Monday, July 24, 2006


Bruce Sterling gave an interesting talk at a SIGGRAPH conference in 2004. He described two kinds of human artifacts, blobjects and spimes. Blobjects are simply artifacts that have been designed with modern CAD systems, so their shapes are more curvy and sexy than the same-functioned artifacts of past generations. Examples are the iMac and the new VW beetle.

The spime is a different beast. It is jam-packed full of information technology. It has RFID or Bluetooth to talk to nearby computers (or maybe other spimes). It has GPS so it knows where on Earth it is. It knows how to connect to the Internet. It willingly participates in data mining efforts by Google and other search engines and advertisers. In addition to being designed with a CAD system, it might be manufactured with rapid prototyping techniques such as 3D printers.

Sterling's predictions about the spimes' use of information are cynical. They are programmed by the corporations that built them. They collect consumer demographics information about the people who buy and use them. Their first allegiance is to their manufacturer. They are smart enough that the distinction has teeth - the hand drill I bought at Sears does not change its behavior to act in Sears' best interests rather than mine.

If spimes aren't nanotechnology, why am I writing about them in a nanotech blog? Because they shake loose my thinking about what products could be. I hadn't thought about ANY of this stuff before I read the transcript of Sterling's talk. My cell phone today has way more computing power than the Apollo guidance computer had. When a ballpoint pen has way more computing power than my cell phone has today, of course somebody will program it to do things like this.

Wednesday, July 12, 2006

More hoverboard progress

I made the skirt tighter, and I improved the air seal between the leafblower and the skirt feed. For a couple of reasons, I can't successfully ride on the thing myself.
  • The plywood base isn't wide enough, so it's very hard to balance.
  • The plywood base isn't stiff enough, so it flexes under my weight.
  • The air connections need to be better, the duct tape keeps leaking.
  • It's probably a good idea to strap the leafblower engine down to the plywood permanently - leafblowers are cheap nowadays.
Here is what it can do. With the leafblower engine idling, it can hover its own weight quite nicely, and then I can kick it around a parking lot like a hockey puck sliding over ice. Here's a video of that happening.

To a zeroth-order approximation, there are two kinds of engineering styles, planning and prototyping. A planner tries to think through every possible detail or failure mode first, plans out everything on paper, and only then does he pick up his tools and start building. A prototyper begins with a general idea of his goal, grabs his roll of duct tape, and starts putting together the cheapest, cheesiest possible version that will work. With prototyping I discover principles and failure modes that I might never have found by thinking ahead. Besides, I get to take cool videos sooner than later.

When I was a young child, I was by necessity a planner because I didn't have any stuff to build with. So I'd think about things and imagine things and try to reason through as many implications and ramifications as I could. The balance between planning and prototyping is economical. The cost of prototyping is materials, labor, and the risk of problems that might have been avoided with planning. The cost of planning is time, and the risk of problems that can't be foreseen until you have a working model. Simulation is a half-way approach - a good simulator will alert you to problems you didn't foresee with pure analysis and design, but is cheaper than building a prototype.

But you can't shoot the video until you have the prototype. And the video is very cool.

Saturday, July 08, 2006

Building a hoverboard

I'm going to try to build a hoverboard. Here are some videos of people building and playing with hoverboards:
  • One
  • Two
  • Long and detailed with info about design principles
  • Here is a TV show in England where a guy built one and provided lots of instructions.
These all run with gasoline-powered leafblowers. Some of them are designed so that the leafblower doesn't need to be destroyed. I have a leafblower, so here we go. The clearest instructions I could find for doing this were here. I found some 1/4-inch plywood in the garage and cut out an oval-shaped board on the table saw. I cut out some thick plastic blue tarp for the skirt. All this stuff came from Home Depot. Here's the leafblower, with its elliptical snout. I will need an elliptical hole in the board to put the snout in, so the underside of the board can fill with air. Here are the tools for making the elliptical snout hole. It came out a little rough, but I hope to put something soft or foamy around it anyway, to help seal it, so I think I can tolerate this much slop. There is also a hole in the center, for a bolt that will hold the middle of the curtain to the top of the board. So I got the thing put together. I connected the center of the skirt to the bottom of the board with a plywood disc strain relief. I stapled the skirt to the top of the board and duct-taped liberally all the way around the edge of the skirt. I put some duct tape around the elliptical snout hole to help the seal. I don't think the duct tape around the snout hole did much good, the gap was still quite big. I may decide to sacrifice the leafblower after all, or maybe its normal snout is removable and replaceable with a hose whose other end could be liberally duct-taped to the board. I got the thing working, after a fashion. I climbed aboard, trying standing, sitting, and kneeling positions. I had made the skirt too baggy, so the craft was much too tippy. Trying to just keep it balanced had me sweating like a horse. A couple of times, I was able to balance it well enough that it started to move frictionlessly for a second or two. Then I uploaded my FIRST GOOGLE VIDEO EVER!!! OMG PONIES!!!! I need a tighter skirt, and a better seal for the leafblower. I might want to see about finding a lighter passenger. References