Perfect Jigs (Which are Handcuffs)
I spent an entire week planning and building the jig shown in the photo above. Though it looks like a platform for holding Roman candles, it actually allowed me to drill four legs in a seat blank without worrying about rake and splay.
I would simply clamp a seat blank inside the jig and let the pipes guide my auger bit as it bored the perfect angles for the front legs and back legs. Then I removed the seat blank from the jig, shaped it and built the undercarriage – joining the legs and stretchers.
I built a dozen chairs using this jig. It worked brilliantly. But one day I put it on a shelf in the basement and haven’t used it for more than a decade. Why? Because the jig was perfect – and a perfect prison.
Every chair out of my shop had legs with the same rake and splay – it didn’t matter if it was an interpretation of a Welsh stick chair from the early 19th century or a modern design of my own. The jig never faltered. So I used it for everything, perhaps even when I shouldn’t have.
The other downside to the jig is that it allowed me to make chairs without truly understanding rake, splay, sightlines and resultant angles. Because I didn’t have to know those things in a deep way to make bang-on mortises, my understanding of the concepts was a bit dim. And that held back my ability to design new things.
What was the turning point? A deadline. I had to build a stool, which wouldn’t fit in my jig. And I had to do it really fast, so I didn’t have time to build a second jig. So one night (yes, that’s all it took), I sat down with the trigonometry tables in Drew Langsner’s “The Chairmaker’s Workshop” and figured out the calculations behind chair angles.
(Since then I’ve figured out a way to do this without trigonometry. I wrote the article “Compound Angle, No Math” for the June 2015 issue of Popular Woodworking Magazine to explain this process.)
The next day I made the stool and put the jig away. On the one hand I was happy (I understood the trig), but I was a bit disgusted with myself (that I had put it off for so long).
The experience made me look around at what other jigs I had in my shop that were holding me back. And I’m still looking to this day.
— Christopher Schwarz