Posted by David Sherman [24.32.202.83] on Friday, February 12, 2010 at 14:39:48 :
I'm sure there's a simple way to do this, but I can't think of what it might be. I want to drill holes precisely opposite each other in a large pipe, for a pivot. If the pipe was small, I'd just chuck it in the drill press and go through both sides at once. This pipe is over 20' long, and neither end is smooth or square, so I can't measure accurately from the ends. It seems to me that I need to do two things -- I need to make sure that the distance between the two holes, as measured around the circumference of the pipe, is the same no matter which side I measure on, and I need to make sure that a line through the centers of the holes is exactly perpendicular to the axis of the pipe. It seems like there should be a way to do it using a square or v blocks or something, but I can't think of anything. I'm surely not the first person who's wanted to do this and there has to be a simple method. Anybody know what it might be?
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