Foam cutting machines: principle of operation, types, prices. Homemade Styrofoam Cutting Tool - Buy or DIY? The choice of foam for arranging thermal insulation

Polyfoam is a popular building material used as insulation or decorative trim. Despite the seeming simplicity of processing, it is not recommended to cut it with a tool with a high speed of rotation of the cutting element; disc grinders and jigsaws are not suitable. The main reason is the coloring of the foam around the edges. For sawing a small volume of slabs at home, a thin saw or a clerical knife is used, in all other cases it is advisable to make it yourself or buy a machine with one or more filaments.

A thin hot edge or string is used to create neat edges on products. It smoothly cuts polystyrene foam in a given direction, the size of the working field and productivity depend on its length. The number and nature of the arrangement of threads in machines for cutting foam plastic can be different: the more there are, the higher their efficiency. In advanced models with the ability to work in 2D and 3D modes, up to 12 heated strings are installed. According to the manufacturer's instructions, one person is enough to ensure a continuous process on this equipment.

Varieties of machines

Depending on the type of construction and performance, all machines are divided into:

• Portable models that resemble a jigsaw. This variety is easiest to assemble with your own hands.
• Numerically controlled machines for cutting large volumes of polystyrene foam.

Depending on the processing method, equipment for longitudinal or cross cutting and models for obtaining complex shaped products are distinguished. In different tools, either the thread or the material moves.

Review of popular models

The products are presented by Russian companies, when choosing a machine for cutting foam, its performance, the ability to adjust the power and connect to computer control, the size of the working field and the number of threads are taken into account, all these data are indicated in the instructions. Popular semi- and professional equipment includes:

The cost of equipment and the main characteristics are summarized in the table:

Model name	Rated power, kW	Machine dimensions, mm	Weight, kg	Price, rubles
SFR-Standard	≤2,5	2400 × 1250 × 1200	140	140 000
FRP-05	≤3	1300 × 700 × 1300	75	290 000
SRP-3420 Sheet	1,7	2 places: Timber frame 1300 × 690 × 490 Cardboard 340 × 480 × 210	90	143 000
SRP-3220 Maxi	1,5	2200 × 1250 × 1100	97,7	176 000

Making a machine with your own hands: a guide to action

To create a device at home, you will need: a table, a nichrome thread, a 220/12 V transformer and a rheostat or LATR (adjustable laboratory autotransformer), iron springs. A sheet of plywood, chipboard, OSB boards, walls of old furniture can serve as a support. The width of the working surface is selected taking into account the size of the foam, and the length is 1.5-2 times greater.

Next, the marking is carried out: approximately in the middle of the table, but at a distance of at least 15 cm from the edge, stands for the filament are installed (it is advisable to draw up a drawing of the device in advance). In the simplest case, it can be a long screw or a stud secured with nuts, with the help of which the required cutting parameters are adjusted. A cutting thread is attached to one stand at the required height. To the second - a spring with the subsequent connection of the same filament element. It is needed to tension the string, since the metal expands during the heating process, and it sags. A conventional counterweight can be used as a tensioner.

Nichrome metal alloys are best suited for cutting foam with string or wire. They are used in most household appliances - electric ovens, hair dryers, irons, or sold separately. Nichrome thread heats up to a temperature of 1200 ° C without a noticeable loss of mechanical and physical properties, unlike ordinary steel or copper wire, investments in this element will definitely pay off.

Next, the main element of the circuit is connected - the lead wire. Reliable connection methods are selected: rigid twisting, through a terminal block or a bolt. Consider the significant value of the flowing current, the minimum allowable cross-section is from 1.5 mm 2 and above. A 220V 12V step-down transformer is used as a power source, it is necessary to ensure safe work when cutting material at home.

The connection diagram of the IP to a homemade machine is simple: the primary winding is to the outlet, the output ends of the transformer are sequentially through the rheostat to the heating thread. Ideally, only LATR is used. Calculation of the parameters of the power supply is impossible without some knowledge of electrical engineering, but in the simplest case it is taken into account that approximately 2.5 watts of power is required per 1 cm of length of a 1 mm thick nichrome thread. When you multiply the length of the filament by 2.5, you get the desired value for the power source.

At the final stage, with the help of a rheostat or LATR, the heating temperature of the thread is regulated and the optimal feed rate of the material is selected (on which, in turn, the cutting thickness depends). If it is necessary to create a machine for figured modeling of foam products on our own, the scheme becomes more complicated. In particular, additional threads are introduced into the drawing, perpendicular to the working base. Making a table for cutting with your own hands allows you to significantly save money, the estimated cost of the necessary elements is 10,000-12,000 rubles, while the price of semi-professional equipment reaches 140,000.

Polyfoam is a versatile material. It is used in construction (insulation), in the production (repair) of household electrical appliances, interior design, advertising. One of the main characteristics of the material is density. The higher this indicator, the stronger the material. However, this has a great impact on the price.

When using the material as a filler for wall insulation, the most loose structure is usually chosen (due to its low cost). However, loose foam is difficult to handle - when cutting, it crumbles heavily, making it difficult to pick up garbage.

The styrofoam knife should be thin and sharp, but this does not prevent the edge from breaking. Even if you work outdoors, the flying small balls litter the environment.

