A GLASS CUTTER AND A PAIR OF COMPASSESTo cut a round hole of large diameter, to make a glass disk or a ring will help this simple tool.
It consists of three parts. The dimensions of the steel rod Ø 5 mm depend on the size of the cut holes. For small radii, it is possible to use a nail without a hat. His butt drilled hole Ø 2.4 mm and tapped M3 to a depth of 10 mm. the Second part is a steel bushing with Ø 10 mm and height 5 mm machined on the machine (allowed to use the M6 nut with inner diameter about 5 mm). In the middle of the side faces of the radial drill hole and cut a thread M2,5. Finally, the third, most miniature detail — the Central focus — the make of cut screw M2,5. Sharpen the end and speel needle files flat two flats.
For mounting on the fixture a regular glass cutter with carbide rollers need to be replaced M3 screw longer so that after the Assembly he spoke at 5-7 mm.
Tool for cutting glass in round holes.
Tool for cutting glass in round holes:
1 — cutter, 2 — screw M3, 3 — shank Ø 5 mm, 4 — Central stop (screw M2,5), 5 — Bush (nut M6), 6 — cardboard, 7 — glass.
Screwing in the stud screw glass cutter, put on his sleeve and clamp at the required distance of the screw M2,5, turning it with pliers for the flats. Then glue the blank square piece of cardboard, place it on the tip of the screw, and a glass cutter and a pair of compasses ready to work.

Recommend to read

    IN THE ROOM: Public design Bureau: A. Pokrovsky. Mini-bike student (2). Small-scale mechanization: M. Povalyaev. ... Cellar wall (4); E. Evsikov. Not a lever, and a switch (7). ...
    Not just once or twice I had to dig up waterlogged clay soil at the site. The earth clung to the shovel in such numbers that further work without purification was simply impossible....