Aia wrote:YES!!!
Omg, I just had my best Elevated Bridge score ever! My bridge held the whole weight despite the huge mass gain from the humidity! YAY!
Aia, that great to hear- well done, sir! That must have felt great as the last couple kilos of sand went in. 1500+ is a serious accomplishment w/ this year’s specs (B & C); heck, getting >1200.is really good (both a smart design and good execution needed)
quickestwinne wrote:top one for C was about 2400 and top one for b was about 2100.
I have seen the top one for C. It's at my house.
The one that got 2nd in B is also there-it got around 2000.
Top scores are not a total surprise. As dholdgreve says, truely amazing; a handfull of folk DO seem to come up with the amazing every year. I’m
really curious about how the scores came out for both C & B below the top 2 or 3– at least the top 10 or so. Hopefully someone can provide that insight (rjm?) - a little more complete picture of how the building skills vs geometry tradeoffs played out. Still guessing that B average in this range will be higher than C, but beginning to think I could well be be wrong. I
really hope we’ll see some pictures posted to the Image Gallery of some of the successful designs.
A few observations from watching the webcast (realizing their selection may not have been representative of the field)-
It
did seem like there were a lot of premature failures – like earlier than expected. High humidity, and the consequences of that certainly was a factor.
I was surprised at the number of arches – and am very curious if any made top 10. I and some others had the sense that there were real limitations on how competitive an arch could be.
Saw a few tip-over failures, which I assume were straight-sided configurations. My guess is that nobody with the sides leaned in a bit ran into that.
A few comments on the two bridges I was involved with – the Colorado ones; Poudre in C, Blevins in B; both being based on the design of my son’s State bridge. In both cases, very little time between State & Nats to build a new design. Poudre’s was essentially the same design, with laminated balsa legs replacing basswood ones (light core w/ angle iron 1/64th lamination) – got to watch it go on the webcast. Weighed in from the report I got at 9.85g, carried 12.59kg; 1304; 10th place. I think I know why it didn’t make it all the way to 15 (I’ll have to verify this with them when they get back) – it looked like there were no tension control strips at the bottom of the legs. With a 3/32nds lean-in on the sides, there is a slight separating force at the leg ends, not much, but enough to need a little piece joining/holding leg ends together.
Blevins’ was the same design modified to B dimensions, w/ the same laminated leg construction; weighed in at 7.50g, carried 9.63kg, 1284, don’t yet know placing. Their run wasn’t webcast, but got a live cell phone report. Failure appeared to be where we expected; lower leg section. Because of the higher bottom clearance required in B, the exposed column lengths in the legs were longer than in the C bridge. Calculated load it should have carried (from my son’s bridge) was about 90% of what it would have seen at 15kg loading. That we had a leg failure around 50%, probably a combination of variation in wood and glueing of laminations, and humidity. With higher density wood seeing a greater dimensional change than lighter wood, the laminated leg construction + humidity may well have meant a slight curve instead of being straight.
Congratulations to all that did well; the winners, the medalists, those that came close. Looking forward to hearing more on exactly what happened at Nats, and how the rules will be tweaked for next year.........