Therefore, professional builders cut polystyrene with nichrome wire or hot plate. The material is fusible despite fire safety.

Important! When choosing a heater, pay attention to the characteristics. It should say “self-extinguishing”. Such foam is perfectly cut with the help of temperature, but in case of fire it will not become a source of combustion.

The industrial foam cutting machine can process sheets of any size, cut the material both across and along the solid.

However, cutting foam at home does not imply such volumes and sizes. When repairing your home (or garage), a compact thermal knife is sufficient. It can easily cope with both linear cutting and curly adjustment of slabs when laying in areas with complex shapes.


Any tool has a cost, and there is always an opportunity to save money on a purchase.

DIY Styrofoam Cutting Tools

The guillotine is perfect for linear cutting. Only the impact will not be mechanical, otherwise a lot of debris will be formed. We use a proven technology - cutting foam with a heated tension string.

Required materials

• Nichrome (tungsten) thread
• Power supply, preferably regulated
• Any construction materials: timber, metal profile, pipe, for the manufacture of a tension frame
• Furniture guides for drawers.

On a table, workbench, or other flat surface, we install vertical racks for attaching the guillotine. Using furniture guides, we fix the cutter frame so that it moves without distortion. Both sides must move synchronously.


The most critical part of the cutter is the wire mechanism. The first question is where to get the material. Nichrome can be purchased at radio electronics stores. But since we are striving for a shareware design, we will look for an alternative.

1. Old soldering iron. Models made in the USSR, designed for 36-40 volts, can be found in any home workshop. Heater winding is an excellent donor for nichrome guillotine. True, the length of the wire is no more than a meter.
2. Iron with classic spiral heater. The wire is thicker, suitable for linear cutting. Shaped cutting is permissible, with low accuracy requirements.
3. Spiral heaters from a hair dryer, or fan heater. The principle is the same, they are not suitable for precise cutting.

note

Tip: When straightening the coil, do not pull the wire along the spring. Loops may appear and the thread will break. It is better to unwind the turns as from a spool of thread. You can put the spiral on a nail or pencil and pull the wire across the turns.

The principle of the frame is shown in the diagram

The wire cutter must be electrically isolated from the frame. Therefore, it can be made of metal. It is important to maintain a constant tension on the wire. When heated, nichrome expands, adding up to 3% in length. This causes the string to sag.

Polyfoam (extruded polystyrene foam) is used as thermal insulation for external and internal decoration, used for packaging goods or manufacturing prefabricated structures. The material is produced in the form of sheets, which are cut on site and adjusted to the dimensions of the surfaces. For fast cutting of foam, you need a special device that allows you to make a straight or curly cut.

Manual processing of foam is possible at home and in small workshops using a simple device assembled from scrap materials. Extruded polystyrene foam has a fairly dense structure, therefore slabs can be cut with a metal toolheated to a certain temperature. As a cutting surface, a wire that supplies an electric current is suitable, with the supply of which the main difficulty of assembly is associated.

A self-made machine makes it possible to obtain tiles or bars of suitable thickness from ordinary foam plastic for packaging with their further use in various structures. With such a device, you can also cut out foam rubber or similar materials that are needed for the manufacture or repair of upholstered furniture. The compact dimensions of the device for cutting foam with your own hands using nichrome allow you to install the machine in a small workshop or even on a balcony.

To cut foam at home, you need a structure that can be assembled from simple materials available at any hardware store. First, you need to determine the parameters of each element, taking into account the dimensions of the foam plates that will have to be processed ... In most cases, the following details are sufficient:

1. The base is made of dense plywood, chipboard or solid wood. You can order new parts or use elements of old furniture (doors, walls, shelves). A 400 x 600 mm base is sufficient for working with foam.
2. A string or wire in the form of a thermal knife for foam plastic.
3. Metal studs, screws, springs or regular nails for fixing the wire. The installation height of the cutter depends on the expected thickness of the finished boards.
4. Mounts for parts on the base. A few self-tapping screws are enough to fix the structural elements.

It will take up to one hour of working time to assemble a thermal cutter. Each of the structural elements can be quickly replaced during the repair process or expanding the capabilities of the device.

Algorithm of actions

To make a device for cutting foam or similar materials, you need the most common tools (hammer, screwdriver, pliers). You can work anywhere with sufficient space (balcony, room, hallway, garage, etc.). No helpers or outside specialists are required.

The assembly is carried out in the following order:

Legs can be attached to the base, which will increase the stability when cutting the foam with a string.

How to choose a cutting wire

A suitable cutter can be made from nichrome wire (X20H80), which is used in the construction of most household appliances as a heating element. In terms of mechanical characteristics, nichrome is comparable to conventional steel, while it has a high resistivity and a heating limit up to temperatures of +1200 ºC. Wire up to 10 mm in diameter is available for making cutting devices.

Precise and smooth threading of foam is possible when the cutting line is heated to a temperature that is two to three times higher than the melting threshold (+270 ºC). It should be borne in mind that such a process involves the consumption of energy and the absorption of heat by the material itself in proportion to its density. Therefore, for efficient and safe cutting, it is necessary to select a wire of suitable thickness to prevent metal melting at maximum heating.

