A tool that allows an employee to smoothly bend a metal sheet at the right angle without much experience is called a “sheet bending machine”. With your own hands, this device can be made by having even sections of channels and corners with straight edges and planes, and a welding machine.
Surprisingly, in the practice of Russian masters the sheet bending machine is almost not widespread, and after all it gives an advantage over the mallet, which usually bends metal sheets, since it does not deform the bent part at all.
In skillful hands, this device makes it possible to ideally manufacture such complex structures as chassis, housings, casings, neatly connect the sheets into a fold, and, accordingly, improve the presentation of the products.
Before you create a listogib with your own hands, you need to figure out what parts it consists of. This is the base, clamp and crimp punch with a lever handle. The base itself is made of channel No. 14, the clamp is made of channel No. 10, and the crimp punch is made from corner No. 8. This is enough to design a tool suitable for the roofer.
The distance between the axes of the two clamping bolts should be equal to the length of the metal sheet for the roof. Profiles of the chosen sizes will allow to work with sheets up to 2 meters long. The base is mounted on gantry-type welded legs with struts. A pair of holes are drilled in the middle of the clamping profile, the distance between each of them and the corresponding end of the channel is 5 centimeters.
Special attention is paid to the lever handle, which is equipped with a homemade bending machine. With your own hands it is easiest to make it from a reinforcement bar of at least 2.5 centimeters in diameter, welding it to a corner. In order for the punch to be stable in its upper position, the handle is provided with a bend. If such a need arises, round arms made of metal can be welded to the lever as additional loads.
At the ends of the blanks of the clamp, base, punch and along the edge, a chamfer is removed with a depth of 1 and a length of 5 centimeters. After that, axes from steel rods of a two-centimeter diameter are welded to the punch. The axis during welding should coincide in direction with the edge of the corner. They are installed on the cheeks from scraps of steel sheet with a thickness of 1-1.5 centimeters.
Next, you need to assemble a listogib with your own hands. A sheet of soft metal is placed on the base for this, and a clamp fixed temporarily with clamps is attracted from above. The crimping punch is located on top, its vertical shelf should be in contact with the clamp with its entire surface. Cheeks are put on the axis and welded to the base using electric welding.
A test bending is carried out, during which the position of the upper clip relative to the base is checked and refined. If everything is correct, the design is welded.
Then, holes with a diameter of 1.4 centimeters are drilled at the base, and an M16 thread is cut into them. Threaded bolts are screwed there and fixed by welding. Valve springs which are available in the automobile engine act as squeezing.
Using a do-it-yourself bending machine is not at all difficult: the lever handle is moved to its highest position, then the clamping nuts are unscrewed. The clamp rises above the base by the force of squeezing springs, a gap is formed under it. It is necessary to skip the bent part of the sheet into it and set it at a predetermined distance from the fold line so that this line coincides with the edge of the base. The clamping nuts are tightened, and the lever handle is moved to its lowest position. As a result of these actions, the sheet is bent.
The efforts that you spend not just making a manual bending machine with your own hands will quickly come true. After all, now you can perfectly perform roofing work without attracting hired strength. And when the need for the machine disappears, it can be sold or leased. By the way, it can also produce bent profiles, which are necessary for the construction of greenhouses, hotbeds, high beds and other structures of this type.