Preparing NC Drill ouput from Protel for Olimex

[Andrew]

I am designing a PCB using Protel, which I intend getting prototyped using
Olimex.

The Protel PCB libraries all refer to finished hole sizes (for example
0.8mm). Olimex require drilling information to be the unplated hole size
and indicate that the finished hole size will be approximately 0.1mm
smaller. Does Protel include finished hole sizes in its ouput files or does
it take into account plating and select a drill size slightly larger than
the finished size?

If the former then presumably I have to edit all the component footprints to
increase the indicated hole size to the actual drill size rather than the
finished hole size (e.g. 0.9mm rather than 0.8mm). Is there an easy way to
do that?

 

[James Meyer]

On Sat, 9 Apr 2005 10:41:57 +0100, "Andrew" <ajhuk@hotmail.com> wroth:

I am designing a PCB using Protel, which I intend getting prototyped using
Olimex.

The Protel PCB libraries all refer to finished hole sizes (for example
0.8mm). Olimex require drilling information to be the unplated hole size
and indicate that the finished hole size will be approximately 0.1mm
smaller. Does Protel include finished hole sizes in its ouput files or does
it take into account plating and select a drill size slightly larger than
the finished size?

If the former then presumably I have to edit all the component footprints to
increase the indicated hole size to the actual drill size rather than the
finished hole size (e.g. 0.9mm rather than 0.8mm). Is there an easy way to
do that?

The drill file is an ascii text file with a list of all the drill sizes
presented at the top of the file. It would be easy to use any text editor to
adjust the drill diameters. If there are a large number of slightly different
drill sizes, you can even combine several different sizes together into one size
to reduce the total number of different drill sizes needed.

Jim