Elevated Bridge B/C

[Jim_R]

Discussion for Elevated Bridge B/C.

Elevated Bridge Wiki
The Best of 2009#Elevated_Bridge_B Wiki
Elevated Bridge Image Gallery
2009 Thread

[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?

[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! i think im going to go hunt down my coaches for one...

[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.

[Aia]

I uploaded the first ten bridges I built in the season:

http://gallery.scioly.org/categories.php?cat_id=52

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

[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!

[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.

[Aia]

Here is a slideshow of the first 35 bridges I tested last season:

http://www.youtube.com/watch?v=MOTnMAtg7LM

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.

[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!

[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.

[sewforlife]

can anyone help me with setting up a testing rig? The testing set-up for Elevated Bridge should be the same as the set-up for non-elevated bridges?

[andrewwski]

Pretty much. At a competition, expect a base with markings for where to put the bridge and a hole down the center for dropping the bucket. To test, all you really need are two desks or tables of the same height to put the bridge on.

[sewforlife]

yeah. I have those. and now all I need is a right-sized block of wood to drill a hole in with a washer and some s-hooks. thanks!

[Aia]

I finally finished updating all my photos to the image gallery:

http://gallery.scioly.org/categories.php?cat_id=52

Enjoy!

[JimY]

Aia, which one of them did you use at nats?