The need for large apertures of various diameters occurs very often. Some cut them with a jigsaw, others use a drill and then sanded the edges with a file, others are turning to so-called centraliza — fit to a normal drilling machine.
Seventh-grader Sergey Gorbunov from Tomsk designed a special machine. In just a few seconds it can be used to make a hole with a diameter of from 40 to 200 mm in almost any sheet material.
The machine is simple — it is a base with attached to it a motor power of 0.2 kW and speed 1500 rpm, counter, l-shaped with the spindle head and the clamps. Almost all machine parts except bearings, self-made; all the turned parts — material St3.
Machine for cutting through holes in the sheet materials:
1 — the base plate, 2 square mounts, motor, 3 — motor, 4 — pulley, 5 — V belt, 6 — arm manual drive, 7 — screw 8 — lever 9 — the driven pulley, 10 radial — thrust bearing, 11 — spring, 12 — movable bushing, 13 — rod, 14 — stationary bushing, 15 — feed lever, 16 — head, 17 — screw М8Х28 mm, 18 — adjusting screw 19, cutter, 20 — locking bolt М6Х20 mm, 21 — axle 22 — ring 23 — bolt М10Х35 mm, 24 — frame, 25. — bolt М8Х28 mm, 26 — washer 27 — strap, 28 — bolt, 29 — clamping sleeve.
The machine can even cut the glass discs and the holes in flat glass. For the cutter holder is fixed in the roller cutter, a spindle rotation of the machine when it is not the motor, and arm. With a little practice you can even cut holes in the case the sheet of glass. It turns out when you clean the incision with subsequent tapping the handle of the glass cutter along the inscribed circle. After that, the glass disc can be easily removed without chipping.