BuildingFriend wrote:Balsa Man, let's do some reanalysis on the bonus.
You claim the bonus can in fact lead to a higher score, I disagree.
Here are a few things to consider:
1. With the bonus, you are changing a square base from 16 cm, to 22, cm an 8 cm increase. -> more use in leg wood
2. Next, with the legs farther apart, more bracing wood is required, as well as stronger bracing wood
3. The more angled tower, leads to less strength among the legs itself.
4. all of these disadvantages are in exchange for 2000 grams extra to your score
5. If you are just going for a 2000 scoring tower, you would have to be at 8.5 with the bonus, 7.5 without, to make all these changes (steps 1, 2, 3) you would need according to my calculations more than a gram to make it work (hold all)
These are my insights and my ideas, no means to argue
What are your thoughts?
Thanks for insights
Balsa Man, let's do some reanalysis on the bonus.
Cool, let's
You claim the bonus can in fact lead to a higher score, I disagree.
Here are a few things to consider:
1. With the bonus, you are changing a square base from 16 cm, to 22, cm an 8 cm increase. -> more use in leg wood.
Yes, but very little; about 1cm/leg = just under 4cm more, and density the same
2. Next, with the legs farther apart, more bracing wood is required, as well as stronger bracing wood
Yes, more wood (longer ladders and Xs), but no, not really, on “stronger” (as in higher density) bracing required; very low density works in both cases- for ladders above the bottom one, 0.7gr/36 (1/8”), lowest density you’re going to find is more than strong enough.
3. The more angled tower, leads to less strength among the legs itself.
I think you’re trying to say, more angle = higher forces at a given load; however, that increase is very small (<0.05kg, at a 15kg tower load)
4. all of these disadvantages are in exchange for 2000 grams extra to your score
The noted ‘disadvantages’ are small, and the +2kg is large
5. If you are just going for a 2000 scoring tower, you would have to be at 8.5 with the bonus, 7.5 without, to make all these changes (steps 1, 2, 3) you would need according to my calculations more than a gram to make it work (hold all)
That’s not what my calcs say.
These are my insights and my ideas, no means to argue
No problem- this kind of argument/dialog, and thinking about all the issues in play to analyze this, is a good thing; science and engineering at work.
What are your thoughts?
Thanks for insights
The analysis I ran looks at a C-tower, legs at 1/8”,1.4gr/36” legs, braced at 1/5 interval, ladders (at 1/8”, 0.75gr/36”) and Xs (1/64 x 1/16 at 0.00224 gr/cm) bracing.
For tower meeting the bonus
Legs- 245.2cm, weight 3.75gr
Ladders- 225.5cm, weight 1.85gr
Xs- 802cm, weight 1.8gr
Glue, 1gr
Total = 8.39gr; score if 15kg held =2026.1; score if 14kg held =1906.9
For tower not meeting the bonus
Legs- 242.64cm, weight 3.71gr
Ladders- 165.10cm, weight 1.35gr
Xs- 641.6cm, weight 1.44gr
Glue, 1gr
Total = 7.50gr; score if 15kg held = 2000.7; score if 14kg held =1867.3
Close, yeah, but the bonus tower wins, and as you come down from full load held, the winning margin increases. This doesn’t surprise me, because over the years, in wood structures, and other building events, every time the rule makers have included a bonus it has been very carefully designed to pay off. There’s a lot of careful thought that goes into coming up with and defining bonuses to work this way. The analysis above is….conservative a) because using 0.75gr/36” to calculate for ladders, but 0.7gr/36” is strong enough for both versions, and b) the lighter the tower, the bigger the difference/payoff. For folk shooting for >2000, the bonus is even more important. 
