There are special devices for sharpening dull or broken drill bits If they are not at hand then try under a rotating drill bit set suitable abrasive (e.g. abrasive wheel) at an angle of 30 or 45 degrees — and the drill will self-sharpening.
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GLIDER OKTYABRENOK
Model glider Oktyabrenok (Fig. 1) simple in design. It can build every student. Needed for the production of pine slats, some plywood and tissue paper. And best of all such models to...
TO CONTROL THE MOVEMENT OF THE HAND
Before proceeding to describe the proposed design should make an important note. Developed contactless control can be applied not only in computer technology. Described constructive...
