DIY roller knife for sheet metal - homemade instrument, the demand for which is growing every day, which is explained by the productive speed of operation of such a device and its simple design. The mechanical basis is extremely simple, and is based on two metal knives rotating in opposite directions, pressing into the steel plane of the workpiece, which leads to its cutting.
The classic design involves the installation of rotating disks at the top and bottom, classified according to the material of manufacture:
- Parallel roller knives - used for cutting steel sheets into strips, while maintaining good quality blanks.
- Roller knives with one inclined edge - this design, in addition to slicing, allows you to cut workpieces with rounded shapes.
- Roller knives with multiple inclined edges - maintaining a small radius, helps to produce parts with curved lines and rounded shapes.
Design
Roller metal shears, assembled at home with your own hands, have a common essence that remains unchanged - the presence of a cutting knife. It is made from steel alloys with a maximum strength threshold and other characteristics that should be higher compared to similar parameters for steel that will be processed on a cutting machine.
In practice, it is known that roller knives for cutting metal produced at the factory have a service life of about 30 km of steel sheets, with a caveat to the maximum sheet thickness, which will not exceed 0.5 mm.
Accordingly, if the thickness of the material is higher, then the durability of the tool is reduced. However, nothing prevents you from sharpening the tool and thereby extending its service life.
Necessary materials
A machine for cutting sheet metal, constructed with your own hands at home, requires knives, the range of materials for which is very wide, and the choice of one of them mainly depends on the type and thickness of the material that will need to be cut. If you have to work with not the most durable, thin sheet steel, such as aluminum, then ideal option the simplest bearings will become. But for the required functionality of a roller knife, they lack sharpening, which should be carried out independently along the entire end of the future tool.
The main roller knife is installed on a movable part of the structure with a pressure handle, which, when pressed, clamps the workpiece between two cutting surfaces. The diameter of the bearings directly affects the speed of work performed. That is, the larger the bearing diameter, the higher the production speed on the machine.
To simplify the work with the tool and make it more convenient, it would be nice to equip the sheet cutter with a guide plane.
Manufacturing and installation of this part does not constitute a lot of work, and in return it will greatly simplify the whole process. The output is universal machine with roller knives, which can interact with other metalworking equipment, which can also be easily constructed at home.
Manufacturing instructions
Factory models of cutters sold in stores, even in standard configuration, will cost a large amount. The price of models offered on the market starts from 20,000 rubles. Such conditions are not beneficial in purchasing tools for home use or in a small workshop, and it will be used extremely rarely.
To begin with, the main body of the instrument is designed, which everyone chooses for themselves. The main attribute of the machine is manufactured - a roller knife for sheet metal. The material from which the part is made directly affects the durability and performance of the unit. As mentioned above, the strength characteristics should be significantly higher than the similar characteristics of the material being cut. Otherwise, the minimum problem will be a low-quality cut, forcing the craftsman to clean and process the edges of each cut piece.
Do-it-yourself roller metal shears are mostly made from bearings. Sharpening the ends of the part forms the cutting surfaces. The main roller, connected to the drive, is attached directly to the handle. The lower one is installed on the fixed lower part of the machine. If you have skills in processing iron alloys, manufacturing such a device will take a maximum of a little more than a week, including setting up the unit.
Features of metal cutting at home
Circular knives are an excellent replacement for metal shears, having a number of advantages:
- Small dimensions and dimensions.
- Simplicity of design.
- Easy adjustment.
- Convenience and ability to work with a wide range of materials.
Do-it-yourself sheet metal cutting at home is usually done with cutters or drills. Of course, this approach helps to give the part the desired shape, and at the same time polish the surface. However, it would be much more practical to construct a machine with roller knives with your own hands once (unless, of course, we are talking about cutting scrap metal, since accuracy is not so important there), thereby reducing both the time allotted for processing and minimizing the amount of debris and defects that may occur when using hand tools. To put it simply, circular knives are an excellent replacement for metal shears and even an industrial guillotine.
Cutting metal at home is a rather tedious process. And its quality often leaves much to be desired, forcing additional processing of the resulting edges. The situation can be corrected in many ways by using special devices, including those made by yourself. We will talk about one of these devices, namely the roller knife, today.
