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Re: Elevated Bridge B/C

Posted: March 22nd, 2009, 11:24 am
by 11madmic
Our middle schoolers also have a bridge in the 1800 eff.

Re: Elevated Bridge B/C

Posted: March 23rd, 2009, 5:08 pm
by croman74
That's a pretty high efficiency. I think that now that I have a little time before states, I going to try out an A-frame design.

Re: Elevated Bridge B/C

Posted: March 23rd, 2009, 7:18 pm
by smartkid222
this is unrelated to bridge building, but what would be the strongest glue when weight wouldn't matter. I"m just wondering. Would it be gorila glue?

Re: Elevated Bridge B/C

Posted: March 23rd, 2009, 7:42 pm
by andrewwski
Depends on the material you're gluing. I'd say any glue is stronger than the balsa itself - so it'd be hard to tell.

For harder woods, I'd be inclined to think wood glues would be the strongest. Although polyurethane (Gorilla) glues are pretty strong for that use as well.

I remember reading an article in a magazine once where different glues were put to the test in different grain-type joints. I'll have to see if I can find it.

Re: Elevated Bridge B/C

Posted: March 23rd, 2009, 7:51 pm
by smartkid222
what about for metals or plastics? ( i said this was unrealted to bridge)

Re: Elevated Bridge B/C

Posted: March 23rd, 2009, 8:43 pm
by andrewwski
See, that's where it depends on the materials being bonded. For plastics you're probably going to be best with some kind of epoxy. CA's will also work well. So will polyurethanes. White glues and wood glues won't.

For metal, you may get have success with some kind of epoxy. CA's will only give limited success, and white glues won't work at all. Don't know about polyurethane glues, but I doubt it'll be wonderful. Metals are hard to bond. Certain types of metals can be soldered.

Re: Elevated Bridge B/C

Posted: March 24th, 2009, 2:12 pm
by Jo_squirrel
Congrats to those who are going to Nationals!!
I bet your bridges are incredible. I hate that I realized a design flaw much too late to play around with it, and I've been avoiding my building stuff because I don't want to be all regretful (and also, we're moving house soon and my mom'd hate it if she saw me making a mess for no reason).

Re: Elevated Bridge B/C

Posted: March 24th, 2009, 2:18 pm
by jazzy009
i think minnesota fails a bridge building...
we got 1st with an 863ish eff. at state.
fail.

Re: Elevated Bridge B/C

Posted: March 24th, 2009, 5:26 pm
by NamG
andrewwski wrote:See, that's where it depends on the materials being bonded. For plastics you're probably going to be best with some kind of epoxy. CA's will also work well. So will polyurethanes. White glues and wood glues won't.

For metal, you may get have success with some kind of epoxy. CA's will only give limited success, and white glues won't work at all. Don't know about polyurethane glues, but I doubt it'll be wonderful. Metals are hard to bond. Certain types of metals can be soldered.
Check out http://www.thistothat.com

Re: Elevated Bridge B/C

Posted: March 24th, 2009, 5:40 pm
by nejanimb
jazzy009 wrote:i think minnesota fails a bridge building...
we got 1st with an 863ish eff. at state.
fail.
That's not bad at all! Congrats on gold. But, really, I think that most teams in the country would still be pretty pleased with an 863.