Re: [CAD_CAM_EDM_DRO]floating z axis

In a message dated 23-May-02 14:12:16 Central Daylight Time, wanliker@...
writes:

> You also might consider a vacuum table to hold the board flat

Bill: I have seen plotters, and have BUILT a couple using vacuum, but that
REQUIRES that the blank be ABSOLUTELY-flat, preferably somewhat compliant, as
is paper! Further, drilling a PC-blank with FEWER than an average hole-count
opens up enough "leak" that even a 29.9" vacuum at the start would be
useless.

Besides, you need a "perforated grid table-top" for this, and the drill MUST
pierce through the working stock, so the "first one" would destroy your
table-top! Putting a "backup board" (waste) over the table, then the blank
on top of that, would defeat the vacuum aspect in the first place!

Further besides: If you want to drill a 4" x 6" board on a "vacuum area"
that is 12" x 19", what do you do, then, with the BULK of the unused
perforated table-top? That's a LOT of 2" wide masking tape, and things get
messy very rapidly with that!

Just one of those "been there, done that" things! Jan Rowland


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