On Sun, 23 May 2010 14:20:06 -0000, you wrote:
>I used to use a drill press, but the two sides are occasionally mis-aligned.
I use two single sided boards and epoxy them together. Use very stiff
pins for the alignment, very tight fit, so the boards cannot wobble.
Also use long setting epoxy, just because.
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>I went to free hand dremel drilling so I could hold it at a slight angle and hit the center of the pad on the opposite side. I etch the hole in the center of the pads out so the copper guides the bit into the center.
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Then you may not be using carbide drills.
>Then one day I had an idea. (hey, it could happen).
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>I now drill about 1/2 way through from one side freehand, flip the board over, and drill the rest of the way through from the other side. The tiny bit tends to hit the hole that has already been drilled and self-center. Only rarely do I have a through hole that is not exactly in the center on both sides now.
Not sure that this would work with carbide drills, since they tend not
to like any sideways stress.
Harvey
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