- Sheet and edge benders: how they work
- Appointment at construction sites
- Real-world example
- More expensive is better?
- Improvements and homemade products
Real editing is not illustrations in technical albums: you almost always have to improvise in non-standard conditions of the object. Manufacturing of complex-shaped frame parts, brackets, metal coatings from sheet metal – all this becomes possible with the use of manual bending machines.
Sheet and edge benders: how they work
There is more than one way to bend metal in the field without sacrificing much precision and quality. In the simplest bending benders, the force is transmitted by a massive bending beam, tightly fixed in the pivoting hinges from below. Due to the high hardness of materials and a tight fit, movement is carried out practically without backlash and within a strictly defined area. A rod system or just a long lever makes it possible to bend metal up to 3 mm thick only due to the muscular strength of one person.
There is also a wide range of mechanized devices for electrical and hydraulic operation. Bending of sheet metal in them is carried out by stamping, rolling on rolls, or using a roller carriage. Some technical solutions are also used in hand-held machines: roller knives, edge bending machines and folding machines. Longitudinal rolling machines can be manually driven: they are arranged in the manner of roller pipe benders, but with a much wider working part.
And in each of the categories, in turn, there are indeed many varieties. Distinguish listogibs mainly by the thickness of the processed material. It is determined by the force of the working body (N mm2) and the characteristics of the metal itself, thus, the same machine can bend aluminum, carbon and stainless sheets of different permissible thicknesses.
The specifics of the processing of parts also determine the width of the working part, the width of the bent section (grip), the bending angle, the presence of special devices, the clearance of the pressure beam, dimensions, weight and overall reliability.
Appointment at construction sites
The fields of construction and manufacturing that use metal stamped parts are truly numerous. To imagine how strongly the average crew depends on the supply of roll-formed steel, consider the construction of a typical cottage from the roof to the foundation.
Steel roofing, for all its weaknesses, is quite affordable and has an impressive resistance to wear and tear. Sheet bending machines serve as the basis for the production of standing seam roofs, profiled sheets and metal tiles. Many types of coatings require metal protection of valleys and skates, here sheet bending equipment is used just as often.
Moving on below: systems of horizontal and vertical gutters, point snow holders – all this is also made by flexible and stamping. All kinds of brackets for façade glazing subsystems and hinged façade coatings with significant dead weight. Even load-bearing structures can use bent hardware to hold panel and frame elements together. And if you continue to the independent manufacture of containers and housings, or, say, special assembly and metalworking workshops, it will immediately become obvious how firmly sheet benders have entered the world of modern engineering..
We have a good example of how the bending machine became a real workhorse for the assembly team specializing in ventilated facade systems. Brackets, tables and consoles, from which the substructure is assembled, have a price of 20 to 50 rubles, and they are used in thousands.
In addition, the standard assortment does not always correspond to real requirements. There are also atypical deviations from normal geometry due to design refinements, design features and other factors. Below is a good example of how to follow the technology even in difficult working conditions without inventing new and untested mounting methods..
First, an old manual bending machine was purchased for work for 20 thousand rubles with a working part a little more than a meter long. Also, a drilling machine was hastily built from a Soviet drill – no frills, just a vertical feed and a small bed. The goal was to test the production of parts, clarify the production flow chart and the processing sequence.
It all started from the basics – small-scale production of non-standard parts, bending brackets. Over time, the need for periodic procurement of piece items has become less pronounced. According to average estimates, 120–150 parts came out of the sheet when the facade was moved 50–70 mm from the supporting structure. That is, the parts were not only always at hand and in the right quantity, they cost almost half the price.
For six months of operation, the equipment staff was updated. The homemade drilling machine was replaced with a new machine with a pair of chucks for a quick change of running diameters. For cutting, a reciprocating guillotine was purchased from a sheet bending manufacturer and a band saw machine for cutting the formed profile and making cuts for segment bending.
The stimulus for such a serious renovation was the listogib itself: after several series of work with a 1.5 mm sheet, it finally loosened up, moreover, several times it was necessary to weld cracks in tense nodes. Considering the experience of work, now there is a clear understanding of what kind of bending machine is needed. A segment machine was purchased.
More expensive is better?
In the example above, a small batch production line is equipped with the simplest and most affordable equipment. But you can often find examples of the opposite, when even for trivial work the best samples of equipment made in Japan or Western Europe are purchased. Why is this happening?
The fact is that the cost of equipment should be equivalent to the value of the parts produced on it, for a specific volume of such production. Let us explain at the extremes: if a coil of metal is put into a rolling mill with a defect in rolls, in the event of a defect it will become unusable in its entirety. While the piece and non-decorative elements can be modified or reworked even after rejection.
The other side is that you have to know exactly what you plan to make and what operations your machine should perform, what the size of the parts is at each stage. In simple words, a listogib should be “enough” for specifically set purposes: for the installation of gutters, an electric listogib is an obvious excess, while the manufacture of cases and boxes without a good segment machine is hardly possible.
Improvements and homemade products
The high price issue is also a matter of ergonomics. It is unlikely that cheaper machines will have a good fleet of additional components that facilitate cutting, rolling, and precise angle control. But buying a very expensive machine just because it comes with a cool roller knife is still not worth it.
First of all, because similar equipment can be found from a number of manufacturers from China or even domestic ones. Such equipment works not so hotly, but it is quite maintainable and replaceable.
For a real professional, the machine is just a base, which is subject to mandatory revision. The frame, beam and hinges are difficult to reproduce yourself, but to facilitate your own work is a completely natural and fulfilling desire. Basically, work on machines is carried out in three directions:
- motorization and withdrawal from muscle traction;
- strengthening of the structure due to the increased power;
- improving safety and improving working conditions.
The modifications are very diverse: from an elementary extension of the feed table and gripping depth, to a total change in the concept of work and alteration of the manual drive system. And about such trifles as a home-made roller cutter for cutting is out of the question: such topics have long been exhausted in professional forums, where more than one recipe for making such devices was offered. As well as the ways of its inclusion in the unique construct of the machine.