Box 11 is a pretty fail.

I had some black walnut that I wanted to make a square box with that I had wanted to get the kinks out of my finger making before I cut into it.  After pondering for a while I came upon a method that I thought would let me make as many and as variably sized fingers as I liked with a high chance of near perfect accuracy.  The method was to have four pieces of identical wall stock, draw arbitrary parallel lines along their length, perhaps 10 or 12, clamp the pieces together and run them standing tall over the table say, incrementally advancing the stock crossward to remove every other finger space and do the opposite on the other side.  Foolproof, ya?

The fun part about devising foolproof methods is that you learn so much.  Unlike lines in geometry pencil lines have thickness.  Table saw blades too – right now I have a nicer one but I’m using the one that came with the saw and the kerf is almost 1/8th of an inch.  I kind of saw the problem right away but I figured that, having set the height of the blade to 1/2 inch, the thickness of the stock, at least there’d be no errors in that dimension and that hopefully by hand I’d be close to the mark.  I decided that the edge of the blade should meet the middle of pencil mark – the exact middle, mind you.

So you might imagine some small percentage of error crept in, what are a few sigmas here and there, and none of the boards went together right off the saw. Some of the fingers I’d made were too thin for a file to have room to adjust them.  I settled on a dremel tool with a cutter bit.  Felt like a dentist.  I got better at it but really all I ended up doing is highlighting the flaws in the method.

I had a different very nice piece of black walnut lying around.  A really nice one actually, like Biggs picture jasper almost, if you know your stones, so I figured I’d donate that for the time being to redeem this fail – can always re-purpose it.  Nonetheless it was fun – I’m curious if anyone has a hands only (no jig, no dado blade) method for finger/box joints that’s not just big Zen.

The diagonal strip across the base is eucalyptus.