Re: [CAD_CAM_EDM_DRO] gauge blocks was Re: Rolled Ballscrews

>
> The price of full 81 pc. "B" grade(shop grade;+-/50 millionths)Gauge
> block sets (Jo-blocks) has come down so far as to make them a good
> choice for a serious hobbiest. Going this route will cost a bit more
> than 30 bucks(about 80), but you also will have a VERY accurate
> standard for all your precision measurements... And you didn't need to
> buy the ground stock, and spend time sanding/sizing.

But the Jo-blocks won't stack up to more than a few inches - not much good
on an 8ft table. Another solution is to square up the ends of some bar
stock without regard to their exact length. Then con somebody into
measuring them on a CMM at work. I've pulled this one off a few times.
Nobody seems to mind. The bars don't have to be any particular length as
long as you know what length they are.

A better tool would be a ladder block as shown in Moore's book. For our
purposes, a piece of square bar stock with transverse slots milled every
inch or so down its length would work. Take it to the same nice guy with
the CMM and get the left (or right) face of each slot measured and recorded.
Again, exact one inch increments aren't necessary. Just don't stamp the
numbers in the bar after it is measured.

If I recall, Nyquist says you can move the bar and take measurements between
the previous ones to improve the quality of your map.

Doug