Usually methods of work can be attributed to the demands of the process, the tools at hand, or the pleasure of the user.
My favorite moments in the shop are when I know that there is an elegant method for the task at hand and I get to think it over. I usually look around the shop at my masking tape, string, straight edges, mirrors and rubberbands. There are few issues that I've run into that these vital tools can't tackle.
Recently, Greg Pennington introduced me to lasers, and while they might not find their way into my work in the same way, they have opened some doors that I've been knockin' on for some time now.
So often in "classic" chairmaking, the curved arm rails or crests are connected to the seat by straight spindles. This is no problem, as all sorts of straight surrogates can be used to site for drilling. But when using curves spindles, there is an offset, in that the holes in the seat don't point directly at the holes in the crest.
Here is how I've solved the problem. In the past, I would have set this up and used a protractor to read the angle that splits the two spindles to get the rake. Then I would have set up a mirror to drill at that same angle. The trouble with this method is that usually, by this time in my process, I have already carved the seat, and the mirrors become unwieldy.
Here come the lasers, with their lovely ability to create lines in space. As you can see, I use the same simple set up and split the difference with the laser for the rake, and for the splay, I line up with the mortise in the seat straight to the hole in the rail for the splay.
Then I simply remove the spindles and drill, using the lasers to guide the bit.
I have done this many times with my previous means, but I've never seen such dead on and even results. After the first couple of mortises were drilled, I noted a spot on the back of the drill to register and recreate the offset, then I drilled the rest by eye.
The ability of the laser to "wrap" around surfaces has been making all sorts of complex marking and locating easier for me. It only makes sense that visually defining planes in space would be a helpful in chairmaking, where so much of what we do is connect lines in space!