Calculation and preparation of the electrical part

For the safe operation of the device, it is necessary to correctly mount the conductive elements that are connected to the power source through the captive terminals. AC or DC can be used to cut the material. The power of the source is calculated based on the fact that for effective cutting of 10 mm wire, up to 2.5 W will be needed (for 500 mm - 125 V).

The voltage is proportional to the resistance and is calculated using formulas or tables. But on average, with a wire diameter of 0.8 mm, a length of 500 mm and a resistance of 2.2 Ohm, a current source with a voltage of 12 V with a load current of 12 A. current.

Electricity sources and connection diagram

Safe cutting is ensured by connecting to a regular household 220 V network through a car transformer. To adjust the voltage in the single primary winding, a knob is provided with which the graphite wheel is moved and the voltage is removed from the corresponding section. This parameter can be changed in the range from 0 to 240 V. The connection to the power supply is made through the terminal box.

When connecting a homemade foam cutting machine to the mains, you need to make sure that the phase does not fall on the common wire. All necessary parameters and wiring diagram can be found on the transformer housing. Before connecting to the network, you need to check the operation of the device using a multimeter.

A simpler way to apply current to the wire is to use conventional step-down transformers with secondary taps. In this case no need to select the voltage valuebecause this value is always constant and sufficient to heat the wire to the desired temperature. You can select the desired value during the initial configuration of the transformer by providing a certain number of winding turns in the circuit.

You can also heat the wire for cutting the foam using household appliances. In this case, the following nuances are taken into account:

It should be borne in mind that the cutting tool will be hot immediately when energized, so it should not be touched to check the temperature.

To make a thermal knife for polystyrene or foam rubber, it does not take a lot of time and effort. For this, a wire of almost any diameter is suitable, but with unknown parameters (diameter, resistance), the power must be increased gradually, first connecting low-power current sources. Reliable isolation of the contacts and control of the phase position, which cannot be connected to the wire, are of great importance.

Polyfoam is a wonderful material used in many areas of construction and decoration. With its help, they equip hydro and thermal insulation, create decorative ceiling coverings, baguettes and much more. For all its versatility, it is also cheap. The only problem that arises while working with it is cutting.

Cutting Styrofoam: DIY Machine

Cutting the foam yourself so that you get a clean and even cut is extremely difficult. It crumbles and bursts if you use a saw, even a blade or razor does not solve the problem.

Hot metal can be a solution, but how do you use it at home? Build a DIY Styrofoam Cutting Machine!

Method number 1.

To implement this undertaking you will need:

• table, it is better if each of its sides is at least 2 m;
• metal springs with low current resistance;
• a transformer that converts current from 220 to 24 Volts;
• high resistance string, if there is an old heater, remove from it.

You will also need a string adjuster. Use a pair of beams as it. A cutting string with a holder will move between them.

A transformer is not necessary in every case. It depends on what material the string is made of. If it is chrome-plated, a current of 220 volts is considered acceptable. But, working with such a discharge, safety rules should be strictly observed, otherwise the case may end sadly.

If you work with a 24 volt discharge, then there is no danger to life and health. It is simply not perceptible, and in case of defeat, you just need to rinse the affected area with water.

It should also be remembered that when cutting foam with hot metal, toxic vapors are released, so it is imperative to use a protective mask and ventilate the room well, otherwise poisoning will be ensured. And the best thing, in general, is to work on the street, but this is possible if you have your own yard.

In order to make it easier to assemble a foam cutting machine from the above materials, the following is a schematic drawing:

Method number 2.

In the absence of a suitable table, a chipboard sheet, plywood, board is quite suitable as a basis for the device.

The sequence for assembling a homemade machine:

1. Attach the nichrome wire to the springs, put the springs on the M4 screws, and screw them, in turn, into special racks.

2. Press the metal racks into the tabletop, chipboard, or any other surface chosen as a base in advance. The height of the post and the thickness of the base depend on the needs of the machine owner. If the slab is 1.8 cm thick and the stand is 2.8 cm high, then when fully screwed in, the screw will not go through the base, and when completely unscrewed, it will be able to cut 5 cm thick foam.

3. If a thicker thread is required in the future, the short screws will need to be removed and the longer ones screwed in their place.

4. To press in, drill a hole in the base. Its diameter should be less than the diameter of the rack by half a millimeter. Drive the racks into the holes with a hammer, but before that, to make this procedure easier for yourself, sandpaper the sharp edges of the ends.

5. Before screwing the screw into the rack, cut a groove under its very head. To do this, clamp its end with a screwdriver, and attach a thin file under the head and turn on the rotation. This groove is needed in order to fix the wire in one position, which otherwise can move during adjustment.

6. To prevent the wire from sagging, lengthening due to heat, attach it first to the springs, and then to the screws.

7. After all fasteners are ready, fix the nichrome wire. To make the contact between it and the conductive wire reliable, use the "crimp twist" method of attachment. The copper wire must have a cross section of at least 1.45 sq. Mm.

8. Strip the insulation from the ends of the wires by about 2 cm. Wrap the copper conductors around the wire where it is attached to the spring. Hold the end of the wire with pliers and wrap it around the conductor. Thanks to such winding, the contact between the wire and the conductive wire will have a large area, and when the machine is running, the joints will not get hot.

9. To be able to adjust the cutting thickness of the material, make a loop of the conductive conductors. And so that the wires do not get confused under your hands while using the machine, make holes in the base, pass the interfering piece through them and attach to the back of the surface with staples.