Roller knives for metal
The roller knife is gaining more and more demand and popularity today. This is due not only to the high productivity of such a device, but also to its fairly simple design. The principle of operation of the mechanism is simple - two cutting disc rollers rotate in different directions, pressing into the surface of the metal and thus cutting it. Friction between the metal and the knives ensures unhindered movement of the workpiece along the tool.
In the vast majority of cases, roller knives for cutting sheet metal include two rotating rollers - an upper and a lower one. Depending on the variation of the cutting element used, such tools can be classified as follows:
- Parallel position knives - used for cutting metal into strips, while providing very acceptable quality;
- Edges with one inclined - this group allows not only longitudinal cutting of material, but also cutting out ring and round workpieces;
- Multi-oblique knives – similar devices make it possible to carry out effective cutting of workpieces of round, curved or ring formation with a small radius.
It is worth noting that all of the above variations cope perfectly with cutting sheet steel, while the cut edges do not require additional attention and subsequent processing.
Homemade roller knives
With all its undoubted advantages, even the most simple model A roller knife has a pretty decent price. This is the reason why it is inappropriate to purchase it for one-time work or periodic use. However, the optimal solution from a financial point of view still exists - a roller knife can be made with your own hands at home.
The design of such a device can be very different. The most common variations are presented below (photo, photo 2). But in any case, the main part remains unchanged - the cutting knife. It should be made from the most durable and reliable steel alloy, the strength parameters of which must necessarily exceed those of the material being cut. If this condition is not met, the quality of the cut will be low, which will require additional processing of the cut edges.
Practice shows that the working life of factory-produced knives is about 25 km of sheet steel, provided that its thickness is 0.5 mm. With greater thickness, the resource will be correspondingly lower. However, the tool can be sharpened without any problems and continue to function effectively.
If we talk about the resource homemade knives, then it is directly dependent on the material from which the cutting parts of the unit are made.
What can a knife be made from?
The options can be very different; here you need to pay attention to what exactly you plan to cut. So, if it is not the most durable sheet steel in its structure, including aluminum, galvanized metal and other similar materials, the most ordinary bearings will be a completely suitable solution. True, for this you will have to pre-sharpen their ends.
To carry out cutting, one of the rollers, the one that will play the role of a drive, is installed on the handle, due to which the knife will be pressed to the metal. Please note that the larger the diameter of the bearings, the more higher speed it will be possible to cut the material.
In order for the cutting process to take place with maximum comfort and accuracy, the device can be additionally equipped with guides - this will not be particularly difficult, but it is guaranteed to serve you well in the future.
The resulting tool is quite versatile and can be used in conjunction with a wide variety of metalworking equipment, including sheet bending machines, which you can also make yourself at home.
cutting sheet material parts are performed using various tools. Roller shears for sheet metal cutting are popular, a trend due to their simple design and high productivity. The device is used in industrial and small workshop environments.
Characteristics of scissors
The intended purpose of roller knives is to cut steel sheets up to 1 mm thick. They are necessary at the site for the production of ventilation ducts, when working with roofing metal, during the construction of a fence and arrangement of the roof.
The mechanism is used to produce semi-finished products for subsequent bending of profiles for various purposes. The equipment is installed in car body repair shops. In auxiliary production, blanks are prepared for the assembly of racks and cabinets.
Scissors with rollers will successfully replace manual option or guillotine due to a number of advantages:
- Compact dimensions and light weight.
- Simple device.
- Convenient to use.
- Just getting set up.
- Suitable for working with sheets of different materials: aluminum, tin, steel, roofing iron.
The processed product is obtained with a clean cut and no burrs or bends. It is easy to cut sheet metal with such a device.
Scissors can be purchased at a specialized store or made independently. It all depends on the volumes performed and the economic component. With a daily cutting rate of 30–50 meters or more, an industrial design will be required.
Description of scissors
The task of dividing a sheet of metal into parts is solved by destroying the strength bonds on a local segment.
