A figure of speech, sorry, your implementation, is the same as the "cross hair" explanation, the base of the drill press will already have a hole lined up with the drill bit, the "viewer" just lines up with that hole, he added a small plastic insert to his assembly with a black ring drawn on it to reduce the appature for greater accuracy. the light would shine through the FR4 copperless areas pinpointing each pad, with my failing eyesight it might be worth a try!!
David
--- In Homebrew_PCBs@yahoogroups.com, "bebx2000" <bebx2000@...> wrote:
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> I am sorry, but I don't see any mention of cross-hairs in his implementation. My take on this is that he is blackening the circular insert, positioning the fixture and bit and drilling a hole for alignment. The PCB is then positioned to get the pad concentric with the drilled insert hole.
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