Have Glue Gun, Will Travel (AKA Spaghetti bridge, part 2)

After our rather demoralizing defeat at the hands of the kittens, it took us a week or so so get back to bridge building. When we did, we used the same template (hence the same picture above. It's not your imagination.) The bridge had to be totally rebuilt. There was no salvaging the pieces of the prior bridge.



Here is the finished bridge. We had some fun with it before we tested its strength. After all, we test to the breaking point. So once the bridge is "tested" it's no longer any good for playing around with. The floor of the bridge is linguine noodles. We removed the linguine for the testing. In the meantime, it took a bit of time for this traffic jam to clear up.

Finally the test. We hung a bag on the bottom of the bridge, supported by an unbent paperclip and a craft stick. We weighed these. They would be part of our final test weight after all. Then we began to fill the bag with quarters. I figured that it would be easy to measure quarters. You can just weigh one and then multiply by the number of quarters in the bag, right? Just for comparison, we broke one strand of spaghetti prior to building the bridge. It took 32 pennies to break one piece of spaghetti. We moved up to quarters because I didn't think I had enough pennies to break the bridge.

 



the wood brace you see is the table brace. It has nothing to do with the bridge. The angle is just weird.

empty bag.

quarters

more quarters...

It turns out, we didn't have enough quarters. We added other change. Nickles. Pennies. Dimes. We had to add a second bag.

We ended up with this bag and a different hook. We unbent the large s-hook I'd created with the paperclip and used an industrial strength hook finally. The bridge broke eventually, but it took a long time, all the change in the house, and finally the matchbox cars.

The test-broken bridge.

This is what it took to break Caleb's spaghetti bridge. The hook on the outisde of the bowl is what we hung everything from. It was just over 8 pounds of stuff.

 

Now, I know that physics classes do this kind of thing all the time, and that there are contests out there for high school classes. I've seen balsa bridges that support 200+lbs of weight. And damn, I'm impressed by those things.

 

But I'm impressed with Caleb's spaghetti bridge and its 8 lb. test weight. The bridge weighed just over an ounce. He designed it. He built it. He tested it. I helped with the weighing and the breaking of the spaghetti and the control of the hot-glue, but I didn't alter his plans. I didn't push my agenda. We talked about architecture. We talked about geometry. We talked about physics. He read some books, and then he designed his bridge. This is Caleb's project. Even when he complained about everything involved, he still took responsibiltiy for it. And now he wants to design more. He wants to build more. He wants to try arches next time. He wants to get over a 10 lb. test on an ounce bridge. 

 

As his teacher, I'm thrilled.

As his mother, I'm proud.

As a driver, I hope that we can find more durable material than spaghetti when he makes his first real bridge.