Start the hole squared on and then after you get down to where you have a
few thou of wall, work the drill over to the 45 deg. angle while it is
turning.
The alternate is to make up a block that will guid the drill at the 45 deg.
angle and clamp that where you want to drill the hole. There are drill
guide inserts that will keep the block from being chawed up available.

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Why isn't there an Ozone Hole at the NORTH Pole?