10. The wires are best folded together and twisted into a loose bundle. This way they won't get confused.

11. At the ends of the wires, solder the slip-on terminals to connect them to the power supply.

The device designed according to the above instructions will be quite enough for home use. In addition, it can be used as a machine for shaped cutting of foam.

Keep the material moving at medium speed while cutting. If you move the foam very quickly, then it will crumble in the same way as when cutting with a saw. If, on the contrary, move it very slowly, the edges of the cut shape will melt.

If the foam is required to insulate the house during construction, then it is better to purchase a thicker one. Due to its simple manufacture and low demand, such material is much cheaper than thin material.

If a Mayak stereo tape recorder has been lying around in the attic since Soviet times, then do not buy a transformer, but take it from it. It is just right, because supplies a voltage of 24 volts.

In the case when work is carried out in the absence of electricity, connect three crowns of 9 volts to each other and use them. Thus, the device will be able to function for 30-40 minutes.

But it is strictly forbidden to use autoaccumulators for this purpose. Despite the low voltage, they have a very high amperage, which can burn the string and it will simply burst. This is in a good scenario, and in a bad scenario, it will splash with red-hot metal.

The choice of foam for arranging thermal insulation

There is a special foam designed specifically for the insulation of facades. The packaging usually has a corresponding marking in the form of the letter "F". It has a high, in comparison with conventional material, density and is resistant to mechanical stress. It springs well, making it difficult to break.

When cutting foam, the string should not be set below 50 mm for thermal insulation. The fact is that a thinner material will not be effective enough, and when wet, it will generally lose most of its wonderful properties. At high humidity, such insulation will be permeable to cold air, like ordinary brickwork.

Use a mineral wool board as an additional material for thermal insulation. In addition to the properties mentioned, it has another important advantage - it will not burn in the event of a fire.

Foam cutting machine, video:

recn.ru

DIY Styrofoam Cutting Machine: How to Cut Styrofoam

The issue of home insulation is very relevant these days. Facade cladding with foam is one of the most popular types of insulation. And this is very reasonable, since the process of such insulation is simple and straightforward, and all the necessary materials are always available for sale.

But everyone knows that it is very convenient to glue foam on a flat wall. With any method of gluing foam on the wall: on dry mix glue, on foam or foam glue, it is always very important that the foam sheet adheres tightly to the wall and does not create air gaps.

If the wall is flat, then no questions arise. But, unfortunately, the walls of old houses do not differ in ideal evenness. Yes, and different design features of the structure sometimes create drops in the plane of the wall.

Partially this disadvantage can be leveled by laying the foam on a thicker layer of glue. But the maximum permissible thickness of the glue layer often cannot cover the magnitude of the differences in the plane of the walls. In addition, too large differences lead to unnecessary waste of glue.

The next way out of the situation remains - trimming the foam by thickness. But doing this with a hacksaw is very inconvenient and takes a long time, especially if you need to cut a large amount of foam. In addition, a large amount of debris in the form of foam balls is generated during cutting. And the surface is uneven and the accuracy of such cutting is very conditional.

In order to quickly and evenly cut the foam to the desired thickness, you can use a foam cutting machine. This device can be made independently, absolutely with your own hands.

The principle of operation and construction of the foam cutting machine

The principle of operation of the machine is based on the fact that the foam melts easily under the influence of temperature. Thus, if a thin heated wire is drawn over it, it is easily cut, while forming a perfectly flat smooth surface.

For the manufacture of the machine you need the following components:

• LATR (laboratory autotransformer) or car battery;
• nichrome thread;
• racks for fastening nichrome thread;
• spring (1-2 pcs.);
• tabletop board;
• copper wire.

A nichrome thread (spiral) is used as a cutting object. It can either be bought in a store or removed from old household appliances in which they were used as filaments (hair dryer, for example). The coil thickness can be 0.5-1 mm. The most optimal thickness is 0.7 mm. The length depends on the width of the foam to be cut.

An important element of the device for cutting foam plastic is LATR. But if it is not there, then it can be done using an old transformer and a device for charging car batteries.

You can also use a computer power supply, which uses wires giving 12 W (yellow and black) to connect to the spiral.

For the operation of such a machine, it is enough to have an output voltage of 6-12 W.

The length and thickness of the filament must be properly adjusted to match the voltage. If the thread gets too hot, it can break. Well, if the thread heats up slightly, then cutting will be slow.

A car battery can also be used as a power source. It can be used in conditions if there is no electricity on the site.

A machine for cutting foam in the field. Connection to car battery.

For different tasks, you can make different designs of the foam cutting device.

Basically, these devices will differ in the length of the spiral. To cut the foam into bars, you need a short spiral length.

You can install two spirals and cut the sheet into several bars in one pass.

Two spirals cut the sheet into three pieces in one pass. The support is packed with guides for even feeding the foam.

But, as a last resort, the foam can be cut into bars with a hacksaw. It is much more difficult to cut the polystyrene to the thickness, and even to the given size. Therefore, we will consider how to make a machine for cutting foam plastic in width.

