[quote="JPG40504"]Another bad on my part. I responded after reading today's initial post without reading(remembering) all that preceded it in this thread. Doing so would have eliminated the first 'bad'.
I gotta side with Dusty in that perhaps you are expecting perfection with the joints of wood which is not an absolutely accurate medium to begin with.]
I'm not actually expecting perfection. Although I do confess to being heavily influenced by the machine-tool world, where I have spent the last 15 years of my career. "Precision" in the machine tool industry these days typically means tolerances of about 0.001" or better. With my Shopsmith equipment, I find that I can realistically shoot for about 0.005" .. i.e good enough that the error doesn't matter in wood. And the wood is
much prettier than the metal.
A concept from metalworking that I believe applies equally well to woodworking is that of "machine capability". Let's say that you need to make a part with a tolerance of 0.005". If your machine has a repeatability of 0.003", you can probably make acceptable parts. BUT, the machine must be set up nigh unto perfection, and if the material varies, the tooling wears a bit, or maybe even the temperature changes, you are out of tolerance. You CAN make good parts, but a skilled operator has to be monitoring the process constantly, and tweaking the adjustments as required. Thus, strictly speaking, the machine is not "capable" of holding that tolerance all by itself. In the industry, the technical term for this is "expensive"
. And your competitor who invested in a machine that repeats to 0.0005", but can make good parts all night long, with no one attending it, is going to eat your lunch.
For me, woodworking is a hobby, and so the economics are irrelevant. But I simply hate having to rework and correct parts. At least the third time around. (The first two times are fun and educational opportunities to diagnose the problem and develop a process fix.
). Hence, if I find something about my equipment that can contribute more than about 0.002" of error to my workpiece, I will try to correct it. Why? Because it will make it much easier, and thus more enjoyable, to machine the finished wood part to 0.005". Or to 1/64", for that matter, if that is your personal standard.
None of which should be construed as advice for any other recreational woodworker. Heck, I love to do freehand turning, where the only criteria is how well the shape pleases your eye! For me, I simply don't want mechanical fit details to detract from the pure aesthetics of woodworking. I'm slowly learning how traditional woodworking craftsmanship techniques can address these same issues. But in the short term, I inevitably build upon what I already know.