The power part consists of two cutting roller discs with multidirectional rotation. Their cutting edges lie in the same plane. When rotating, the rollers are pressed into the surface and cutting occurs due to shear deformation. The sheet metal is fed to the tool by friction of the knives against the metal.
The design of the cutting mechanism includes two rotating rollers located one above the other. Depending on the design of the cutting part, roller knives are distinguished:
- With one inclined edge for straight longitudinal cutting and cutting out round and ring workpieces.
- With parallel position of knives, cutting material in strips with high quality. They occur most often.
- With several inclined edges for convenient cutting of curved, round and ring-shaped workpieces with a small radius.
All types of scissors provide cutting of sheet material with high quality, without the need for subsequent cleaning of the cut edge.
To increase productivity and obtain an even cut, the housing with roller knives is installed on a stationary machine.
The cutting equipment includes a bed with supporting surfaces, equipment for fixing the material and a roller knife. The latter contains a body made of steel gauge, an overhead handle, cutting rollers, and a mechanism for adjusting gaps in several planes.
Material for cutting discs serves as tool steel.
The manufacturer sets an average service life of 25 km to cut sheet metal with a thickness of 0.5 mm. With increasing thickness, the service life decreases proportionally. The cutting element is subject to regrinding, which significantly increases the service life.
How to make a roller knife
Purchased model roller shears Even the simplest design is unprofitable for purchase in a small workshop or private household. It is not necessary to use it often, and the device is expensive. The optimal solution is to make your own scissors.
The design of the mechanism may be different, but at the core there will always be a cutting knife in the form of a roller. The selected material for making knives determines the performance of the device and the quality of the cut. Knives must be strong and reliable, with a surface hardness significantly greater than the hardness of the material being cut. Otherwise, you won’t get a high-quality cut; the edges will have to be processed additionally.
Homemade roller knives are made from bearings. To do this, the ends are sharpened to create a cutting edge. The drive roller is mounted on the handle. When working with it, the knife is pressed into the workpiece. The lower roller is installed permanently. During the cutting process, you need to press the handle with the roller with one hand and pull the sheet of metal with the other.
Choice larger diameter bearings will increase cutting speed.
For convenience and precise cutting, additional guides are installed.
Adjustment is carried out using oval holes, a set of spacers and special bolts.
If you are proficient in metalworking techniques, manufacturing a cutting device takes 7–10 days, including setup.
At first glance, it may seem that the same methods are applicable for cutting corrugated sheets as for cutting sheet metal. This is not surprising, since it is almost impossible to visually distinguish a profiled sheet from a corrugated sheet, but the cutting methods of these two materials are significantly different.
Tools for cutting corrugated sheets
It is necessary to pay attention to the fact that corrugated sheeting can be cut in several ways.
All methods not only have their own nuances, but may not always be applicable in individual cases. Let’s take a closer look at how to cut corrugated sheets as conveniently and quickly as possible.
Cut the material only with a special disk with carbide teeth - such disks are inexpensive and are sold in almost all hardware stores. Using such a carbide disk, you can get an almost perfect cut, but for such work you need to choose thin disks, up to 6 millimeters. Of course, if it is not possible to use such a disk, you can get by with a diamond-coated disk, but in this case it will not be possible to cut a stack of several sheets at once.
If this option is not considered for some reason, you can use a jigsaw, which, unlike a grinder, leaves a more even cut and does not “burn” the material in the cut. As in the case of the grinder, you will have to change the regular file to a metal file. The best option- file 75 mm long with fine teeth oriented upwards.
The last option is to cut the profiled flooring using metal shears. This method is not suitable as the main method, but using scissors, you can quickly cut profiled flooring along the surface (for example, if you need to cut it into thin stripes). Of course, this method has two obvious disadvantages: not entirely straight edges and a significant loss of time. It is impossible not to mention the “intermediate option” - electric metal shears, but this is a real professional tool that is not available to everyone and is not sold everywhere.
If you are cutting sheets of profiled flooring for renovation at home or in the country and do not consider it necessary to purchase a jigsaw or grinder specifically for this, cut with a hacksaw.
