General Discussion

[lucwilder42]

Does anybody know the top efficiency for Division C?

Solon, if I remember, got 97 and change.

Not too shabby

[thsom]

yea, about 6.9-7 grams assuming it was 70 cm and held all mass

[lucwilder42]

yea, about 6.9-7 grams assuming it was 70 cm and held all mass

I had a full height 6.67 gram tower hold it all about two weeks before our regional tournament this year, and unfortunately I wasn't able to replicate it all season. But, that's how towers goes. As frustrating as it can be, I'll miss it next year.

[thsom]

Yea, sometimes you just get some lucky balsa/bass.

[havenguy]

yea, about 6.9-7 grams assuming it was 70 cm and held all mass

I had a full height 6.67 gram tower hold it all about two weeks before our regional tournament this year, and unfortunately I wasn't able to replicate it all season. But, that's how towers goes. As frustrating as it can be, I'll miss it next year.

A week before Nationals, we made a 7.2 gram tower that held 13 kilograms. We thought that, by increasing the weight (and strength) of the tower, it would hold the whole thing. So we brought an 8.6 gram tower to Nationals, confident that it would hold full. It broke at 11.5, because one piece popped off, making the chimney shear and twist. At least we still got 16th.

[fishman100]

Spec for 2008:
Attachment: 2 bolts
Distance between bolts: 20 cm
Distance from wall: 40 cm
Max height: 15 cm

Wouldn't the tension members only have to carry ~43 kg since the distance from the wall is 40 cm, not 50?

(My work: If a boomilever is 15cm tall and extends 40 cm from the wall, then the angle at the distal end should be 20.56 degrees, assuming that my math is right and there is a perfect right angle. Plug that into the formulas you gave in your PDF (FAB = FAC x cos(20.56) and FAC x sin(20.56)-15=0) and I got FAC = 42.71...)

[SLM]

Spec for 2008:
Attachment: 2 bolts
Distance between bolts: 20 cm
Distance from wall: 40 cm
Max height: 15 cm

Wouldn't the tension members only have to carry ~43 kg since the distance from the wall is 40 cm, not 50?

(My work: If a boomilever is 15cm tall and extends 40 cm from the wall, then the angle at the distal end should be 20.56 degrees, assuming that my math is right and there is a perfect right angle. Plug that into the formulas you gave in your PDF (FAB = FAC x cos(20.56) and FAC x sin(20.56)-15=0) and I got FAC = 42.71...)

Yes, if the distance is 40 cm, the maximum tension force would be 43. I was using 50 cm as an example. For next year's project, we are not going to know the actual specifications until the official events and rules are published.

[susen]

I am a newer in the forum
and thank u for your sharing

[iYOA]

is there going to be a "best of nationals 2012" page on the wiki this year?