If you've ever seen a piston fit drawer or interior tray in action, you know it's like watching magic. A piston fit sees one part sinking into another on a cushion of air, which requires what seems like an impossible amount of precision to get right. This isn't the kind of precision that comes from using CNC technology, but rather, human judgment, good preparation and knowing how, when and where to apply finesse.

Professional furniture builder David Barron, who has mastered the technique, gamely shares every last secret of how this is done in the videos below. I found them hugely informative.

In Part 1, Barron shows you the preparation required to make the tray, which he then assembles prior to fitting:

In Part 2, he demonstrates how you actually get the thing to fit so perfectly, using a variety of techniques to detect where the problems are and eradicating them:

I was surprised to see Barron provided the information for free; this is the kind of thing you'd typically pay hundreds of dollars for to take a class on. Thanks David!