Dear Neil, I enjoyed Howard Lewis' article "A Simple Drill Grinding Aid" issue 293. A great little project for a newcomer and one that will certainly provide the basics to coming to grips with drill sharpening that so many find a challenge. I have attached a photo of another simple aid I discovered many years ago. By using Howard's tool to ensure similar angles this aid ensures both cutting lips are the same. The jig can be fabricated from whatever scrap is available and requires a base approx. 70mm × 40mm with a sharp pointed spigot ideally 60 degrees or more, located approx. 15mm from one end on the centre line. On the other end of the base a perpendicular flat section is firmly attached and should be approx. 300mm high × 40mm wide. Checking for equal lip lengths is made by holding the drill upright and placing the centre hole in the back of the drill onto the spigot and leaning the drill over towards the vertical flat section rotating it so that the corner edge of the lip is able to scratch a line on the vertical flat, by rotating the drill 180 deg. the other corner can scratch a line. If the lips are equal the two scratch lines will show as one, if not then the higher mark lip will require a touch up to get it right. Black marker pen is ideal to apply to the vertical flat section in order to highlight the scratch.
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