When arranging a site or preparing for the dacha season, the need arises for arches made of profile pipes. They are needed when constructing a greenhouse, assembling a gazebo or canopy. It is expensive to buy already bent arches - the price is twice as high as for the same flat rolled products. The solution is to do it yourself, and to make the process easier (it’s very difficult to do by hand) you need to make a pipe bender for the profile pipe. You will need channels or corners, rolling rollers and some other details. Tools include a grinder with a metal disc, a welding machine, and a ruler.
Profile bender design
The machine for bending profile pipes is structurally different from the usual one. This is due, firstly, to the greater resistance of the profile to bending loads, and secondly, to the fact that the bending radius usually required is large. Therefore, the design contains three rollers. Two of them are installed permanently, one remains movable. Using a movable roller, the radius of curvature changes. In general, there are two types of pipe benders for profile pipes: with a middle movable roller and with an outer one (right or left, as desired).
You can make a pipe bender for a profile pipe in different sizes with your own hands
Pipe bender with middle movable roller
The two outermost rollers are fixedly mounted on the body. They are raised above the plane of the base. For the middle roller, a special U-shaped frame is welded. A long, large-diameter clamping screw is installed in the middle of its jumper. A third bead is attached to the lower end of this screw (can be welded). By rotating this screw, the roller lowers and rises, changing the bending radius of the profile pipe.
Design of a pipe bender for a profile pipe with a movable middle roller
A cloud is welded to one of the stationary rollers, with the help of which the pipe is rolled through the machine. To make it possible to apply less effort for rolling, two stationary rollers are connected using a chain. To effectively transmit torque, sprockets are welded to the rollers (possibly from a bicycle), and a chain is selected for them. This simple mechanism makes bending a profile pipe much easier.
With extreme movable roller
In this design, the right or left roller is made movable. It moves along with part of the base. This part is connected to the rest of the frame using powerful metal hinges.
Drawing of a bending machine for profile pipes with a lifting platform
You can change the height using a jack, as shown in the drawing. The height of the platform in this case is selected depending on the height of the jack. The bending radius is changed by lifting the movable part of the table.
Pipe bender for profile pipe with lifting platform
Unlike the previous design, this pipe bender for a profile pipe is driven from the central roller - a handle is welded to it. To reduce the required force, you can also weld the sprocket to two fixed rollers and transmit torque using a chain.
Design of a homemade rolling machine
To roll a profile pipe, you need to make a simple device that will implement the following ideas:
- the pipe moves between guide bearings installed with a small gap (0.2...0.4 mm);
- Profiling rollers will press on it from above and below. When pushing the workpiece between them, the upper and lower edges will collapse. The side edges will not change.
Rolling machine for profiling pipes 20·20 mm: 1 – stand; 2 – body-cover; 3 – rolling roller; 4 – bearing
Between the upper and lower housing-covers 2, bearings 4 are located on special axes. The distance is chosen so that with a small gap the profile pipe can pass between them.
Rolling is carried out by two rollers 3 mounted on special stands 1. They are welded to the housings so that the rollers crush the pipe by 2.0...2.5 mm on each side.
The body-cover is made of a 6 mm thick plate
The roller must be made of high-strength structural steel. 65G spring steel can be used
There is no need to use expensive material to make the stand. Regular quality steel will do
The design provides for the use of a handle to rotate the roller. Similar handles are used on washing machines produced in the eighties and nineties of the last century. They can be found at metal depots and scrap metal collection sites.
What materials and design details are needed?
The base of the pipe bender is made from a channel or two welded angles. The thickness of the shelves is at least 3 mm; select the width of the shelves and the back of the channel to match the existing parts. One rule - the base must be massive and reliable.
Several holes can be made along the edges of the platform. Through them you can fix the machine to some heavy base using large diameter self-tapping screws. Fixation is necessary, since when bending pipes with a thick wall, significant forces have to be applied and it is more convenient to work if the machine is firmly fixed.
This is what the frame looks like with welded racks for attaching the movable roller
A few words about rollers. They must be made of good, high-quality, preferably hardened steel. It is on the rollers and on the axles that hold them that most of the load falls.
It should also be said about the shape of the rollers. They should not be smooth - there should be rollers along the edges that will prevent the pipe from “walking” during rolling. Only under such conditions will the arc from the profile pipe be smooth and not twisted. Ideally, each pipe size needs its own rollers. But then the design becomes more complicated - they need to be made removable, and a reliable method of fastening must be thought out. The second option is to make videos of complex shapes, such as in the photo. Carve several steps for different pipe sizes.
Rollers for bending profile pipes of different widths
In the same photo you can see that the upper part of the bed is not smooth, but toothed. With the help of such teeth, the rollers can be rearranged to different distances and thus also adjust the bending radius.
In general, homemade bending machines for profile pipes are assembled from what is at hand or what they can find/buy inexpensively. Those who have the opportunity grind out the rollers and insert bearings. Those who don’t have such an opportunity use what they have, right down to the bushings from bicycle wheels. In general, you need to understand the design and
Tricks to make pipe bending easier
To make the rollers move better, bearings are used. But, in principle, for a homemade pipe bender, which will be used only occasionally, you can simply make holders from a corner or channel. Make a hole in them that is slightly larger in size than the axis on which the roller will be mounted. Pass the axle with the roller on through the holes of the holders and somehow fix them (at least weld on a couple of points that will be stoppers). During operation, for better performance, lubricate the rubbing areas with a thick lubricant such as Litol. This is not suitable for industrial and semi-industrial production, but it’s just right for making arcs for a greenhouse or gazebo with your own hands.
