At any given moment, there always seems to be at least one lively discussion going on somewhere about how accurate machines and craftsmen need to be. It would seem that there are two schools of thought on this subject.
The "old school" which, yes, I am a member, generally holds that you don't need anything more than a good square and a steel ruler to set up the typical woodworking machine, such as a table saw, jointer, band saw, etc. Obviously the requirements for high-end industrial equipment might easily require more sophisticated measuring tools. But for the most part, I have always been able to achieve a totally acceptable lever of accuracy by setting my machines up with the square and ruler.
However, there seems to be a "new school" out there, one that is composed primarily of younger craftsmen who are convinced that there is no way to accurately set up machines without the use of dial indicators, feeler gauges and digital readouts. These folks speak in terms of thousandths of an inch where we "old guys" always figured that if you were under a 64th of an inch that was close enough for top notch woodwork. We would never have worried about a variation of .003 of an inch. Maybe it's just me but I always figured that, what wood being what it is, my boards was going to "move" more than that between morning and night anyway.
It might seem like I am inviting another "lively discussion" here and you might be right to think so. I would really like to see some comments from other woodworkers young, old or whatever, that speak to how much accuracy we really need to produce top quality woodwork.