Efficiencies

[lllazar]

Not that i can think off...it would just add more weight.

[Littleboy]

It would add weight and make it less stable

[jander14indoor]

is there any reason to build the tower higher than required?

Yes, to make DARN sure you are not disqualified. Never push it so close you risk disqualification. But only by 1-2 mm. Any more IS just excess weight as others have stated.

Jeff Anderson
Livonia, MI

[iYOA]

how good is a 19.5? in your opinion, what ratios would you need to get top 5 at nats?

[Snarf]

I ran this event yesterday at an invitational in the Kansas City area. From memory, here are the top efficiencies for each division:

Div B.:
1. 26.5
2. 23.4
3. ~19.3
4. ~13

Div C.:
1. ~14.6 (but it got Tier 2'd due to being slightly too wide at the top)
2. 11.7
3. ~10.5

I don't think these represent nationally competitive scores, but they come from schools that usually place in the top half at nationals.

[nejanimb]

how good is a 19.5? in your opinion, what ratios would you need to get top 5 at nats?

19.5 is a good start. My guess is that you'll need something into the 50s (with the new scoring) to be in the top 5 nationally. Wouldn't be all that surprising to me if the winner was into the 60s or even 70.

[JimY]

In general, I think the top scores for both divisions at nationals will be about the same, with B maybe a tad higher, and that a score of greater than about 50 will be needed to make the podium. I have no idea on how to get to greater than 60, but I expect one or two teams will figure out how to get there. 70 seems on the preposterous side, as this is 3.21 grams for a 50 cm tall structure that doesn't break at 15 kg. I'd like to see that tower, either B or C division.

[rjm]

At Nationals in 2008, the B division tower rules were almost identical to the current B rules except for the scoring formula. The top tower had a mass of 4.3 g, held 13.700 Kg, had an efficiency of 3186, and under the new scoring would have a score of 43.649 million grams. The second place tower had a mass of 4.82 g, held 15.000 Kg, had an efficiency of 3112, and this year would have a score of 46.680 million grams. The third place tower had a mass of 5.18 g, held 14.560 Kg, had an efficiency of 2811, and this year would have a score of 40.925 million grams. Efficiencies dropped considerably after these. These were remarkably good towers and the rules aren't much different, so I think that scores above 50 million grams will be rare.

I can't find my scores for Nationals in 2006. If I come across them, I post the top ones; maybe someone else on this board can find a copy. The new C division rules are virtually the same as that year, except for the scoring, so I suspect scores derived from 2006 results will be a decent guide to expectations for this year.

Really, the only differences are that wood of any cross section may now be used, the rule prohibiting touching of the chain against the tower during loading was omitted, and the rule prohibiting sagging of the tower into the opening during loading was omitted (these are only prohibited as initial conditions, I have no idea why those rules were dropped). It would take a dramatic breakthrough to get scores around 60 million grams.

Bob Monetza
Grand Haven, MI

[JimY]

As for C division scores from the 2006 national tourney, this is what happened after having this event for 2 previous seasons:
1st place 4.18 g - loaded to 13.625 kg --> old score was 3260 and new score would be 44.4
2nd place 5.42 g - loaded to 15 kg --> old score was 2767 and new score would be 41.5
3rd place 4.53 g - loaded to 12.22 kg --> old score was 2698 and new score would be 33.0
4th place 5.44 g - loaded to 13.745 kg --> old score was 2527 and new score would be 34.7
5th place 6.19 g - loaded to 15 kg --> old score was 2423 and new score would be 36.3
6th place 6.05 g - loaded to 14.58 kg --> old score was 2410 and new score would be 35.1
7th place 6.56 g - loaded to 15 kg --> old score was 2287 and new score would be 34.3
8th place 6.29 g - loaded to 13.935 kg --> old score was 2215 and new score would be 30.9
9th place 5.14 g - loaded to 10.895 kg --> old score was 2120 and new score would be 23.1
10th place 6.47 g - loaded to 13.495 kg --> old score was 2086 and new score would be 28.1

I also computed new scores for places 11-30. The interesting thing is that after looking at 1-30 with the new system, the top 10 stayed the same, and only their order was changed. The third place tower from 2006 ended up in 7th with the new system and is the one that changed the most places in the top 10. In places 11-30 from 2006, the 19th and 21st place finishers would have ended much further down under the new scoring system, probably 2/3 to 3/4 of the way down the list. They were light towers that failed at low loads (4.92 grams and 6.815 kg for one and 3.83g and 5.065 kg for the other).

So, there you have it from 5 seasons ago. A grand total of 2 C division towers would have scores above 40 with the new formula. So, based on this, I'm changing my previous position and am agreeing with rjm in that anything above 50 will be breakout new technology. So, scores above 40 will likely earn medals in Wisconsin next May for both B and C.

[lllazar]

Wow, 22.5 isn't too shabby by the looks of those scores.

[paronomasia]

So our tower doesn't hold more than 1 kg... efficiency less than 1 fail

[Wolves]

[lllazar]

Uhh, error in the image?

[sciolyswizzle16]

What are some of the best efficiencies you guys are getting?
And if our base keeps breaking, what would be a good way to fix it?

[AlphaTauri]

The base of the tower or the test base that it rests on?