During construction work, such as pouring a foundation, making a floor, or installing an armored belt, reinforcement is often used. When carrying them out, the question may arise: how to bend the reinforcement so that it does not lose its strength? Many novice builders try to heat the bend angle or cut the rod at the bend site, but both approaches negatively affect the strength characteristics of the metal. The main assistant in solving this problem is often a do-it-yourself reinforcement bending machine.
What is a reinforcement bender?
This is a homemade technical tool that helps to bend reinforcement of any diameter without losing the strength of the rods.
Photo and description
As you can see from the photographs, the design of reinforcement benders consists of two main elements - a stop and a movable roller part (rod). Machines can be manual or mechanical.
If in the first case the work is carried out exclusively with the help of a person, then in the second the bending of the reinforcement is carried out due to an electric drive. Factory settings are usually made for a specific type of rod, which is indicated on the marking of the machine. However, you can make an effective mobile reinforcement bender from simple improvised means yourself.
Application area
Bending machines can significantly speed up various construction processes. They are widely used in the following areas:
- Pouring a reinforced concrete foundation. In this case, the reinforcement bender is used to bend rods when creating a frame;
- Creation of a strip foundation. Bending machines are used for precise bending of reinforcement at a given angle;
- Bending hinges, clamps or metal rings. The device is used in cases where metal cannot be bent manually due to its thickness.
Do-it-yourself bending machine (rebar bender)
If your work requires a homemade desktop machine for bending reinforcement, we suggest adopting the idea of the author of the YouTube channel Fawa Bros.
This device can be used to bend corrugated and smooth reinforcement, as well as square bars.
Step one is making the base of the structure.
We will use a channel as a base. We cut the workpiece 35 cm long.
We install housing bearings on top of the channel, and use a marker to mark the locations for drilling holes.
After this, we drill holes and secure the bearings with bolts and nuts.
Step two is making a homemade bending mechanism.
On a lathe you need to turn a shaft with metal blanks at the ends. If you don't have a lathe, you can do it differently.
We cut two blanks of the same length from the steel round timber.
We drill blind holes at the ends of the workpieces. We insert pieces of a round rod of suitable diameter into the holes and scald them. Then in the blanks themselves you need to cut grooves for the reinforcement and square rod.
We insert two parts of the shaft into the holes in the housing bearings installed on the frame, and then weld them together.
We weld a long handle-lever made of a round rod to the central part of the shaft. A travel stop needs to be welded to it.
Step three - make an axle with support rollers
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On the opposite side of the housing bearings, we weld an axle made of a round rod to the frame. We put on it two support rollers made of thick-walled round pipe.
To prevent the rollers from jumping off the axis during the bending of the reinforcing bar, washers must be welded along the edges of the rod.
The author solved this problem differently. First, he welded pieces of a metal strip with holes to the base (for fastening to the work table), then, along the edges of the axis, he welded pieces of a square rod that rest against the mounts.
Step four - installing a homemade handle stop.
You need to drill a hole in the base and weld a nut on the bottom. Then we screw a bolt into the nut, which will act as a stop to adjust the bend angle. We clean and paint the homemade product.
The completed structure can be mounted both on the table and on the floor in the workshop if you first drill holes in it and install mounting pins.
Instructions on how to assemble a compact machine for bending reinforcement with your own hands can be seen in the video below.
DIY tool | Make A Powerful Metal Bender for Construction Steels
The design turned out to be quite convenient for everyday use, and most importantly, reliable. The only difficulty may arise in the manufacture of the shaft.
Operating principle of a reinforcement bender
All reinforcement benders, regardless of the material from which they are made, work on the same principle: the reinforcement rod is placed in the gap between the movable roller and the stop. The rotating part of the machine bends the rod in the required direction and at the required angle.
Important! The moving roller must ensure bending at a maximum angle of 90 degrees, otherwise the metal rod will lose strength.
