July292022

Metal cutting machine with your own hands: manufacturing technology

From this article you can learn how to make a metal cutting machine with your own hands at home using the simplest materials. All the stages of creating structures based on a cutting disc or grinder are described in detail here: preparation of materials and tools, calculation formulas, detailed step-by-step instructions, as well as related information with useful tips.

A metal cutting machine made with your own hands will allow you to get equipment that is ideally suited to the needs of the owner

Metal cutting machine with your own hands: recommendations for creating

Disc cutting machines are tools based on the design of which there is a special platform or frame made of metal. The machine itself is equipped with parts that ensure reliable fixation of the material in a certain position at the required angle during its cutting.

As a cutting element in such constructions, a disk made of high-speed steel is used. It is also called carbide. It can also be used for cutting a metal circle with a coating in the form of an abrasive material. The cutting element is driven by an electric motor with a belt or gear drive.

Diagram of the device of a pendulum-type metal cutting machine

Pay attention! In low-power versions of the tool, it is allowed to use a cutting element mounted directly on the shaft of an electric motor. In other cases, such use of the disk can be dangerous.

Disk machines have three different feeds of the cutting component:

lower;
pendulum;
frontal.

According to the number of cutting elements , machines are:

single–head – only one cutting disc is included in the complete set of the device, therefore, if it is necessary to replace the operation, the cutting edge is readjusted in accordance with the new task;
two–headed – the design makes it possible to work with two tools at once, thereby increasing efficiency. In such machines, one head is in a fixed position and maintains stability, the second head can move. Two-head structures can work automatically.

An example of a metal cutting machine made with your own hands

Making a disc cutting machine for metal with your own hands: the procedure

In the manufacture of a machine designed to work with metal, the actions are performed in the following order:

Protective covers are being prepared, which will be installed on the drive belt, as well as the cutting disc.

The motor is installed. The drive belt acts as a connecting part between the shaft of the cutting element and the motor.

A shaft is manufactured on which the drive pulley will be fixed, as well as a cutting disc is installed. The assembly is subject to assembly and subsequent installation on the pendulum. In this case, the movable upper part of the structure acts as a pendulum, where the cutting element and the motor are located.

A shaft is made for mounting the pendulum.

The frame for installation of the machine is executed. The spark trap and the workpiece will be fixed on it.

The pendulum is mounted on the frame.

Electrical wiring is being installed.

A trial start-up of the tool and equipment adjustment is carried out.

As a cutting element in homemade cutting machines, a disc made of high-speed steel or a circle coated in the form of an abrasive material is used

Calculation of a pulley for a homemade metal cutting machine

The calculation of the diameter of the pulleys is carried out taking into account the rotational speed of the disk and other parameters. Assuming that the engine power will be at least 300 watts, the rotational speed of the disk will be at least 3000 rpm, and its size in diameter is 40 cm.

Useful advice! In the process of metal cutting, the nut in the fixing zone of the disc can turn away. To avoid this, it is recommended to place the drive pulleys on the left side, and the disk itself on the shaft on the right.

Usually the discs are marked by the manufacturer, who applies the maximum permissible rotational speed value to the product. In this case, the indicator is 4400 rpm. Therefore, it is allowed to choose any speed within 3000-4400 rpm. /min.

Data for calculations:

the rotational speed of the motor is 1500 rpm.;
the diameter of the pulley intended for installation on the shaft is 6.5 cm;
the rotational speed of the disk is 3000 rpm.

Drawing of a frame-type cutting machine (frame dimensions depend on the size of the tool used)

The calculation is performed in the following sequence:

We set the length of the shaft along the perimeter. To do this, the number π, which is equal to 3.14, is multiplied by the diameter size: 3.14 x 6.5 = 20.41 cm (the length of the shaft along the perimeter).

The resulting value is multiplied by the required number of revolutions: 20.41 x 3000 rpm = 61230 cm/min.

The result must be divided by the number of engine revolutions: 61230 cm/min / 1500 rpm = 40.82 cm (the length of the pulley for the engine along the perimeter).

The resulting value is divided by the number π: 40.82 cm / 3.14 = 13 cm (the required size of the pulley).

Calculation of the belt length for a homemade metal cutting machine with your own hands

To perform these calculations, the following data will be required:

parameters of the drive pulley (radius);
distance separating the center points of the pulleys;
parameters of the driven pulley (radius).

Having 2 pulleys with dimensional parameters of 13 cm and 6.5 cm, it is possible to make the necessary calculations. Since the distance between the centers of these elements can be changed (since it is required to bring the belt into a state of tension), a 50 cm long segment will be taken as an example.

The larger the diameter of the cutting element, the easier it will be to cope with cutting thick metal

Now we need to calculate 1/2 of the circumference of each of the pulleys. Since the drive belt passes between them twice, double the distance between the center points must be added to this value.