Step-by-step instructions for self-manufacturing of the machine and cutting foam

Step 1. Worktop preparation. You can take any piece of chipboard of the required size as the tabletop of the device for cutting foam with your own hands. The surface on which the foam will move must be smooth. Holes are drilled in the countertop for the uprights. It is convenient to use metal pins with a thread with a diameter of 10-12 mm as stands. The height of the racks should correspond to the thickness of the foam sheets plus a headroom. The pin is fixed with nuts.

To give the structure stability, bars are attached to the bottom of the tabletop, which will also serve for the safe passage of the electrical wire.

Step 2. Connecting the current supply wires. From the bottom under the table top, the wires are connected to metal rods: the wire is wound on the lower end of the pin and pressed with a bolt.

The other end of the wires must be connected to a power source depending on the method chosen. The best connection is a plug that will connect to the LATER socket. Connection is possible through self-clamping terminals, as well as by twisting and soldering. It depends on the selected power source.

In any case, the connection must be made in accordance with the rules for working with electrical installations and devices, be convenient for work and safe during operation.

Step 3. Securing the nichrome spiral. Nichrome spiral is fixed between two posts. A spring is attached to one end of the spiral (there may be two of them).

The spring is needed in order to pull the nichrome thread during operation. The fact is that when heated, the nichrome thread lengthens and sags. A thread in this state will not give a high-quality cut. Therefore, the thread is fixed in an initially stressed state so that the spring is slightly stretched.

To attach the nichrome thread to the pin, washers with an inner diameter slightly larger than the diameter of the pin are used. A small hole is made in the washer for attaching the spiral itself. A small sharpening is also done on the side of the inner diameter so that the washer can be fixed on the thread of the pin.

A spring with a spiral attached to it is inserted into one washer and put on the first pin. The second washer is put on the second pin and a nichrome spiral is threaded into the drilled hole. Then it is pulled so that the spring is stretched, and fixed.

Step 4. Cutting the foam. To dissolve the foam sheet into two sheets of a given size, the spiral is set to the desired height. The required distance is measured with a ruler.

Then the machine is connected to a power source. The thread heats up and now you can cut the foam, smoothly moving it forward along the table top.

The cutting speed depends on the filament filament temperature, which in turn depends on the applied voltage and the thickness of the filament itself. You should not try to apply more voltage to achieve high speed, because this can cause the filament to burn out quickly. Here, empirically, a balance must be found between tension, thickness and length of the thread. The thread should not be overheated during operation. When heated, it turns red or scarlet. But it should not turn white - this indicates that the thread is overheating and that it is desirable to reduce the voltage, otherwise the thread will not last long in this mode. Of course, infinitely variable adjustments are easy if LATER is available. But if it is not there, then a laboratory power supply can also be made from a computer power supply, there is more information in the video below. After you have made this foam cutting machine with your own hands, you need to make sure that the machine is safe.

It must be remembered that all measures must comply with safety measures for working with electrical appliances. The power supply must be grounded and all connections must be carefully insulated. All work on the assembly of the machine must be carried out with de-energized wires. The machine is only connected to the mains when working with foam. After work, it must be turned off immediately. While working with the machine, you should avoid touching metal parts and the nichrome thread itself.

Step 4. Cutting the foam at an angle. Sometimes it becomes necessary to cut the foam in such a way that one side is higher and the other is lower.

For this, the spiral is set at a slope with the required parameters. In this way, foam sheets of various sections can be obtained.

Useful video

o-builder.ru

Homemade foam cutting machine Design, calculation, electrical diagram

Heat and soundproof building materials on the market are presented in a wide range, this is foamed polyethylene, mineral and basalt wool and many others. But the most common for insulation and sound insulation is extruded polystyrene foam and polystyrene, due to its high physical and chemical properties, ease of installation, low weight and low cost. Polyfoam has a low coefficient of thermal conductivity, high coefficient of sound absorption, is resistant to water, weak acids, alkalis. Foam plastic is resistant to ambient temperatures, from the lowest possible to 90˚С. Even after decades, the foam does not change its physical and chemical properties. Polyfoam also has sufficient mechanical strength.

Polyfoam also has very important properties, it is fire resistance (when exposed to fire, the foam does not smolder like wood), environmental friendliness (since the foam is made of styrene, even food products can be stored in containers from it). Fungi and bacterial foci do not appear on the foam. Almost ideal material for insulation and sound insulation in the construction and renovation of houses, apartments, garages, and even packaging for storing food.

In building materials stores, polystyrene is sold in the form of plates of different thicknesses and sizes. During repairs, foam sheets of different thicknesses are often needed. With a foam cutting machine, you can always cut foam sheets of the required thickness from a thick plate. The machine also allows shaped foam packaging from household appliances to be turned into plates, as in the photo above, and successfully cut through thick sheets of foam for furniture repair.

How easily styrofoam is cut on a homemade machine is clearly demonstrated by a video clip.

If you want to make a machine for cutting foam and foam rubber, many are stopped by the difficulty of organizing the supply of voltage to heat the nichrome string to the desired temperature. This obstacle is surmountable if you understand the physics of the issue.

Construction of the foam cutting machine

The basis of the device for cutting the foam was a sheet of chipboard (chipboard). The size of the slab should be taken based on the width of the foam plates that are planned to be cut. I used a furniture door measuring 40 × 60 cm.With this size of the base, it will be possible to cut foam sheets up to 50 cm wide.The base can be made from a sheet of plywood, a wide board, fix the cutting string directly on the work table or workbench.

