Scores B/C

[chinesesushi]

Can someone post a picture of one or more of the bridges that medaled this year. The strong rumor is that they are going to go to the elevated bridge for 2016, so copying will not be much of a factor.

yeah it probably will be elevated bridge, but why wouldn't copying be a factor? you just put a regular bridge onto 2 stands basically.

[syo_astro]

If it wasn't being "copied" now, it would be "copied" down the road when the event cycles back (unless...asteroid impact that Chalker foreshadowed O.O). Sharing info here shouldn't be a matter of copying ideas (heck, I've even heard it being called "people getting arrogant", which I also find ridiculous), it should be a matter of learning. Even putting up the pics can still be a challenge what with the possibility of different density members being used.

[iwonder]

Honestly, a lot of the work that goes into design here isn't just a picture and some braces. You've got densities and construction techniques and all those little details about how you treat your bridge that make a big difference in the score.

Pictures are entirely your choice, but I would highly doubt someone is going to be able to build a 2000+ bridge simply by looking at a picture. And even if they did, just more incentive to improve your stuff and beat them again, right?

[retired1]

Answers to comments:
I am in awe of the bridges with such high score. The best we could get was 2500 and we were still making changes. For balsa, we tried everything from 4 # to 12#. We also tried different shapes of wood.
I seriously doubt if you could just put this bridge design on two posts if you look at the height restrictions of the last elevated bridge contest.
That effects the angles which makes it a totally different structure.
Finally, SO will sell a DVD at inflated prices that will have pictures in it, so what is wrong with some proud team posting their bridge in the current time frame?

[JonB]

4th Place National Bridge (post Nationals)- Boca Raton Community HS. The design had a test efficiency of almost 3000, but we scored 2633 at Nationals.

[someusername]

7th place bridge at nationals (Lincoln Southwest High School, NE)

It weighed 5.15 and held 12.65kg for a score of 2456, though our scores were usually around 2600-2700 with the design

[sjwon3789]

4th Place National Bridge (post Nationals)- Boca Raton Community HS. The design had a test efficiency of almost 3000, but we scored 2633 at Nationals.

What's your tension? Is that balsa or bass? It looks interesting...

[PatrickMcPherson]

7th place bridge at nationals (Lincoln Southwest High School, NE)

It weighed 5.15 and held 12.65kg for a score of 2456, though our scores were usually around 2600-2700 with the design

IMG_1133 (800x600).jpg

Major kudos, I won my state tournament with a score of 2455.4 (albeit that was the heighest efficiency I've achieved, and it wouldn't have scored that exact number at nationals) It's great to see such beautiful bridges from all of you!

[PatrickMcPherson]

4th Place National Bridge (post Nationals)- Boca Raton Community HS. The design had a test efficiency of almost 3000, but we scored 2633 at Nationals.

Your design is the most similar I've seen to mine. I Would guess it's all balsa, and the range of density in your compression and tension members is really cool to see. However, I have never used those long members to connect the tension and compression members together, and I was wondering how significant of a difference they made. Most importantly congratulations on a fourth place finish, you definitely earned it!

[PatrickMcPherson]

Here are the pictures of my two bridges for the NC state tournament the one pictured on the left would have placed 8th at Nationals with a score of 2455 (6.06g 14.88kg held). The one on the right was constructed before and in what was essentially the exact same manner as the one tested. I used all balsa, the tensile members are 1/64 by a 1/4 inch. The compression members' outside pieces are 3/32 by 3/8 the inner members are 1/8 by 1/8. All of the cross-members are 1/16 by 1/16. They're roughly 15 cm tall, and have an outer edge length of 49 cm, with an inner length of 46 cm. (The horizontal cross members are literally the excess tensile members) If you want to know more just ask, I'll speak on anything I know.

[JonB]

4th Place National Bridge (post Nationals)- Boca Raton Community HS. The design had a test efficiency of almost 3000, but we scored 2633 at Nationals.

What's your tension? Is that balsa or bass? It looks interesting...

It is bass and we laser cut it to a specific width (it is dark because of the laser cutting process).

And thanks! The team worked very hard on the design. I am still curious what design places 1-3 were. That is a pretty drastic increase in efficiency up to ~3600.

[someusername]

4th Place National Bridge (post Nationals)- Boca Raton Community HS. The design had a test efficiency of almost 3000, but we scored 2633 at Nationals.

What's your tension? Is that balsa or bass? It looks interesting...

It is bass and we laser cut it to a specific width (it is dark because of the laser cutting process).

And thanks! The team worked very hard on the design. I am still curious what design places 1-3 were. That is a pretty drastic increase in efficiency up to ~3600.

I'm going to assume they were something like yours, only maybe they were half the width and had a useless beam running the length of the bridge to satisfy the 5cm width requirement. That way, you would still retain almost all the strength of the bridge at a lighter weight, assuming it is perfectly balanced.

[retired1]

That is what out teams did. 3/32 main members, 5 cm truncated top, 1/32 x 1/8 tension member. 3/32 feet to 2 1/64 outriggers to get the 5 cm, Used 1/2" spacing. Prone to tip over. Gusset plates on top joints of 1/32. Ran out of time to build and test. Under 4 grams. Got above 2500 and with a couple of changes might have gotten to 3,000. At state, a poor glue joint did in the best ones.
I too would like to see the 1-3 bridges. I am still in awe of those scores.