First pulley (circumference):

3.14 (number π) x 3.25 cm = 10.20 cm

Second pulley (circumference):

3.14 (number π) x 6.5 cm = 20.41 cm

Drive belt (required length):

20.41 cm + 10.20 cm + 50cm x 2 = 13.06 cm

Useful advice! To get a more accurate result, it is necessary to make calculations with the maximum and minimum distance between the central points of the pulleys and select the average value.

In order to independently manufacture the design of the machine for working with metal, you should prepare the necessary tools.

Drawing of a pendulum—type cutting machine: on the left — the dimensions of the base, on the right – the design features of the pendulum

A mandatory set of tools and materials includes:

welding machine;
metal corner (steel);
channel and chain;
the button to turn on/off;
bearings;
shaft and electric motor;
electric drill;
sheet steel for creating a work surface;
a box for placing the electrical components of the machine.

Principles of creating a metal cutting machine

The scheme of making a homemade machine is subject to certain principles, they need to be taken into account before you get down to business:

it is very important to choose the right transmission and install it. The safety of the torque and its correct transmission from the motor to the cutting element (disc) depends on this component;
be sure to provide for the presence of a vise. This tool contributes to a more comfortable work, as well as increases the degree of its safety;

The presence of a vise increases the level of comfort and safety when working with a homemade machine

choosing the optimal cutting angle. The permissible range is within 45-90°. In most cases, experts prefer cutting at right angles;
the diameter of the cutting disc is selected taking into account what materials the master will work with on this machine in the future. The larger the diameter of the cutting element, the easier it will be to cope with cutting thick metal;
when designing and drawing up drawings, such indicators as the dimensions of the future machine and its weight are necessarily taken into account. These values are directly influenced by the materials from which the equipment will be made. The layout of the parts also matters.

Pay attention! When drawing up drawings, special attention should be paid to vibration supports that are installed on the legs.

Assembling a metal frame for a cutting machine

After all the tools are prepared and the drawings are selected, you can proceed directly to the process of creating the machine. Using a steel corner, it is necessary to make a frame part of the structure. In accordance with the drawings, which can be compiled independently or found online, the elements of the frame are cut out. All of them are connected to each other by welding. First you need to check the size correspondence.

The process of creating a frame for a metal cutting machine

A channel is welded to the upper part of the frame – it will become a guide element and will serve as the basis for further installation of the cutting component on the machine. This channel will become a kind of link between the electric motor and the cutting element. After that, vertically positioned racks are fixed on it with bolts.

It will be necessary to weld the construction of another frame. The dimensional parameters are selected individually, taking into account the dimensions of the electric motor and its features. When choosing an electric motor for a machine, it is better to pay attention to asynchronous type modifications. This type of equipment is characterized by increased reliability and durability.

There is one subtlety when choosing a motor. The more powerful the engine, the smoother the drive will be.

Assembly of the electrical component for the machine

The installation of the equipment involves the installation and connection of the working shaft to the electric motor of the machine. The way in which this can be done is not fundamental. If the drawings have instructions for performing this procedure, it is better to follow it, since the correct operation and reliability of the tool depends on the quality of installation.

For homemade cutting machines, it is better to use asynchronous type electric motors

Useful advice! Some parts that cannot be made independently can be ordered from a turner. These include flanges for fixing, as well as a pulley.

To fix the motor on a metal frame, it is better to use a bolted connection with nuts. It is recommended to place a box near the engine, where there is a switch and an electrical circuit, as well as a remote control for controlling the tool.

The channel, designed to fix the cutting disc, is better placed on a spring. You need to make sure that when you release it, it returns to its original place. To fix the spring, you can take bolts and a clamp.

The electrical component is the most important part of the instrument. It is mandatory to include a start-up circuit in the design, as well as a button for emergency shutdown of the machine. It is necessary to achieve such an arrangement of parts in which the electric motor will be connected to electricity by means of an automatic machine and a box, and not directly. A three-way automatic starter will be enough to turn on and fully start the engine. It will also power the off button.

Finally, it is worth taking care of the availability of protective devices that will protect a person in the process of work. To do this, you need to make a protective casing. It will prevent sparks and small metal particles from getting into the eyes.

The protective casing is a prerequisite for working with a self-made metal cutting machine, protecting the eyes from sparks and small metal particles

Making a cutting machine from a grinder with your own hands: drawings, technology

The designs of cutting machines made on the basis of a grinder are of two types (depending on the placement of the grinder).

In the first case, a bed is obtained on which an angle grinder is very rigidly fixed. Only the disk rises above the work surface, for which there is a special slot in the table. Such a machine operates on the principle of a circular saw.

Pay attention! In the process of working with such a machine, it is necessary to move the workpiece independently, which is why the accuracy of work is lost. In addition, this process may be unsafe, so drawings with a hidden type of placement of the grinder are not in high demand.

