Elevated Bridge B/C

[gandhiji]

has anyone gotten an efficiency over 1,500 yet?? just wondering...

[croman74]

I believe a couple of kids on this site have gotten over that, or very close. I haven't, however.

[frontlineballer1]

I finally broke 1,700 for C division. I had built 2 bridges for my state tournament which was yesterday. i submitted one of them and it picked up a lot of weight in the storage room. but today i took my extra bridge and i baked which lowered the weight to about 7.9 grams. and it held up 13.53 Kg. which gives it a total efficiency of of about 1712. I just wish i could go to Nats. it would be extremely nice. and im not gunna share my design entirely. i posted a picture of it on this site for 24Hrs. so those of you that saw it kudos.
Cheers gents.

I think that answers your question. Also little helper the lightest legs you can get away with is light-medium density 1/8" x 1/8" balsa. only 2 pieces on each side. then a Z brace of 1/16" x 1/16" balsa they seem very frail but as long as the balsa is the right density it will have no problems.

Also something ot add my team was 27 points away from making nats so i was very close. Basically had we competed in It's about time we wouldve made nats.

Best of luck to all of you.
Cheers

[sunvista]

Sorry to hear you can not go to nationals.

what kind of truss design you had?

[frontlineballer1]

I will post a picture in a few months but lets just say it was absolutely epic with a bunch of lamanating. however you spell that word.

[gandhiji]

yay i finally finished my bridge...it weighs 11.2 grams and is made completely out of balsa...i hope it does well

[VishaalK]

Is it better to Z brace the bridge or to cross brace it? I'm currently debating this and if it is cross bracing, how would you go about doing it?

[frontlineballer1]

Personally im a fan of the Z brace. its saves wood and an X brace just truly isnt necessary assuming your bridge design is a good one.

[gandhiji]

has anyone tried loading there bridges on the bottom chord instead of the top? if u have, is it better or worse than loading on the top?

[Mike4192]

I just got back from NJ states, my bridge (one of the last to go) had the highest ratio out of all, but was quite literally 1 mm out of spec, so I didn't get anything.

EDIT- Meh, looking back at it, I don't care anymore, I just know my bridge outperformed every other in the state from the ratios I saw, 1mm out of spec or not. Although the judges may have been incompetent (one asked during impound whether the two numbers they get had to be multiplied or divided by each other), they were right, I was 1mm out of spec, even though I could have just slipped a thin piece of balsa under one of my bridges legs and won. I'm unofficially the champ of elevated bridge in NJ, good enough for me.