Despite the fact that, as in the case of scissors, this is an exclusively “manual” method, cutting a profiled sheet with a hacksaw is much easier, since the sheet does not offer resistance.
In addition, it is worth considering that in this case there is no aggressive effect of high temperatures on the cut, as a result the edge is smooth and undamaged. The only thing a hacksaw is not suitable for is cutting out complex geometric elements from a sheet.
Now that the issue with the cutting tool has been clarified, it is necessary to add a few words about cut processing. Professionals know that when using “hot” methods (grinder and jigsaw), the coating of the profiled sheet is damaged and the cut itself is charred. Not only is this unsightly, but it also takes extra time to straighten and clean up the cut. Moreover, professionals never use autogen for cutting corrugated sheets.
Of course, it is preferable to cut corrugated sheets using scissors or a hacksaw. In this case, you need to decide what is more important: speed or quality. In any case, after cutting the corrugated sheeting is completed, care should be taken to ensure the durability of its service. Most main advice, which is appropriate here: be sure to process the cut, ideally this should be done with factory paint. This paint is usually sold in any hardware store, and most manufacturers of profiled sheets include paint complete with corrugated sheets.
Sheet metal cutting can be described as technological process, as a result of which metal product is divided into parts, acquiring specified shapes and sizes.
The article describes the processing of sheet metal, talks about methods of cutting metal, describes roller shears, automatic lines, etc., and also discusses special equipment for processing sheet metal (machine, cutter, etc.).
Cutting methods are divided into two main groups: mechanical and thermal.
Before choosing a specific type of cutting, you need to know the advantages of each type, the essence of the process, and in what cases a particular type of cutting is used.
The basis of mechanical cutting is cutting tool, having characteristics of strength and hardness higher than those of the metal being processed.
This processing method is also called cold. Mechanical processing includes guillotine, band saw, water jet and grinder cutting.
Cutting with scissors and grinder
To cut metal using this method, special guillotine shears are used, which can be used for thin sheet metals (profiled sheets, galvanized).
The cutting element is a knife. Guillotine shears can be mechanical, automatic, pneumatic, or hydraulic.
Manual and pneumatic guillotine shears have the lowest prices of all types of equipment designed for straight cutting of metal.
However, an inexpensive tool has low productivity, so you have to put in a lot of effort.
Therefore, most often preference is given to special power tools or industrial equipment, which work much easier and faster.
An electric tool is an angle grinder (angle grinder).
This is due to the fact that abrasive wheels reduce the protective characteristics of the metal. When cutting with a grinder with your own hands, you must follow safety precautions: your eyes and hands must be closed.
The main danger when working with an angle grinder is the flying of fragments.
Effective cutting with a grinder is carried out by the heel of the disc - the near lower part of the circle. The tool must be turned off every 5 minutes to avoid overheating.
If you are cutting long pipes with a grinder, you need to start from the hanging edge. Thick parts are cut straight with a grinder.
Guillotine shears work according to the following principle: the sheet for cutting is located on the table between the knives.
The metal must be pressed against the table with a beam, and then the upper knife must be moved.
Guillotine shears provide precise cutting of metal, which is explained by the clamping mechanism. Guillotine shears are designed for longitudinal and transverse cutting of sheet metal. This slitting device is the most popular.
Another type of tool is applicable for square, round and angular metal, due to the fact that the knife is positioned at any angle. The main characteristics of the device are the length and thickness of the cut.
Guillotine shears provide an even cut without roughness; the knife does not spoil the paint and polymer coating and the characteristics of the product being processed.
There are also disc shears for longitudinal cutting, which is carried out with rotating round knives.
The lower and upper disc knives rotate in different directions at the same speed. The movement of the workpiece is ensured by friction against the knife.
Sheet metal cutting disc shears are primarily used for roofing works for longitudinal processing.
Disc shears work like this: the sheet to be processed is placed on the machine and inserted between the support and clamping rails.
Then the sheet is fixed with clamps and the disc shears move along the cutting line. When the disc shears begin to rotate, the knife cuts the product.
Disc shears are easy to use when slitting metal yourself (especially if the cutting lines are pre-marked). The knife produces precise and high-quality cutting.
