The technology of drilling square holes was patented back in 1916, however, to this day, amateur carpenters use hacksaws, chisels or even ordinary round drills for these purposes. Meanwhile, to create a square hole in a monolithic wall, for example, a cabinet or a birdhouse, it is enough to attach a small fixture to a household drill.
- - Reuleaux triangle;
- - drill;
- - fixing frame.
Square holes all over the world are created using a special part named after the geometric figure of the German scientist Franz Reuleaux - the triangle of the same name. Reuleaux is a triangle, the sides of which are, as it were, curved outward. The parts based on this figure are used in a wide variety of industries, from spacecraft to household appliances. For drilling hard surfaces, a Reuleaux triangle with sharpened edges and a special hole in the middle is used. To get started, insert a household drill into such a hole. The mount must be rigid, so the drill diameter must be carefully selected. If the Reuleaux triangle has a through hole, it is necessary to bring the drilling part of the drill out from the other side of the part.
Insert the Reuleaux triangle into the retaining frame and then secure it to the drill. Thus, a device is obtained that is tightly attached to the wall, on which a hole will appear, and not "floating" in the hands of the master during active work.
If it is necessary to drill a sufficiently deep square hole, connect the drill chuck and the relay triangle with a cardan shaft. For the most efficient and fastest operation, check the frame runners for fresh grease.
The resulting hole will not be perfectly square - its corners will be slightly rounded. If it is necessary to achieve the shape of a perfect square, process the corners of the hole with a suitable size file - a small file with a fine notch, which is made of high-carbon tool steel and is used for cleaning and surface treatment of small precision parts.