The second option assumes that the workpiece remains stationary, and the cutting element moves. Due to the fact that the grinder is located on top of the countertop, no serious effort is required to cut the parts.

Work on a homemade cutting machine created on the basis of a grinder

The list of tools and materials for the cutting machine from the grinder with your own hands

When making a tool independently, it should be borne in mind that the accuracy with which it will work largely depends on the stability of the structure. For this reason, the thickness of the materials for manufacturing is not so much related to the requirements for the strength of the machine body, but rather to the need to ensure the proper level of rigidity.

List of materials:

profiled pipe with square cross section (2.5×2.5×0.25 cm);
sheet steel (sheet thickness 0.4-0.5 cm);
profiled pipe with rectangular cross section (4x2x0.25 cm);
ball bearings – 2 pcs. (No. 203, 204 or 202);
calibrated rod no more than 10 cm (thickness is selected taking into account the hole on the inner bearing cage);
metal rod (diameter 0.8-1 cm);
fasteners (bolts with nuts, thread M or M8);
metal tire (2×0.4 cm).

The accuracy of the cutting machine from the grinder largely depends on the stability of the structure

List of tools:

angle grinder;
electric drill (can be replaced with a drilling machine);
drill set;
a set of dies designed to form a metal thread;
welding machine;
horn keys.

Choosing the right cutting tool for a homemade cutting machine from a grinder

The angle grinder is the main nodal part of the machine for working with metal. Experts do not recommend using a small tool for these purposes, which has a power of no more than 500-600 watts. In such grinders, the cutting discs have a diameter of no more than 12.5 cm. These limitations are due to the fact that a cutting element with a large diameter is considered universal and very reliable – it is able to cope with cutting thick blanks.

Useful advice! Instead of welding to fix the parts, threaded connections can be used, but they are less reliable and will not be able to provide the necessary level of strength.

A competent choice of a grinder is an important point when creating a metal cutting machine from this tool

It is also necessary to carefully approach the choice of a grinder because there is a wide variety of designs on the market. Since this power tool is not fully unified, the construction of the machine will be carried out under a certain modification and dimensions of the angle grinder.

If the machine breaks down, installing another grinder may not only be problematic, but also impossible. We’ll have to redo the pendulum and all the fasteners. Therefore, it is worth choosing a tool from the assortment of large and already proven companies, for example, Bosch or Makita.

Drawings of a cutting machine: how to make a cutting tool from a grinder

At the preparatory stage, the design and drawing up of drawings is carried out. There are no uniform sizes for the reason that the design of each machine obeys a specific model of the cutting tool. Ready-made drawings, of which there are many on the web, can be adjusted to the grinder. They allow you to orient yourself in relation to what the structure of the structure will be, its dimensions.

Drawing of the bed for the grinder

Drawing up a drawing is better to start with the body part. In some cases, it may be necessary to build a separate platform instead of a frame. Such a platform will be fixed on a locksmith’s workbench. Next, the dimensions and the nature of the location of the nodal elements on the machine are determined. It is necessary to measure the axial distances between the mounting holes located on the gearbox, as well as measure the grinder itself.

All this data is used for drawing up drawings. After the fastenings for the pendulum and the grinding machine are designed, a rotary assembly is developed.

Useful advice! The accuracy and rigidity of the machine depends on the distance between the cutting element and the hinge joint. The smaller the gap, the better. It is recommended to install a pendulum with a minimum length.

After drawing up the drawings, it will only be necessary to select materials, calculate their quantity and proceed with the construction.

After drawing up the drawing, selecting the necessary materials and tools, you can proceed directly to the creation of a cutting machine

Technology for creating a cutting machine from a grinder

The manufacturing technology of a metal cutting machine based on a grinder is almost the same as in the case of a cutting disc:

Preparation and manufacture of parts for the frame.

Arrangement of the swivel joint on the pendulum arm.

Manufacture of a U-shaped bracket with holes for mounting the gearbox of the grinding machine.

Manufacture of a U-shaped clamp and a strap that will fix the body of the grinder on the pendulum.

Mounting of the U-shaped clamp and U-shaped bracket to the cutting tool: by welding or threaded connection, all these parts are attached to the cantilever part.

Pressing bearings into supports.

Double-sided pressing of bearing assemblies onto the shaft. To increase the strength of the joint, you can tin the axis with a thin layer of tin using a soldering iron.

Fixing the pendulum with supporting nodal parts on the edge of the platform (0.5-0.6 cm margin from the edge) using a welding machine.

Installation of a grinder and a protective casing.

Installation of the return spring.

After the structure is assembled, it is necessary to perform a test run and check the correct operation of the equipment, as well as the placement of all parts on it. At the final stage, the groove is adjusted for the cutting element, supports are installed designed to secure the workpieces.

When the finishing is completed, the machine body must be covered with a thin layer of enamel. Staining will protect the tool from damage that rust can cause.

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