I was a little curious about popsicle stick bridges after writing about one last week. A young reader asked me if I had any specs (strength, etc) for popsicle sticks. I had a reference like that once but it was in a book, in a lab, that I no longer have access to. Can't recall the title...sorry. Although, creating a table of specifications would be an interesting activity for students to do before starting the actual building.
I went to Google to see if I could find some interesting sites that might be useful to young builders. Here are a couple that I found after an evening of searching.
I like this site, Model Bridge Design, put up by a young man named Garrett Boon. He has been building bridges for seven years and participated in many contests. He is a bit of an entrepreneur and is selling some of his more successful designs. But, I think you can get plenty of ideas and good advice from browsing his articles without buying the plans. Don't forget to check out his link page.
Here is a video podcast by Bre Pettis from Make magazine demonstrating how to build a popsicle bridge and some footage of a competition he set up. (I wish Bre Pettis was my neighbor.) This could be a fun way to introduce the topic. Notice they are testing the bridge by standing on it. Also notice the wide variety of shapes and sizes. I'd suggest some basic parameters for any competition including:
- Length of bridge
- Judged by weight held? Weight of bridge? Ration of the two?
- Does there have to be a road bed and if so, does a model car have to be able to move across it.
Without any guidelines, I've seen students build solid blocks made of sticks and glue that were immensely strong, but used little in the way of design.
I'd also recommend coming up with a method other than standing on the bridge. It's hard to adequately explain to your principal or to a parent how a child sprained an ankle in your tech class as part of their assignment. For large bridges, we used cheap weight lifting plates I bought at a sporting goods store.
I got over 40,000 hits using the search term, "popsicle stick bridge." A lot of the sites were either too technical or relied on a lot of written description with no pictures or diagrams. If you are getting ready to do a project like this in your classroom, there are lots of resources available. Just be ready to sift through to find the good ones. If anybody has a site related to this topic they'd like to reccomend, please add it to the comments.
[Image captured at Model Bridge Design:http://www.garrettsbridges.com/photos/popsicle-bridges/popsicle-bridge-3/]