Robert Scott schrieb:
When parts are loaded from various Eagle libraries, the hole sizes in
through-hole parts can have all sorts of values. Some board
manufacturers charge extra if too many drill sizes are needed. It
seems it would be desirable to make some compromises on the hole sizes
to prevent, for instance, 0.039" holes and 0.040" holes in the same
design. Most likely these two sets of holes could be all one size.
Is there any built-in way in Eagle to accomplish this? I know I could
copy all the various parts from the Eagle libraries and make my own
custom versions of those parts for a given project in a special
project library. But that is a lot of work. Is there an easier way?
Simply make use of drill tolerances in the CAM processor.
First, run drillcfg.ulp to collect all drill sizes in the board. You can
edit the list (remove unnecessary values) before saving it to a file.
After that, use a drill device with separate rack file (I normally use
SM1000). Set the drill tolerances to reasonable values (like +/- 3%).
The CAM processor will simply use the "nearest fit" within the
tolerances for all drills that are not exactly in the rack.
Tilmann
P.S. Besides, it's always good to have your own libraries with correct
and contiguous drill (and other) sizes.
