Boomilever B/C

[Unome]

With the projection only being 40-45 cm, I think the scores will be considerable higher than they were in 2014.

That much of an increase with only a 5 cm reduction? (granted I haven't done the relevant calculations)

[dholdgreve]

With the projection only being 40-45 cm, I think the scores will be considerable higher than they were in 2014.

That much of an increase with only a 5 cm reduction? (granted I haven't done the relevant calculations)

If I remember correctly, 2014 had a projection of 50 cm, which could mean a reduction of as much as 20% horizontal, with no change in height, so the angle is increased. I think we will see scores 20 to 25% higher than in 2014! JMHO... These types of events have gotten substantially more competitive over the years with the advent of digital stress modeling and 3-D printing of templates, etc... The increases may even be higher than that!

[Raleway]

"c. Participants may NOT bring any equipment such as levels or squares"

Why is that a thing...?

[TheChiScientist]

Could be to prevent on sight modification? Not sure how though...

[dholdgreve]

"c. Participants may NOT bring any equipment such as levels or squares"

Why is that a thing...?

A couple thoughts...
Having a level to check the plumb of the wall could create a reason for appeal, if the wall were out of plumb.
If the wall were out of plumb, the E/C would be faced with 2 choices: 1) adjust it accordingly, thus changing the parameters for all that follows, meaning those that went before the adjustment may be at a disadvantage, or 2) Leave it as is and continue testing, knowing that it is out of plumb, thus calling into question the entire legitimacy of the event. Neither are good answers. Sometime it is just better to not know.

Even if competitors checked to see if their boom was level, since you are not able to modify after check-in, the point is moot, and since a boom must be in 1 piece, shimming would / should not be allowed either.

[Raleway]

"c. Participants may NOT bring any equipment such as levels or squares"

Why is that a thing...?

A couple thoughts...
Having a level to check the plumb of the wall could create a reason for appeal, if the wall were out of plumb.
If the wall were out of plumb, the E/C would be faced with 2 choices: 1) adjust it accordingly, thus changing the parameters for all that follows, meaning those that went before the adjustment may be at a disadvantage, or 2) Leave it as is and continue testing, knowing that it is out of plumb, thus calling into question the entire legitimacy of the event. Neither are good answers. Sometime it is just better to not know.

Even if competitors checked to see if their boom was level, since you are not able to modify after check-in, the point is moot, and since a boom must be in 1 piece, shimming would / should not be allowed either.

Even if that's true, that's very disadvantageous to those who pursue high score designs. At that point, any deviation from the assumed "level" testing device is a much quicker failure. With my experience at States, the tables were NEVER level. However, we made sure to check this during impound as so we would not have an unfair advantage. In this way, it discourages those to try for ambitious designs which goes against the spirit of developing higher and higher scores. At one invitational where we did this, the ES checked the levelness after every few structures or at a request to ensure fairness- it was a simple adjustment of placing paper under the pegs. Just my two cents.

[dholdgreve]

"c. Participants may NOT bring any equipment such as levels or squares"

Why is that a thing...?

A couple thoughts...
Having a level to check the plumb of the wall could create a reason for appeal, if the wall were out of plumb.
If the wall were out of plumb, the E/C would be faced with 2 choices: 1) adjust it accordingly, thus changing the parameters for all that follows, meaning those that went before the adjustment may be at a disadvantage, or 2) Leave it as is and continue testing, knowing that it is out of plumb, thus calling into question the entire legitimacy of the event. Neither are good answers. Sometime it is just better to not know.

Even if competitors checked to see if their boom was level, since you are not able to modify after check-in, the point is moot, and since a boom must be in 1 piece, shimming would / should not be allowed either.

Even if that's true, that's very disadvantageous to those who pursue high score designs. At that point, any deviation from the assumed "level" testing device is a much quicker failure. With my experience at States, the tables were NEVER level. However, we made sure to check this during impound as so we would not have an unfair advantage. In this way, it discourages those to try for ambitious designs which goes against the spirit of developing higher and higher scores. At one invitational where we did this, the ES checked the levelness after every few structures or at a request to ensure fairness- it was a simple adjustment of placing paper under the pegs. Just my two cents.

Rale,
I don't disagree with anything you said... I'm just trying to apply any type of logic that may fit... As an E/C I agree that checking initially as well as frequently throughout the competition is an unwritten responsibility of those running it!

[Jacobi]

A couple thoughts...
Having a level to check the plumb of the wall could create a reason for appeal, if the wall were out of plumb.
If the wall were out of plumb, the E/C would be faced with 2 choices: 1) adjust it accordingly, thus changing the parameters for all that follows, meaning those that went before the adjustment may be at a disadvantage, or 2) Leave it as is and continue testing, knowing that it is out of plumb, thus calling into question the entire legitimacy of the event. Neither are good answers. Sometime it is just better to not know.

Even if competitors checked to see if their boom was level, since you are not able to modify after check-in, the point is moot, and since a boom must be in 1 piece, shimming would / should not be allowed either.

Even if that's true, that's very disadvantageous to those who pursue high score designs. At that point, any deviation from the assumed "level" testing device is a much quicker failure. With my experience at States, the tables were NEVER level. However, we made sure to check this during impound as so we would not have an unfair advantage. In this way, it discourages those to try for ambitious designs which goes against the spirit of developing higher and higher scores. At one invitational where we did this, the ES checked the levelness after every few structures or at a request to ensure fairness- it was a simple adjustment of placing paper under the pegs. Just my two cents.

Rale,
I don't disagree with anything you said... I'm just trying to apply any type of logic that may fit... As an E/C I agree that checking initially as well as frequently throughout the competition is an unwritten responsibility of those running it!

Here's the physics of the situation:

A wall tilting forward will put more stress on the tension member.
A wall tilting back will put more stress on the compression member.

Wood decreases strength the longer the compression chord is, while tension does not alter strength. Thus, it is reasonable to conclude that a wall tilting back could fatally shatter some designs.

A wall tilting forward would favor a compression boom, which is the less common type. A wall tilting back would favor the tension boom, which is the more common type.

A tower chimney design is favored by back-leaning. A box beam is favored by front-leaning. A compression tube is favored by front-leaning.

I hope this helps.

[kinghong1970]

While optimal situation is to have a perfectly perpendicular wall, the rule may be implemented so that all contestants are tested with the same level playing ground affecting, if any, benefits or disadvantages evenly throughout the numerous contestants...?

[Carrot]

Is a wall likely to have the plumb change throughout the day, like starting perfectly vertical but end up tilting? If so, would it be more beneficial to test within the first few blocks of an invitational in hopes that the wall started out closest to vertical at the beginning of the day?