The last time I did a successful PCB, the drill hole size relative to the component pad size is rather huge to the point where when I entered the soldering stage, the component wires were not connecting to the pads correctly.

What I want to do in eagle is change the drill holes on every device (with small pins) on my PCB so that they are about 1/64ths of an inch instead of Eagle's preferred size, that way, when I drill, I drill a small amount of copper but at the same time, the copper will meet with the hole and the odds of a strong connection are higher.

Is there a quick way I can make the drill holes smaller in eagle without having to manually edit each part one-by-one?

  • \$\begingroup\$ The general idea is that a cad package represent the manufactured result. If you want to change the resulting hole sizes, you can do that with the wrench tool, scripts, or even sed on the raw xml files. But if you don't want to change the intended size of the hole, but merely generate your etch images with smaller holes, that's the role for something like drill-aid.ulp. Contrast if you actually shrink the alleged-result defined sizes of the holes to facilitate your drilling, and then order boards from a real board house with changing them back, you might find header pins, etc won't fit. \$\endgroup\$ Jul 24, 2016 at 7:29

1 Answer 1


There is an User Language Program (ULP) for this, in the standard distribution. It is called drill-aid.ulp.

You run it on your finished PCB, before printing. it will make all the drilled pads smaller, making it easier to drill manually. As a side effect, you will get the requested function.

It will generate the extra copper in a separate layer, so that it can be removed and re-generated if you modify the board.

  • \$\begingroup\$ I don't like that. I followed it, and while it did make drill holes, I have to manually move them each time I have to move parts. I'm trying to customize my board to success. How do I quickly undo this and is there any other way? \$\endgroup\$
    – user116345
    Jul 24, 2016 at 3:29
  • \$\begingroup\$ Never mind, I figured it out. I'm sure theres a way to modify the drill on the pad itself without adding layers \$\endgroup\$
    – user116345
    Jul 24, 2016 at 3:32
  • 1
    \$\begingroup\$ @Mike Why do you think there's another way? That's the official tool to do exactly what you want, so it would probably not be necessary if there's another way. You're not supposed to perform that stage until you're finished with the layout and is going to print the final pattern, so there's no need to manually move things on that layer. Easier to just turn off the visibility, then run the ULP again. \$\endgroup\$
    – pipe
    Jul 24, 2016 at 3:37

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