I’ve been itching to try out Ponoko for a long time. The idea of any old person being able to turn vector shapes into real objects is a spectacularly empowering one. After seeing some of Gregg Fleishman’s incredible work, I decided I had to start experimenting.
I wasn’t sure what to start with though – something too easy and you won’t learn anything about the nature of the medium - cutting width, material tolerances, that sort of thing. On the other hand, though, if you reach too far you won’t end up learning anything either – if you try to design an ornate interlocking castle without some appreciation of how things actually work you’ll end up with an elaborate mess. So I tried to strike a balance somewhere in the middle. I tried to design a remote control car with rack-and-pinion steering (though I didn’t know what that was until I looked it up either)
The first thing to consider with laser cutting things is that you only get flat sheets and holes carved into a single dimension – so when you have a mechanism where two parts have to be hinged at right angles, you’ll need to make that hinge happen at right angles to both of those surfaces. I’m not an engineer so it’s a novel experience trying to figure these things out. Once I had an overall idea of how the car was going to fit toegether, I could start doing more precise drawing.
Vector graphics applications are a wonderful thing. Using Illustrator, I was able to draw the shapes I wanted, measure them up against one another and fit them on to the specified sizes. I was hoping to keep the thing as small as possible, so it’s on an 18×18cm board with a lot of room left over! I used some of that room to try and figure out how a bearing assembly might work made out of cut board.
Next I had to wait. Ponoko say they’ll clear their queue of designs inside 28 days, and mine was done within 11 so I was pretty happy with that.
Then, it arrived! Actually I picked it up but it was fantastic to see. Unfortunately at the time of first unwrapping the sheet with all 114(!) parts laid out together I didn’t have a camera with me, so that moment is lost to history. Once I did manage to get everything assembled, though, it looked like this:
Unfortunately once it was assembled, it turned out that the motors I had planned to use were too big, and the drive axle for the rear wheels was too short. The bearings worked out better than expected, though, and at about a third of a millimetre, the beam width will be easy to account for in future designs. I’m looking forward to prototype #2! Between this and the Arduino micro-controller, I think it’ll be possible to do some pretty fun stuff.