lmal wrote:Just to confirm.. I can have 1/4 inch EYE going through the ARM at 1 Inch from the edge.. As long as I can provide a way to hoock the CW..
It's all about being able to connect the counterweight to your STC device. If your attachment point (hole for the counterweight hook) meets the specifications given in Para. 3.d, the counterweight will fit. If your attachment point doesn't meet the stated specifications, you may not be able to attach the counterweight to your device.

If I understand your description correctly, it is irrelevant where the eye attaches to the arm. The "hole" mentioned in the rules is the hole in the "eye". That hole must meet the specifications to insure the counterweight hook will fit. For example: if the eye is made from 5/16 diameter rod, the opening in the counterweight hook may be too small to allow the body of the eye to pass through to connect the counterweight to the eye.

Note: Para. 3.d line 2, states that this requirement only applies if: "the hook is used to attach the counterweight". Event supervisors may/may not interpret this paragraph to be a requirement (it is stated as such) and penalize devices that don't comply, even though the counterweight can be attached.