On Aug 19, 4:17*am, Tom Gardner mars@tacks wrote:
I have to make four identical 1/4" plates that have 15 holes. *11 of the
holes be countersunk for 1/4" socket-head countersunk screws that will
be used to mount fixture parts, 4 of the holes are for #10 SHCS for
mounting to the machine. *These fixtures will hold wood blocks in a
machine. *I need .005" difference between hole placement in the plates..
* The plates are 8" x 6"

My question is: *Can I stack all four plates, tack weld them together
and drill all four plates at once in the mill using the DRO to position
the plates and have the top plate and the bottom plate be within .005"?
* In other words, will the drill wander more than .005"? *I will use a
combined drill countersink to spot the holes then drill undersized, then
drill the 1/4" hole using all new drills.

Since you have to counterbore 11 of the 15 holes, it would seem that
you might save more time using counterbores with built-in pilots (type
of drill bits) and do each plate individually. With the counterbores
done on the mill, the pilot holds could be finished off on a drill
press (if necessary)
http://www.mcmaster.com/#=dos3is