February 07, 2007

Engineering

I’m taking an engineering class this year and of course, I’m lovin’ it (McDonald’s pun totally intended). So far we’ve made mousetrap powered catapult cars and little wooden bridges, not to mention a lot of animations and computer models. Now we’re on to our latest and greatest project, the legendary Wooden Toy Project! Basically, our teacher showed us all a book full of the most complicated looking little wooden toys ever and said “Draft. Animate. Build. Pass.” So. . . . that was that! We all dug around in the little book to find toys to build. There were different strategies people employed when choosing. Some went with the “I’m going to pick the easiest one in there and get done in a week” method. Me? Nope. Some went with the “I’ll build one that somebody else is building so that we can help each other” method. Me? Nope. Some went with the “I don’t really care, just give me one” method. Me? Nope. Some went with the “Let’s find the most complicated little puzzle in the book with the most curves that will be impossible to constrain on the computer and even more impossible to build and has the least satisfying result!” method. Me? You betcha! *Sigh*

I chose a wooden lock/key/tumbler toy. I began by drafting it in AutoDesk Inventor (computer program) and then assembling it all into a pretty 3D model. Then I had to actually tell the computer the physics behind how the pieces moved and clicked around so that you could actually turn the key on the computer and the deadbolt piece would move. I’ve never had to do anything more frustrating in my life. Ever.

The computers in our CAD lab are beefy and are very good. I’ve never been able to crash one. That being said, I crashed my computer 13 times trying to constrain those pieces together so that they’d move. It was hell, and towards the end I actually started slamming my keyboard against the desk and contemplating strangling myself with the mouse cord. In the end I gave up, switched programs to AutoDesk Viz, and made an animation. SO MUCH EASIER! When I get a chance I’ll upload the animation I made.

After that was the building stage. Not a lot to talk about here. I spent about 2 weeks with a band saw and a belt sander getting the pieces right. I’d have to say that the hardest piece was the bit that slides when you turn the key. The one in the final toy is the 4th one I made. The other 3 had. . . issues. I was anticipating that the building stage would take about 5 weeks, but to my surprise and a brilliant stroke of luck, I was able to cut it down to 2. The stroke of luck came when it came time to cut a notch in the sliding piece such that when the key turned CW, it would slide, and when turned CCW, it would slide back. I was expecting to have to cut multiple notches on multiple sliding pieces until I got it just right, but it turned out that the rough notch I cut the very first time worked perfectly! YAY! After that I just cut out the tumbler (easy), sanded everything so that it’d be nice and pretty, assembled it, and mounted it to a base with dowels. Ta-Da! One lock and key wooden toy! It’s surprisingly fun to just turn the key back and forth and watch the sliding piece move in and out.





It may not look like much, but a lot of work went into this thing and I’m very proud of it. I’ve never really made something small and mechanical out of wood by myself, most of my wood experience is large scale construction and I work with my dad. This little guy is kinda my own baby. I’m quite fond of it.