Pavel's Pipe Dream
When I was invited to my first International Puzzle Party in 1999, in London, I learned that I would not be allowed to participate in that year's Puzzle Exchange event. There's a very good rule that you need to have attended IPP once before you do the Exchange, to give you a chance to soak up a bit of the party's culture and quality expectations. I decided, though, that I would produce some kind of puzzle anyway, so that I could try to trade it informally for Exchange puzzles (and others).
The only problem was that I had never designed a puzzle before! I mentioned this issue to my friend Barry Hayes and his response was both surprising and surprisingly helpful: "There are puzzles all around us! Almost everything you see is a puzzle; the only tricky part is to recognize how."
As it happened, I was in the local home center the next weekend, buying parts for our garden sprinkler system. Surrounded by all these very uniform pipes and fittings, Barry's words came back to me and I decided that there must be lots of puzzles hidden in these bins. The first thing that came to mind, of course, was a puzzle involving water moving through the pipes, but it didn't take me long to reject that idea in favor of something, anything, less complicated, less "analog". But what else would neatly fill a pipe? Well, anything round would, like ball bearings and dowels...
The result, Pavel's Pipe Dream, is shown at right. There are five dowels, one starting inside each pipe, with notches on the dowels intersecting (and therefore interacting) inside each T fitting. The ball bearing starts just inside the (sealed) endcap in the lower left corner. To solve the puzzle, you must manipulate the dowels through the little windows in the pipes to eventually free the ball. I brought more than 50 copies of the puzzle to London, and succeeded in trading all of them (and the promise of another dozen or so more) to various of the attendees. I came back home after the party drunk with the fact that I'd added something like 65 new puzzles to my collection!
I don't have any more assembled copies of this puzzle left, but I've got lots of copies of the various bits and pieces lying around in the shop. It's not my favorite of my designs, but perhaps if there's sufficient demand I'll produce one more run of them for sale. Leave a comment if you might be interested.