Example of turned beads
There is one more trick that helps reduce the required force when bending a profile pipe. You can use the principle of increasing gears as in a bicycle. By the way, you can use bicycle sprockets. In this case, the handle that drives the rollers is welded to a small star. It is installed somewhere on the body. Larger sprockets are welded onto the shaft axis (but teeth with the same pitch). All this is connected by a suitable chain.
With such a torque transmission device, an electric drive is not needed - it will be easy to work
And one more improvement - if you constantly use a pipe bender for a profile pipe, it makes sense to mechanize it. In this case, they install a motor that operates at low speeds.
Making a pipe bender with your own hands
The simplest pipe bender is relatively easy to make. Need to purchase:
- bearings No. 206;
- bearing housings;
- shafts Ø 35 mm made of hardened steel HRC 40...45 (suitable for the internal size of the bearings);
- bicycle sprockets of the same diameter;
- bicycle pedal;
- lead screw with nut;
- channel No. 8;
- channel No. 6;
- M8 bolts with nuts;
- strip 40 mm, thickness 4 mm.
To make it you need to use:
- Electric drill.
- File.
- Angle grinder with cutting and cleaning discs.
- Welding machine.
- Set of wrenches.
The procedure for bending a profile pipe on homemade machines
It is unlikely that you will be able to obtain the required bending radius in one go - too much force is required for this. It is impossible to create it manually. Receive the required bend in several passes:
- First, the rollers are aligned so as to obtain a slight bend, the pipe is rolled in one direction, then removed from the rolls, unfolded and inserted on the other side. It is necessary to unfold in order to obtain an evenly curved pipe.
- With the same position of the rollers, it is pulled several times until the curvature is no longer added.
- If the required bending radius is not achieved, change the position of the roller and repeat the steps again.
Rolling pipe bender with electric drive
The change in bending radius is achieved gradually, otherwise you won’t be able to make an arc from a profile pipe on a homemade pipe bender. What to do if you need to repeat the same bend? Make a graduation - note to what height the roller moved, how many times it was rolled in each position. When repeated, the differences, if any, will be insignificant.
The difficulty of bending lies in the fact that there is no scale and it is difficult to obtain the intended bending radius without experience. Sooner or later you will get it, but you can spoil a lot of material in the process.
Types of roll forming machines
3D drawing of a wearable pipe bender
The manufacturing size largely depends on the thickness and material of the pipes being bent. Do-it-yourself pipe benders can bend products made of aluminum, steel, and copper. The dimensions of the profile section depend on the location of the shafts and the possibility of their adjustment.
According to the type of installation, the bending device can be:
- permanent installation. Basically, massive mechanisms for large bending volumes are made like this. For installation, you need to make a concrete base or a welded workbench box;
- Portable profile pipe benders are of average weight and productivity. A welded base or frame assembled with bolts with your own hands is installed under them;
- wearable. Such pipe benders are created mainly for bending thin profiles and for decorative purposes. Bending installation is carried out on any flat, stable surface: concrete, steel, wood. Bending is done manually.
According to the type of drive device, machines are:
- manual - bending is carried out by transmitting muscle force. The disadvantage is the inconvenience of creating multiple bends and the uncontrolled radius of curvature;
- electric – bending is carried out by the operation of an electric motor;
- hydraulic - force is transmitted to the element by means of a hydraulic jack. This is the most common option for self-production.
You can connect an electronic bending accuracy controller to electric homemade pipe benders.
Profile bending can be roller or plate. In the first case, the pipe acquires its radius by rolling between two rows of rollers. In the second case, it bends on pins embedded in concrete. The second type is the easiest to make, but requires effort when working with your own hands.
How to bend a profile pipe without a machine
There are two ways to make an arc from a profile pipe without a profile bender - using welding and a template. Let's start with welding.
Get an arc by welding
The profile pipe is cut with a grinder on one side. They are made every 15-30 cm, depending on the required radius, cross-section and wall thickness. The cuts should not touch one side - the one that will be on the outside.
Result of bending by welding
The spare part prepared in this way is bent, giving the desired bend. For reliability, the edges of the arc can be fixed by welding a rod to them. Then welding is carried out along all the cuts, welding them. And the last stage is grinding the weld spots and treating them with anti-corrosion compounds.
Using a template
Thin-walled profiled pipes can be bent by hand using templates. If you need a special shape, it can be cut out of a piece of thick plywood or chipboard and secured to the table using clamps. On the workbench where we will bend the pipes, make about 8-10 holes. The template is placed near these holes.
The process of obtaining an arc from a profile pipe using a template
The holes are repeated at one end of the pipe; with their help, the pipe is attached to the workbench. Now the free end of the pipe begins to be pulled smoothly, forming a bend that follows the shape. You need to pull smoothly, without jerking.
The template can also be made on the ground. Pipes-pegs are driven into the ground (at least half a meter deep). They form the required arc. For emphasis, two additional stakes are driven in, which are located to the side of the arc. The distance you need to step aside is slightly greater than the width of the pipe.
Pattern on the ground
Having inserted the pipe, it is pulled towards the arc. Great efforts are required, the work is hard. This can only be achieved with a thin-walled, seamless pipe. The suture has too much resistance in the seam area. It is very difficult to overcome it manually.
