Pictures, Videos, and Scores

[bernard]

I did use 1/8 balsa, and sadly I cannot tell you the weight of our legs because I didn't keep track of the ones I used for legs/bracing. I know, my bad.

But for legs we went for legs with strengths of about 50-70 BS and for bracing we used more lighter sticks (like ones with strengths of 30-50).

Yeah, probably won't get a very good score (calculated it, will be about 375).

Congratulations, hearthstone224, on your beautiful tower. Keep working at lowering its mass.

[Balsa Man]

I did use 1/8 balsa, and sadly I cannot tell you the weight of our legs because I didn't keep track of the ones I used for legs/bracing. I know, my bad.

But for legs we went for legs with strengths of about 50-70 BS and for bracing we used more lighter sticks (like ones with strengths of 30-50).

Yeah, probably won't get a very good score (calculated it, will be about 375).

Congratulations, hearthstone224, on your beautiful tower. Keep working at lowering its mass.

Congratulations, indeed; it is a beautiful tower!

[Chameleon02]

Recently took 5th place medal for C division with a tower efficiency of around 1650. Top two for C division broke 2400, and top for B Division was just shy of 2000. The invitational was competitive, and I am still wondering why there was such a sizable gap between the divisions. Any thoughts?

[Random Human]

Recently took 5th place medal for C division with a tower efficiency of around 1650. Top two for C division broke 2400, and top for B Division was just shy of 2000. The invitational was competitive, and I am still wondering why there was such a sizable gap between the divisions. Any thoughts?

What state are you in?

[Chameleon02]

Recently took 5th place medal for C division with a tower efficiency of around 1650. Top two for C division broke 2400, and top for B Division was just shy of 2000. The invitational was competitive, and I am still wondering why there was such a sizable gap between the divisions. Any thoughts?

What state are you in?

Michigan

[embokim]

I am just wondering what some of your towers look like, like, how do you get it so light, because when i use wood sparingly (balsa) i get like 15g, and my tower doesn;t even hold all 15kg
Thanks

[Balsa Man]

Recently took 5th place medal for C division with a tower efficiency of around 1650. Top two for C division broke 2400, and top for B Division was just shy of 2000. The invitational was competitive, and I am still wondering why there was such a sizable gap between the divisions. Any thoughts?

What state are you in?

Those are some very interesting numbers, in a couple of ways. First, as far as I can see, B-Div towers should be lighter than C-Div ones. The load on the legs is only very slightly higher than on C towers (like a tenth of a kilogram) because of the slightly higher angle of the legs. And there's got to be about 40cm more leg wood (10cm x 4 legs) in a C-tower. Second, two C-towers breaking 2400 is, by my calculations, pretty amazing. If they met 29cm circle bonus, that's a 7gr tower weight, and if not, that's a 6.2gr tower weight (carrying full load). From a fair amount of calculations, that's really pushing the theoretical limits. I'd said earlier I wouldn't be surprised to see around 2400 by Nationals, but two, at an early season invitational; impressive. Michigan, historically, has been strong in the balsa structures events; looks like that trend is continuing.

I am just wondering what some of your towers look like, like, how do you get it so light, because when i use wood sparingly (balsa) i get like 15g, and my tower doesn;t even hold all 15kg
Thanks

No pics at this point, but a quick set of numbers to consider, and check your numbers against:
From design calcs- for a tower weight of just over 8gr; legs fm 1.45 gr/36" at 3.26gr; ladders (using 1/4 bracing interval - 0.9gr/36" for lowest ladder, 0.8gr/36 for ones above it) at 1.71gr; Xs at 2.19gr (3/32nds" wide x 1/64th" thick, from 9.5 gr 3" x 36" sheet), and glue a bit under 1gr.

[baker]

[quote="Balsa ManNo pics at this point, but a quick set of numbers to consider, and check your numbers against:
From design calcs- for a tower weight of just over 8gr; legs fm 1.45 gr/36" at 3.26gr; ladders (using 1/4 bracing interval - 0.9gr/36" for lowest ladder, 0.8gr/36 for ones above it) at 1.71gr; Xs at 2.19gr (3/32nds" wide x 1/64th" thick, from 9.5 gr 3" x 36" sheet), and glue a bit under 1gr.[/quote]

Now this sounds aggressive. I'm tempted to build this. Is this 'C' rules and bonus?

[Balsa Man]

[quote="Balsa ManNo pics at this point, but a quick set of numbers to consider, and check your numbers against:
From design calcs- for a tower weight of just over 8gr; legs fm 1.45 gr/36" at 3.26gr; ladders (using 1/4 bracing interval - 0.9gr/36" for lowest ladder, 0.8gr/36 for ones above it) at 1.71gr; Xs at 2.19gr (3/32nds" wide x 1/64th" thick, from 9.5 gr 3" x 36" sheet), and glue a bit under 1gr.

Now this sounds aggressive. I'm tempted to build this. Is this 'C' rules and bonus?[/quote]

No, B rules w/ bonus. For C, aggressive, same weight estimating calc numbers are 8.7gr tower; 3.75gr legs (1.4gr/36"); 2.28 ladders, using 1/5 interval bracing- 1gr/36" for the lowest, 0.8gr/36 for higher ones, 1.6gr for Xs (1/16 x 1/64, from 7.5gr 3 x 36" sheet), and 1.1 gr glue

[SPP SciO]

I am just wondering what some of your towers look like, like, how do you get it so light, because when i use wood sparingly (balsa) i get like 15g, and my tower doesn;t even hold all 15kg
Thanks

I'd be willing to guess that when you test your tower to failure, it doesn't seem to "explode" but instead just cracks in one or two spots and falls over. Most of the members and joints were plenty strong, there are just some weak spots in your design.

Careful wood selection and construction techniques will yield dramatic improvements.

Keep in mind: if you were able to see pictures and videos of 2000+ scoring towers, that information alone would not necessarily help you on your way to building yours. Richard Feynman spoke a great deal about the perils of "cargo cult" science (Cargo Cults are fascinating, you should google it if you've never heard the term!) and it boils down to this: imitation, without a deeper and broader understanding of what exactly you're imitating, will never produce the same results.