Stan’s Obligatory Blog

Happy Halloween

3/11/2008

Night hiking in Griffith Park

Filed under: — stan @ 11:18 pm

This evening, I did a night hike in Griffith Park in Los Angeles. Since Gene’s accident last November, I’ve been trying to do a bit more weight-bearing exercise. And besides, this is a good excuse to get out of the house.

I joined a hiking club that I found through meetup.com. We met at the parking lot by the merry-go-round, and headed up the hill. When we started out, it was dusk, but there was still a fair bit of light. But it got darker as we went up. We saw a nice sunset over the Griffith Park Observatory on the way up.

By the time we got to the top, it was pretty dark, but that was all right. We took in the view of city lights all around us, and then we headed down. We had to be bit careful on the way down, since it was hard to see, but most of the hike was on dirt fire roads, so it wasn’t particularly tricky. And overall, it was a fun time.

An exercise in real-world engineering geekdom

Filed under: — stan @ 9:07 pm

It’s springtime, and time for the ME72 Engineering Contest. This year’s contest was a departure from the past ones I’ve been to. For the first time I remember, it was held outside, and this time, the contest was to build a machine to launch a small object across the field. They had a horizontal rope 30m from the launch pads, and 5m high. The machines had to send their payload over the rope. Beyond that, the longest distance would win.

The machines ran two at a time against each other. So the winner each time was the machine that threw its payload the farthest in that round. There were basically two types of machines used. Most were catapults of some sort, using rubber tubing as a large rubber band to store energy for the launch. They were basically large slingshots. Most of these machines used a small electric motor to stretch the rubber bands. Some had very short launching tracks to fit within the space constraints. Some had longer tracks that started out vertical and had to pivot downward to the proper launching angle. The machines had to fit within the horizontal area of the launch pads.

The second type of machine was a variation on a trebuchet. There were two of them in the contest, and they did very well. One of them was finally eliminated in a later round when its throwing arm buckled during a launch. They repaired it, but it just wasn’t the same, and it ended up losing.

In the end, it came down to Team Savage Rabbit against T.T.B. (Team To Beat). A catapult against a trebuchet. Both machines were very dependable, but in the final contest, the catapult shot its projectile just a little bit farther. The winning margin was only a few feet.

Anyway, it was a fun afternoon.

Powered by WordPress