Pulling a nichrome string between two nails is the limit of home craftsman's laziness, so I implemented the simplest design that provides reliable fixation and smooth adjustment of the height of the string during cutting above the surface of the machine base.

The ends of the nichrome wire are fastened to the springs, dressed on M4 screws. The screws themselves are screwed into metal racks pressed into the base of the machine. With a base thickness of 18 mm, I selected a metal stand 28 mm long, so that when fully screwed in, the screw does not go beyond the bottom side of the base, and with the maximum unscrewed state, it provides a foam cut thickness of 50 mm. If you need to cut sheets of foam or foam rubber of greater thickness, then it will be enough to replace the screws with longer ones.

To press the post into the base, first a hole is drilled into it, with a diameter of 0.5 mm less than the outer diameter of the post. In order for the racks to be easily hammered into the base, the sharp edges from the ends were removed on an emery column.

Before tightening the screw into the rack, a groove was made at its head so that the nichrome wire during adjustment could not move arbitrarily, but took the required position.

To make a groove in a screw, you first need to protect its thread from deformation by putting on a plastic tube or wrap it with thick paper. Then clamp the drill in the chuck, turn on the drill and attach a narrow file. The groove will be ready in a minute.

To prevent sagging of the nichrome wire due to elongation during heating, it is fixed to the screws through springs.

The spring from a computer monitor, used to tension the grounding conductors on the CRT, turned out to be suitable. The spring was longer than required, I had to make two of it, for each side of the wire attachment.

After preparing all the fasteners, you can fix the nichrome wire. Since the current is consumed during operation is significant, about 10 A, then for reliable contact of the current supply wire with the nichrome wire, I used the method of fastening by twisting with compression. The thickness of the copper wire at a current of 10 A must be taken with a cross section of at least 1.45 mm2. You can choose the cross-section of the wire for connecting nichrome wire from the table. I had at my disposal a wire with a cross section of about 1 mm2. Therefore, each of the wires had to be made from two with a cross section of 1 mm2, connected in parallel.

After stripping the insulation from the ends of the wires for a length of about 20 mm, copper conductors are wound onto a string of nichrome wire at the point of its attachment to the spring. Then, holding the nichrome wire by the loop with pliers, the wrapping made of the copper wire is wrapped around the free end of the nichrome wire in the opposite direction.

This method of connecting the current-carrying copper wire with a nichrome wire will provide a large contact area and exclude strong heating at the junction during the operation of the foam cutting machine. This was confirmed by practice, after prolonged cutting of the foam, the PVC sheath of the current-carrying wire did not melt, the copper wire in the connection zone did not change its color.

For the possibility of adjusting the thickness of cutting the foam on the device, the outlet of the current-carrying conductors is made with a loop. So that the wires do not interfere with the work, they are passed through the holes in the base and fixed on the back side with brackets. At the corners of the base, the same brackets are nailed as legs.

The lead wires are twisted together so as not to get tangled. At the ends of the wires for connecting to the power source, captive terminals are soldered.

Nichrome wire is not much different in appearance from steel wire, but it is made of an alloy of chromium and nickel. The most widespread wire of the Х20Н80 brand, containing 20% \u200b\u200bchromium and 80% nickel. However, unlike steel or copper wire, nichrome wire has a higher resistivity and withstands, while maintaining high mechanical strength, heating temperatures up to 1200˚С. Nichrome wire is available in diameters from 0.1 mm to 10 mm.

Nichrome wire is widely used as heating elements in household and industrial products such as electric hair dryers, iron, hot plates, ray heaters, soldering irons, water heaters, and even electric kettles. And this is not a complete list. The so-called heaters of the TEN type are also made of nichrome wire, only the spiral is placed in a metal tube, which is filled with quartz sand for insulation and heat transfer from the spiral to the tube walls. The list of devices is not accidental, it's just that you can take nichrome wire from a failed heating element for making a machine, of course, if it did not have time to burn out from long work.

Cutting foam on the machine consists in melting it along the line of passage, heated nichrome wire. The melting point of the foam is about 270 ° C. in order for the foam to melt upon contact with the wire, its temperature must be several times higher, since heat will be consumed not only for melting, but also due to thermal conductivity, absorbed by the foam itself, reducing the temperature of the wire. The amount of heat absorbed by the foam will directly depend on its density. The denser the foam, the more heat will be required.

From the above, it follows that, depending on the density of the foam, for its cutting it is necessary to choose a wire of the appropriate diameter so that the nichrome wire does not melt from the heat released on it. The higher the density of the foam, the larger the diameter of the nichrome wire. It is worth noting that the machine on which the wire for cutting dense foam is installed will successfully cut and loose, only it will need to be promoted faster.

The length of the nichrome wire for the device is selected based on the dimensions of the foam plates intended for cutting, and does not depend on the density of the foam.

As a result of the experiments, it was determined that for effective cutting of foam plastic, the power that must be supplied per unit of wire length should be in the range of 1.5-2.5 W per centimeter of wire length, for this mode of operation, nichrome wire with a diameter of 0 , 5-0.8 mm. It generates enough heat to quickly cut foam of any density, while maintaining its mechanical strength. Therefore, for the manufacture of a machine for cutting foam, a nichrome wire with a diameter of 0.8 mm was used.

