Episode 1: The Piston-Fit Drawer
Updated: Mar 11, 2021
Invention is the mother of necessity!
That term, “piston-fit drawer”, is how some woodworking aficionados describe a perfectly-fitted wooden drawer in a cabinet: smooth, silky action with almost no side or up-and-down clearance. A perfectly-fitted drawer, though, even well waxed, can be slow to close. This is because if the air behind the drawer can’t escape as you close it, it builds up pressure. One dresser I built had this problem, because each drawer was in its own closed cavity. I tried fixing the problem by cutting holes between the cavities toward the back of the case, so that air could escape from any shutting drawer to the backs of the other drawers. What happened, though, was this: when I shut a drawer, the other ones popped open! It made me laugh.
That’s when I knew I had something. I could use the air pressure created by closing a drawer to do something else. But what? The sky was the limit!
Years later the artist and mechanical engineer in me kicked in, and I settled on this first design. It is a wall shelf with a drawer under it. When the drawer is closed, the air is forced through 2 or 3 small holes bored through the shelf into a recess in the top of it. This air stream is directed against the vanes of a wind turbine mounted on the and makes it spin. The faster you close the drawer, the faster the propellor spins! How fun is that!
The woodworker in me kicked in, and I have built and sold a half dozen or so of these. They all work great, and probably will until one is put in a really humid location. Then there could be problems…..
WARNING! NERDY DISCUSSION OF WOOD MOVEMENT AHEAD….
From a functional standpoint, drawers that are this snug are actually a bad idea! if a drawer is subjected to changing humidity it may shrink or swell, and can easily bind in its case. Wood doesn’t change length with changing humidity, but it does change in width and thickness. In my furniture I always allow some up and down slop in the drawers to allow for possible expansion in their width, but with the Piston-Fit Drawer, I had to ignore the science, flaunt my nose at the powers that be, and hope for the best.