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Elevated Bridge B/C

Posted: June 9th, 2009, 9:05 pm
by Jim_R
Discussion for Elevated Bridge B/C.

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Re: Elevated Bridge B/C

Posted: August 2nd, 2009, 10:32 pm
by nejanimb
Anyone started with anything yet? We put together one experimental design, using last year's rules just so we could test the principle of it... Unfortunately, we don't have any testing equipment, so we're stuck with a bridge and no way to test it! Oh well.

What do people think?

Re: Elevated Bridge B/C

Posted: August 3rd, 2009, 6:20 am
by soobsession
ugh...i have to build a bridge over the summer that is "unelevated" for tryout purposes when clearly this year the event is elevated bridge...worse yet, we cant weigh our bridges cuz we cant find ourselves a scale cuz my idiot school wont lend us one! :evil: i think im going to go hunt down my coaches for one...

Re: Elevated Bridge B/C

Posted: August 3rd, 2009, 7:50 pm
by Aia
I am in the process of uploading most of my bridges to the online image gallery. I'll probably upload 37 or 38 of the 42 that I built during the 2009 season. In the information section, I also plan to post the bridge mass, weight held, efficiency, and any other relevant information. When more photos are uploaded, I'll post here to let everyone know.

Re: Elevated Bridge B/C

Posted: August 4th, 2009, 3:29 pm
by Aia
I uploaded the first ten bridges I built in the season:

I'm in the process of adding descriptions to each, but feel free to ask questions.

Re: Elevated Bridge B/C

Posted: August 4th, 2009, 7:46 pm
by nejanimb
Thanks Aia! Those are great. Some very interesting designs! I look forward to seeing the rest, though I hope you don't share the final tricks you used at nationals ;-).

Several of my designs are in the gallery as well. I show my upside-down suspension design, as well as the components of the nationals bridge.

As far as new ideas - I've been interested recently in trying some radical changes. Mostly, I've worked with A-style designs, and those have worked well, but I want to experiment with branching off. I am interested in trying something like the bridge BalsaMan posted, with a full horizontal compression at the top, or something like the Troy nationals design, though I still can't quite figure out how they got that to work loading on tension. Also, I want to try building my own I-beams for compressions - I don't like straight laminations, but I think that kind be interesting. I'm thinking of sandwiching a 1/16th square piece between two pieces of 1/8 by 1/16 with the square piece centered on the others, so it creates that kind of "I" shape. Another thought - I've never been convinced that the main tension of the bridge can be held by horizontal pieces (as in the Indiana B Nationals winner design), and I like having the legs closer to vertical, though I might try it anyways.

New season - so many options and opportunities!

Re: Elevated Bridge B/C

Posted: August 4th, 2009, 7:52 pm
by andrewwski
I tried making a few I-beams last year but I found the weight of the glue was pretty significant. Applying glue along the length, twice, added significant weight, even when I (as always) used the minimal amount of glue. I was using CA, however, which can be quite heavy compared to some glues.

I'd be interested to see if I-beams can be used effectively - if they can be made light enough to make them stronger than an equally weighted piece of thicker or denser balsa.

I'm sure it can be done, but I didn't have enough time last year. Would be interested to see others' findings.

Re: Elevated Bridge B/C

Posted: August 9th, 2009, 9:48 am
by Aia
Here is a slideshow of the first 35 bridges I tested last season:

I'm still working on getting all of these images uploaded to the gallery, as well as writing descriptions for each. However, I thought the slideshow was great way to show a lot of bridges in a short time period. Moreover, I hope these images can provide some fresh ideas for those competing in the 2010 Elevated Bridge season.

Special thanks to nejanimb for the music. ;)

Re: Elevated Bridge B/C

Posted: August 9th, 2009, 9:58 am
by croman74
Thanks for that and the pictures Aia. I know those are definitely going to help a lot of people, myself included. I can't wait for the rules this year!

Re: Elevated Bridge B/C

Posted: August 9th, 2009, 8:21 pm
by nejanimb
I loved the music. And so perfectly timed, too!

But oh yeah, the bridges were cool too. Thanks very much for sharing! One of my goals for this coming season is to document my bridges as thoroughly as you have as I go along.