This tool is intended for longitudinal cutting only. Automatic lines are quite popular.
Automatic lines consist of a feeding device, an unwinding device, a material feeding mechanism, a cutting unit and a control panel.
Automatic slitting lines have the main advantage: there is no need to involve people, since all operations on the line are carried out under the control of one person.
Roller shears are often used. The roller knife is used for straight and shaped cutting. The roller knife is suitable for cutting round, oval, and square shapes.
Band saw cutting
For such cutting, roller shears are not suitable, but a machine with a band cutter that has teeth is used, the distance between which is selected based on the quality of the material being processed.
Cutting has excellent characteristics: high performance, good cleanliness processing, thin section not exceeding 2 mm.
This machine is capable of processing any alloys. One of the advantages is that cutting can be done at any angle.
The machine also has disadvantages: the inability to perform figure cutting.
Waterjet cutting is used for materials of varying hardness: concrete, stone, different types metal, etc. The basis of this method is the use of a mixture of abrasive materials and water.
The machine supplies the mixture with a pump high pressure, reaching the highest speed, which ensures cutting.
This method is one of the most promising, it allows thin metals cut without abrasive materials, only with water.
Thermal types
Thermal cutting of sheet metal is based on thermal action, after which the cut area melts and burns. The main methods are gas, plasma and laser cutting.
Gas cutting
Cutting and bending using oxygen and flammable gases has affordable prices. The method is not applicable to all materials. Can also be performed figure cutting.
The condition for high-quality cutting is the combustion temperature of the metal exceeding the melting point.
The principle of the technology is this: the surface is heated to 3000°, which depends on the metal being processed.
This temperature is achieved using a mixture of combustible gas and oxygen.
For a high-quality cut, the volume of gas supply and the speed of the cutter must be correctly adjusted.
This method is mainly used for installation work, in the production of metal structures.
The method is not without its drawbacks, which include the large width of the seams and subsequent processing.
Also, when the surface is heated unevenly, deformation and deterioration in the quality of the metal occur.
An advantage is the ability to process products up to 20 cm thick, with a cut of 2.5 mm.
Plasma cutting
Plasma cutting of sheet metal is modern method, in which a plasma jet is used instead of a cutter.
The basis of the method is the use of gaseous substances in a high-temperature plasma state obtained under the influence of an electric arc discharge.
Cutting can be done in two ways: jet and arc. When processing with an arc, the sheet is included in the circuit, an arc is formed between the metal and the electrode. In jet machining, a cut is formed between two electrodes.
Homemade devices can act as a plasma cutter
The plasma flow occurs on a plasma torch that has an electrode that forms an electric arc.
Plasma cutting is used for cutting and bending various metals up to 20 cm thick.
Thanks to high temperature there is no thermal effect on areas located near the cut, which prevents deformation of the sheet and does not impair the characteristics of the metal.
This is especially important when working with stainless steel. Curly cutting can also be performed.
Do-it-yourself plasma cutting and bending hand-held devices, in which the start of cutting is the moment the plasma arc appears.
During the process, a distance of up to 15 mm must be maintained between the plasmatron nozzle and the metal.
Laser cutting
A laser machine for cutting and bending metal is the latest equipment. Laser cutting of sheet metal is based on the thermal energy of a narrowly focused laser beam.
The main advantages of the technology include accuracy, cleanliness of processing, and thin cuts.
The method is used for jewelry and other products that require complex shaped cutting and bending. It is advisable to use the method for metal with a thickness of no more than 15 mm.
Equipment prices are not the lowest due to the newness of the technology.
The essence of the method is as follows: high-intensity laser ray is aimed at the metal, heating the product.
After which the surface begins to melt at the point of contact, and the adjacent areas also heat up, but do not deform or lose their characteristics. As the beam moves, it creates a thin cutting line with smooth edges.
Tool for laser cutting presented coordinate tables, mating with a head controlled by microprocessors.
Laser machines perfectly process fragile products and carbide materials.
Sheet metal processing is carried out different ways(roller knife, machines, cutters, etc.), from which you can choose suitable option cutting and bending with your own hands. And homemade devices can be used for bending.