Powerful do-it-yourself reinforcement bender
This homemade product allows you to work with both corrugated and smooth fittings, as well as with corrugated pipes. Therefore, you can call it a pipe bender or a universal bender for the home workshop.
The author of the YouTube channel Kwando Technic shared how to make this device.
Necessary materials:
- channel;
- round pipe;
- Metal sheet;
- corner;
- steel round timber.
First we make the frame. For this we will use a channel. We decide on the length of the bed and cut the workpiece to the required length (80-90 cm will be enough).
We make homemade housing bearings and weld them to the frame. We install the steel shaft.
Additionally, the craftsman cuts off a piece of square rod and welds it in front of the housing bearings. It turned out to be a kind of small emphasis - just in case.
We cut out two narrow strips from sheet metal. We bend them like clamps and weld them to the frame and housing bearings.
At the next stage, we need to weld a shelf from a corner on the side of the bed, and attach a support roller next to it. We weld a fork to the end of the shaft for bending the workpieces.
Two handles must be welded on the opposite side of the shaft.
At the end, all that remains is to make a limiting stop to limit the stroke of the handle. To do this, cut off a piece of the corner, then weld it to the frame. First, drill a hole in the corner and weld the nut. We screw the bolt into the nut.
To attach the homemade product to a table or floor in the workshop, “feet” with holes need to be welded to the bottom of the frame. The final touch is sanding and painting.
You can watch how to make a device that bends reinforcement and corrugated pipe in the video on our website.
DIY tool | Homemade Powerful Metal Bender for Construction Steels
Photos of homemade machines
Here are some examples of rebar benders made at home.
Bending steel reinforcement - process features
At any construction site today you can see various equipment, many tools and devices, and almost every one of them has a machine for bending reinforcement. This is no coincidence: the most effective technology for strengthening fragile concrete structures, protecting them from destructive loads in compression, tension and bending, is reinforcement, which is performed using metal rods - reinforcement. Without a high-quality reinforcement frame, it is almost impossible to build reliable concrete walls and foundations.
It would seem much easier to reinforce corner concrete structures and adjacent wall areas using straight reinforcing bars. However, in this case, the concrete structure will be greatly weakened and may delaminate. In addition, this is a gross violation of building codes. In any corner concrete structures, it is necessary to use only bending, with an overlap of at least 80 cm on each side. A machine or a simple device for bending metal rods is also useful if you need to quickly produce connecting elements of various types - hooks, claws, etc.
When bending steel bars used for reinforcement, it is very important to know how to bend foundation reinforcement so that it does not lose its strength characteristics. To comply with this requirement, it is necessary to perform such an operation only mechanically, using special machines for cutting and bending reinforcement. In this case, it is important to ensure that the bend angle is not sharp, and that the radius of curvature at the bend is from 10 to 15 diameters of the rod itself. It should be remembered that a steel reinforcing bar bends without losing its strength characteristics up to an angle of 90 degrees, then the strength indicators begin to decrease.
When bending steel reinforcing bars with your own hands, two mistakes are often made:
- a notch is made at the bend site using a grinder or other tool;
- The section of the reinforcement where the bend will be located is heated using a gas burner or blowtorch.
After such procedures are completed, some primitive means for bending is used: a heavy hammer, a sledgehammer, a piece of pipe, a vice, etc. These bending methods lead to a significant weakening of the reinforcement, which can cause the destruction of concrete structures. In such cases, you should always remember that you need to bend the reinforcing bars without violating their integrity and only if they are in a cold state.
In general, everything here is expensive and serious - full automation and many settings. For home craftsmen, this video is provided for informational purposes only. Since spending 130-180 thousand rubles on such a unit for non-professional use does not make any sense.
Industrial wire bending machines
In serial and large-scale production, machines that work with wire in coils are used. Such units provide cost-effectiveness and good productivity when producing metal products of the same type. Devices are installed on the machine, configured to obtain a specific configuration.
