>So then you don't worry about the feed rate on the second pass? > >David Love I don't worry about it much on either pass. I don't punch it through, but I don't spin the bit in the hole unnecessarily either. I feed at the rate it seems to be cutting comfortably, and maintain roughly the same feed rate throughout. Both the first and second pass go (individually) quicker than I could do a finished hole in one pass. Two passes takes probably less than half again as long as one pass would and the results, for me at least, are far more uniform. The first pass is by far the slower, and more the struggle for me. Even with a high helix bit, a lot of big chips are coming out (or not quite coming out), and the feed rate tends to be erratic because I can't bear down on my lightweight little drilling setup without lifting the drill press off of the platform (rocking, actually) - then the bit occasionally jams with chips and has to be cleared by backing it at least partially out of the hole. All of this tends to make the first hole pretty untrustworthy, especially if it is supposed to be finished size. The second pass is effortless, produces a small quantity of very small chips (big dust), and generates no control problems since I'm only enlarging the first hole by a little over 0.015". A heavier setup might make accurate drilling in one pass feasible, but I'm impressed enough with the results from this approach to not be awfully excited about pursuing anything "better". Different strokes, and this works for me. However it's done, it's the final fit that counts. Ron N
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