Calculation of the parameters of the power source for heating the wire

It should be noted that for heating the nichrome wire of the foam cutting machine, a power source of both alternating current and direct current is suitable.

Taking into account that no more than 2.5 watts and a wire length of 50 cm must be allocated per centimeter of wire length, the power of the power supply can be calculated. To do this, you need to multiply the amount of power released by the length of the wire. As a result, it turns out that a 125 W power supply is needed to heat the wire of the foam cutting machine.

Now you need to determine the voltage value of the power supply. To do this, you need to know the resistance of the nichrome wire of the foam cutting machine.

Wire resistance can be calculated from the specific resistance (resistance of one meter of wire). Specific resistance of wire made of nichrome grade Х20Н80 is given in the table. For other brands of nichrome, the values \u200b\u200bdiffer slightly.

As can be seen from the table, for a wire with a diameter of 0.8 mm, the resistivity is 2.2 Ohm, therefore, a nichrome wire 50 cm long, which was selected for the foam plastic cutting machine, will have a resistance of 1.1 Ohm. If you choose a wire with a diameter of 0.5 mm, then the resistance of a piece of wire 50 cm long will be 2.8 ohms.

Using the transformed formulas of Ohm and Joule-Lenz's laws, we obtain a formula for calculating the supply voltage for a foam cutting machine. The supply voltage will be equal to the root of the product of the power consumption and the resistance of the wire. As a result of calculations, it turns out that you need a power source with a voltage of 11.7 V. In this case, the current consumption from the source will be 11.7 A. In order to find the current value, you need to divide the power consumption by the voltage value. Dividing 125 W by 11.7 V, we get a current of 11.7 A.

As a result of the calculations, it was determined that to heat the nichrome wire of the foam cutting machine, an AC or DC power source is required, delivering a voltage of 11.7 V and providing a load current of 12 A.

When decreasing or increasing the length of the wire, the voltage of the power source will need to be proportionally reduced or increased accordingly. In this case, the current value will not change.

The calculation performed is an estimate, since the transition resistance at the points of connection of the wires and the resistance of the current-carrying conductors are not taken into account. Therefore, the optimal mode of heating the wire ultimately has to be set directly when cutting the foam on the device.

Electrical diagram of the power supply of the foam cutting machine

You can apply the supply voltage to the nichrome thread of the foam cutting machine using several schemes.

Diagram of a machine for cutting foam using LATR

The simplest version of the power supply for the foam cutting machine is an autotransformer with the ability to smoothly adjust the output voltage. But this circuit has a significant drawback, it does not have a galvanic isolation from the mains supply, since the LATR output is directly connected to the mains. Therefore, when using LATR, it is necessary to connect it in such a way that the common wire is connected to the neutral wire of the supply network.

Wiring diagram for connecting the nichrome spiral of the foam cutting machine to LATR.

What is LATR and how it works

The industry produces laboratory autotransformers, which are called LATR (controlled laboratory autotransformer). They are connected directly to a 220 V household power supply and, depending on the type of LATR, are designed for different load currents.

LATR is a toroidal transformer with one primary winding, along the turns of which, when the handle located on top is rotated, a graphite wheel moves, making it possible to remove voltage from any section of the winding. In this way, the voltage at the LATR output can be changed from 0 to 240 V.

The wires are connected to LATR using a terminal block, on which its electrical circuit is drawn and the inscriptions "Network" and "Load" are applied. A cord with a plug is connected to the “Network” terminals to connect to a household network. A product is connected to the “Load” terminals, which must be powered with a voltage different from the household power supply.

Attention! One of the mains wires, the lower terminals in the photo, is connected directly to one of the load wires. Thus, if a phase falls on the lower terminal, then touching this circuit will be dangerous for a person.

Therefore, in the case of using LATR for heating the nichrome wire of a foam plastic cutting machine without an isolation transformer, it is imperative to check the absence of a phase on the common wire with the phase indicator. If there is a phase on it, remove the LATR power plug from the socket and, turning it 180 degrees, insert it again. Recheck the bottom wire for phase presence.

Usually on the LATR body there is a label, which contains data on its load capacity. On the LATR, which is shown in the photograph, the label is installed directly on the adjustment knob.

It follows from the label that this is a LATR type LOSN, the output voltage can be adjusted in the range from 5 to 240 volts, the maximum load current is 2 A.

If the rated current does not exceed 8 A, then it is quite possible to feed the nichrome wire through the LATR type RNO 250-2.

This LATR allows you to connect a load with a current consumption of up to 8 A, but given the short-term operation of the device for cutting foam, it will fully withstand the load current and 10 A.

Before using LATR as a power source, it is necessary to check its operability. To do this, connect the power cord to the “Network” terminals of LATR, and to the “Load” terminals, a multimeter or a pointer tester, included in the AC voltage measurement mode, to a limit of at least 250 V. Set the LATR voltage adjustment knob to the minimum voltage position. Insert the plug into the socket.

