Elevated Bridge B/C

[sewforlife]

what page is the stuff you said about the correct jig?

[nejanimb]

I have to disagree with Balsa Man on this one. Although a well built jig obviously cannot hurt, I think it'd be misleading to say that it is the only way to build bridges competitive at the 1200+ ranges. I think that, with bridges, jigs don't make sense in a lot of ways. With Towers, jigs would help a lot, as the whole structure had an entirely different dimension - usually 4 symmetric sides. With bridges though, I know the strategy that a lot of people take (myself included) is to build just two symmetric sides of the bridge, and then connect them in an entirely different way. Because of this, I think that those two sides can be built fairly easily on a 2d surface, such as building on top of a schematic or drawn template. Where the jig becomes more useful would probably be with connecting the two sides - and even still this can be done accurately without a jig.

Of course, these things aren't actual negatives of making a jig, just my input that I know that good construction can be done without one. The problem though is that using a jig (typically) allows for much less flexibility and opportunity for change in the design since it requires a major reworking of the jig itself. I think to suggest that teams should focus on getting a good jig built would be misleading - it's my opinion that keeping the door wide open to playing with even the most minute details of the design is more valuable, and that that will overall lead to greater success.

That said... I've wished all year that we had a good jig to work with. Though I'm overall glad we've spent the time building and testing bridges instead and not having one has given us the opportunity to tweak the design (which we're still doing even this late in the season on a small scale, it definitely would be a more convenient way to build.

One thing we have done as far as trying to keep the bridge as uniform as possible is to mass every individual piece. Previously, we would mass each full stick of balsa, and cut our members from pieces that had the same mass. However, we found that there was too much variation even within each stick, so we've been cutting every piece and making sure that they are actually the same mass before we put them in the bridge. It's a painstaking process, especially when our tolerance is 5 thousandths of a gram, but I think it does actually help.

On a different note but still addressing Balsa Man's post, I'm interested to see that you had more success using sides that were angled in. I've always been under the impression that doing so just makes the force that your main sides have to undergo even greater and it introduces a new force that the connecting pieces must take. Balsa Man, what made you decide to ultimately do this? And, to everyone else, have other people seen similarly positive results from this type of construction?

[Balsa Man]

what page is the stuff you said about the correct jig?

It was Dec 10th; not sure of page. I was able to get to it by using the "sort by" button at the bottom - sort by author.

Len Joeris
Fort Collins, CO

[croman74]

I believe that it was on page 25.
When I said that I don't like working with a partner, I didn't mean to imply that good bridges can't be built by 2 people. Take Len Joeris's son for example; there's a strong bridge build by 2 partners. However, I believe that it would be better to have those 2 people work on separate designs, sort of a "divide and conquer". I don't mean to offend anybody in any way, I'm just giving my 2 cents.

[sewforlife]

thanks. and thanks for the advice again

[sewforlife]

I believe that it was on page 25.
When I said that I don't like working with a partner, I didn't mean to imply that good bridges can't be built by 2 people. Take Len Joeris's son for example; there's a strong bridge build by 2 partners. However, I believe that it would be better to have those 2 people work on separate designs, sort of a "divide and conquer". I don't mean to offend anybody in any way, I'm just giving my 2 cents.

yep. same for me. testing the two bridges of different designs can be helpful with time management and such

[nejanimb]

I definitely agree with the strategy of having people build different designs. For the beginning of this year, we had a veritable army of 6 people building all sorts of bridge designs, and the final one we've been working with has been the product of really everyone's work. It's great to work with a team, even for an event that seems like it might work best individually.

[croman74]

How did that bridge do? And did you combine different ideas for the final bridge, or was there one design that was doing better?

[nejanimb]

I don't feel comfortable revealing actual scores yet, since we still have a competition (and hopefully two) left to go this year. I'll post results when scores finally are settled for the season. But, I will say that it's at least over 1,000.

The final design has definitely been a cooperative effort. For a few months we couldn't get much above 500. Then, we had one design do well, and then brought in a few elements from the other designs, and were able to more than double our score in the span of 3 weeks. Building all together definitely helped - even if not everyone's bridge could tell us the way to make it work, every one mattered because it taught us what sorts of things didn't work, which is often just as important. Like I said, even now, we're still changing things about our bridge, trying to tweak and perfect the design.

[hbk.showstopper]

I definitely agree with the strategy of having people build different
designs. For the beginning of this year, we had a veritable army of 6
people building all sorts of bridge designs, and the final one we've
been working with has been the product of really everyone's work. It's
great to work with a team, even for an event that seems like it might
work best individually.

are all of those people who were working on the different bridges on the same team....or like if you combined how did you select who would go to nationals and who wouldn't?