Homebrew PCBs

----- Original Message ----- 
From: "Alan King" <alan@...>
>  I load a #78 or #80 drill bit put my 1/64th" ruler behind it, and get
> it so the tip is just in front of the ruler, and visually touching the
> edge of a line, at the upper edge of the ruler.  I then advance the bit
> until the shank end of the fluted area is at the edge of the ruler, and

They use dial test indicators on "real" machinery. The ruler and eyeball are 
reasonable enough substitutes. After squaring the axis to the table, you can 
swing a bent wire in the spindle to square it to the table. The height of 
the free end above the table should be the same through a full circle.