Work process:
- installing a coil of wire on the unwinder;
- a long product is affected by two mechanisms - roller and flat;
- the aligned wire enters the machine into bending devices;
- the part of the required configuration is cut off by a mechanical cutting device.
This type of wire bending equipment produces parts of simple shapes. The number of bending operations usually does not exceed 5.
Bending wire at home
To give simple shapes to not very stiff wire, use metalworking tools, available in almost every home workshop:
- Pliers . With their help, you can bend or securely fix the end of the product.
- Pliers . A type of pliers.
- Wire cutters . With their help, metal products are cut into measured pieces.
To create complex shapes, templates are used, which are checked against during the bending process. To bend a rectangular clamp, the end of the wire is clamped in a vice, and bending is carried out with pliers or hammer blows.
Safety rules for manual bending:
- work must be carried out wearing thick fabric gloves;
- it is necessary to ensure tight fixation of the material being processed;
- There should be no heavy objects on the table on which work is carried out that could fall to the floor.
The principle of bending reinforcement
The principle of operation of the bending machine is based on the fact that the reinforcement is firmly fixed (one or two ends) and, when pressed by the operator, reinforced by a lever or a system of levers, it is bent at the desired angle.
According to building codes, the bend angle of the rod must be such that the concrete in the finished reinforced concrete product is not damaged or crumbled at the bend site. The bending of the rod along a notch or under the influence of elevated temperature is not allowed - this will reduce the strength characteristics of the rod, and, as a result, the future structure. Reinforcement can only be bent “cold”. The simplest bending machine consists of two angles connected by a bolt. In the simplest, but not the most reliable, version, they don’t even need to be welded together.
Performing a bend
When bending, you must comply with construction regulations for a specific type of reinforcement: for example, the permissible bend angle A-III is 90 degrees, provided that the bend radius is not less than 6-8 rod diameters. If the reinforcing bar is bent by 180%, the strength will decrease by 10%.
Types of professional equipment
The simplest type of professional equipment used to bend wires are machines with one console. Meanwhile, such devices can only produce products of simple geometric shapes, the development length of which does not exceed 1000 mm.
More complex products with a development length of over 1000 mm make it possible to create double-cantilever equipment, in which the workpiece is deformed simultaneously from both ends. This machine can produce products with many complex curves.
The most complex wire products allow the creation of 3D machines on which bending can be performed simultaneously in three dimensions. The machines of this category are endowed with such unique functions by a rotary bending console, all movements of which are controlled by an electronic automated system. Despite all the advantages of processing using such equipment, it is quite expensive, so these machines are used in exceptional cases.
Working with a wire bending machine
To produce a large number of bent products from wire, various techniques can be used, each of which uses special equipment. The most common and economical method is the coil bending method.
Bending using this technology occurs in several stages.
- The wire, which is wound on coils, is fed to a two-plane roller machine, which aligns it.
- After alignment, the wire is fed to a wire bending machine, on which the product of the required configuration is formed.
- The formed product is cut off, and the entire bending cycle is repeated again.
The use of this technology allows you to fully automate the bending process and thereby achieve high productivity.
Budget wire bending machine
A wire bending machine can also look like a stationary template around which the wire is rolled using movable pressure rollers. Using such devices, bends of even the smallest radius can be formed on the surface of the wire, the value of which is comparable to the outer diameter of the workpiece. At the same time, the configuration of the product formed on such a machine can be quite complex.
The adjustable stops and variable arms of this template allow you to create many combinations of wire bends
A wire bending machine can also operate on the principle of pushing the workpiece through a system of rollers. When using such equipment, the end of the wire is connected to a special wire, which pulls the product through the working parts of the machine. A wire bending machine of this type, due to the features of its design, allows the production of products with even very complex shapes.
When leveling the wire, a wire bending machine is also used, which in this case is used for straightening. The working parts of such equipment can be straight frames or two-plane straight blocks. At the same time, rotating straightening frames are more efficient, which is why they are used in cases where leveling the surface of the wire needs to be done as smoothly and efficiently as possible.
