Bob's right about that being interesting, but it might not be clear to the wood butchers here that it's actually possible to turn out more accurate work than the machine on which you're doing it.
It's necessary to tweak a few things, like spindle runout and angular alignment between bed and spindle centerline. The first is done by measuring bearings from a large stock of them made to lower specs until you find some that are round within your desired tolerances. The latter is an adjustment any knowledgable machinists is capable of.
BTW... that selection of parts thing is how some manufacturers 'manufacture' super-precision parts of the same design as their 'regular' parts. Then they just supply different drawings. A Poisson distribution of parts says that if they're centered about the spec, some known amount will be of a better spec, in a narrower slice of that curve. After knowing and doing all that, with careful work and a knowlege of how the work, tools, and machine itself flex and change with temperature, you can make a part MORE accurate than the machine.
So... you 'bootstrap' yourself up. Make more accurate machines progressively until you're at the limit of the materials (thermal, mechanical flex, etc).
Because there was a time when all woodworking tools were hand-forged, the woodworking guys forget that without metal machinists, their endeavor wouldn't be as accurate or easy as it is now.
Having spent around 20 years working woods with traditional tools, I very much appreciate modern power woodworking equipment.
Lloyd