With sharp sheet metal and non-metallic materials are regularly confronted each homebrew. The use of manual scissors ineffective (especially for large sheets): for large labor, cut quality is poor.
One time I used a lever shear for metal prefabrication, However, unfortunately, they were not very reliable design, and when you try to cut through 5 mm steel sheet cast iron body of the shears is burst. To acquire a similar failed: in shops and on the bases were not, and with the manufacturer replied that they discontinued. But I’m “hooked” on these scissors and return to the old-fashioned way didn’t want
It prompted me to design and manufacture devices similar to the factory, but only because of a simple tech parts that require minimal use of machine cutting equipment.
I think that readers of the journal of mechanical cutter may be of interest to many people.
Cutting of metal is carried out in two 100 mm knives, one of which is fixed on the fixed base and the other on the movable wings. The flow of scenes is made by the crank with eccentricity of 16 mm (max. stroke 32 mm), the shank of which is fixed handle. With its length of 500 mm there is an increase in the efforts more than 30 times, allowing easy enough to cut steel sheet up to a thickness of 3 mm.
Scissors for cutting sheet materials:
1 – cheek (sheet s15); 2—arm (strip 10×30, L500); 3 scenes (sheet 15); 4 — fastening of covers (bolt М8х55, 8 items); 5 — bracket (sheet s15), 6 — cover (sheet s15); 7 — Cam (round 62), 8 — arm bushing (round 60); 9,14 — movable and stationary blades (tool steel U8 U10…; band 8×20,5; L100); 10 — gasket; 11 — mount bracket to the base (bolt М16х50,2); 12 — mounting tabs (bolt М8х30, 2); 13 — foot (area 35x35x5, 4x); 15 — base (sheet s15); 16 — locking screw (М16х25); 17 — spacer (strip 15×20, L100); 18—fastening blades (screw М8х14, 4 pieces); material parts (except blades) of 40.45 steel, 40CR etc.; the arrows indicate the direction of movement of the yoke and arm when cutting
The adjustment of the gap between the knives is performed by selection of gaskets installed in grooves of the base and the yoke. Also, with pads, adjustable and smooth movement scenes.
Depending on the amount of work the scissors can be portable or fixed. In the first case, they are attached to the workbench with bar clamps set hand saws on wood. To this end, the base drilled two holes with a diameter of 10.2 mm. the Legs play the role of additional supports. At stationary position the scissors are attached with M10 bolts through the holes in the horizontal legs of the shelves.
All the parts except knives, it is desirable to carry out high-quality steel grades 40, 45, 40U, etc. Knives made of tool steel U8 U10…or P9, P18.
The proposed device successfully operated for more than two years and no raises no objections. Naturally, now no one tries to cut on it a steel sheet thickness of 5 mm. But with a sheet of 3.5 mm scissors do fine.
I. DEMIN, Krasnoyarsk