Some CAD systems generate drill files which do not have the same scale or offset as the Gerber files. In such cases, the scale or offset must be adjusted manually so that the drill holes match their corresponding pads in the other layers. These adjustments apply to all drill files, including any drill files added to the product after scaling. If the drill files do not have the same scale, then this must be corrected by the CAD program. There are typically two kinds of scaling errors:
Decimal point errors: To adjust for decimal point errors, click one or more times on the x10 or ÷10 button. x10 makes the drill image 10 times larger than it was, while ÷10 reduces the drill image to 1/10 of its size.
Inch/mm errors: In the same manner, the x25.4 and ÷25.4 buttons may be used to adjust for inch/mm errors.
It may take some trial and error to find the correct scale. Avoid using x10 or x25.4 after having used ÷10 or ÷25.4, since this will lead to some loss of precision in the hole coordinates. It may be a good idea to use File|New product and reimport your files once you have found the correct scaling factor.
Once you have found the correct scale (and rotation and mirroring, if necessary) use the Autolink|Create filter from current mapping command to create a filter which includes these drill file parameters.
Note: If you are having difficulties getting the correct scaling of drill files, you can open the files in a plain text editor (such as WordPad) and modify them manually. Adding something like the following 3 lines, to the beginning of the file, will specify the correct scaling to the Import module.
M48
METRIC,TZ,000.000
%
In this example, metric coordinates without leading zeros and 3 digits after the decimal point are used. If coordinates are in inches, then the first parameter should be INCH. If trailing zeros are omitted, then the second parameter should be LZ. The third parameter should list the number of digits before and after the decimal point (such as 00.0000 or 00.000). If your file already contains any of these lines, then you should only add or edit the text which is not present. A drill file should only contain one of each of these three types of lines.