By slowly turning the LATR knob clockwise, make sure that the output voltage increases. Return the LATR knob to the zero position. Remove the plug from the network and connect the wires coming from the nichrome thread to the “Load” terminals. Insert the plug of the power cord into the socket and with the phase indicator check that there is no phase on the nichrome wire. Having dealt with the phase, it is possible, by slowly turning the LATR knob, to apply voltage to the nichrome wire. It should be borne in mind that the wire heats up gradually, within a few seconds.

Attention! It is strictly forbidden to touch the wire with your hand to check the degree of its heating when the supply voltage is applied to it! The temperature of the wire is very high and may burn!

When the wire heats up to a slightly noticeable glow, you can start cutting the foam on the machine.

Diagram of a machine for cutting foam using a LATR step-down transformer

If the value of the current consumed by the nichrome wire of the foam cutting machine is greater than the LATR can provide, then it will be necessary to additionally turn on the step-down transformer after it according to the electrical diagram below.

As you can see, unlike the previous circuit, the mains winding of the power transformer is connected to the LATR output, the nichrome spiral is connected to the secondary output winding of the transformer. In this circuit, thanks to the decoupling step-down transformer, the nichrome coil is not galvanically connected to the mains and therefore safe for operation. In addition, it became possible to more smoothly adjust the output voltage and, therefore, more accurately set the cutting temperature of the foam on the machine.

The power of the transformer and the voltage on its secondary winding are taken on the basis of calculations performed according to the above method. For example, for the proposed design of a machine for cutting foam, with a nichrome wire diameter of 0.8 mm and a length of 50 cm, a LATR with an output current of 2 A with a 150 W step-down transformer connected after it with a secondary voltage of 12 V.

A transformer with taps in the secondary winding can be used to power the nichrome spiral of the foam cutting machine. This is the simplest, most reliable and safest option, especially if the foam cutting machine will be used regularly. Indeed, when cutting polystyrene on a device, it is not necessary to regulate the heating temperature of the nichrome wire. The temperature is selected once when setting up the machine. Therefore, having selected the required voltage, the wires from the terminals of the nichrome wire are soldered to the terminals of the secondary winding of the transformer forever.

Despite the simplicity and reliability of this circuit, there are no standard ready-made transformers with taps, and even for the required voltage. You will have to find a suitable transformer for voltage and current on the secondary winding and unwind the extra turns. You can disassemble the transformer and rewind part of the secondary winding, rewind it, but with taps. But this job requires knowledge and experience.

Diagram of a machine for cutting foam plastic using a step-down transformer and current-limiting capacitors

It is possible to establish a stable output current from the secondary winding of the transformer using ordinary capacitors included in the primary winding of the transformer.

The capacitor must be rated for a voltage of at least 300 V and have a capacity, depending on the type of transformer and the current consumption of the nichrome spiral, of the order of 50 μF. On this principle of stabilizing the current on the secondary winding, I have developed a charger circuit for car batteries. The transformer must be of adequate power and have a 10% voltage margin.

Diagram of a machine for cutting foam plastic using a step-down transformer and a thyristor power regulator

Another, somewhat unusual circuit of the nichrome wire heating temperature controller, using a thyristor. It is similar to the adjustment using a LATR with a transformer, but small. The classic thyristor regulator circuit is not suitable for this circuit, since it distorts the shape of the sinusoidal current.

Therefore, a special thyristor regulator circuit is needed that produces a sinusoidal signal at the output and is designed to work with an inductive load.

It is also possible to turn on the thyristor regulator after the secondary winding of the transformer. In this case, when choosing a regulator circuit, it should be taken into account that it must be designed for the current required to heat the nichrome wire.

Diagram of a machine for cutting foam plastic using any electrical appliances

If none of the above electrical circuits for heating the nichrome wire for the foam plastic cutting device can be implemented, then I propose a non-standard circuit for heating it.

When connecting any electrical appliance, it consumes current from the mains. The amount of current directly depends on the power of the appliance. The more power, the more current will flow through the wires. The resistance of a piece of nichrome wire of the machine for cutting polystyrene is slightly higher than the resistance of copper wires and, therefore, the inclusion of the machine in the rupture of one of the wires of the electrical appliance will not affect its work, and the nichrome wire will heat up. This is what you can use.

When using the connection of the machine for cutting foam according to this scheme, it is imperative to make sure that the nichrome wire is not connected directly to the phase wire of the mains. Physically, the connection is best done using an adapter like the one described for measuring current consumption.

Suitable for work in the circuit of continuous electrical appliances, such as a heater, vacuum cleaner. You can estimate the current consumed by electrical appliances according to the table on the website page "Choosing the cross-section of the cable wire for wiring".

If the electrical parameters of the nichrome wire are not known, then you must first try to connect a low-power electrical appliance, for example a 200 W electric light bulb (a current of about 1 A will flow), then a 1 kW heater (4.5 A), and so increase the power of the connected devices while the nichrome the wire of the foam cutting machine will not heat up to the desired temperature. Electrical appliances can also be connected in parallel.

The disadvantages of the last scheme for connecting a nichrome spiral of a machine for cutting foam plastic should include the need to determine the phase for the correct connection and low efficiency (efficiency), kilowatts of electricity will go uselessly.

ydoma.info

Do-it-yourself machines for cutting foam plastic (drawings, video)

The foam cutting machine is an important piece of equipment for many businesses and home workshops. With their help, the production of various blanks used in construction, repair, decoration, interior design, etc. is carried out.

Photo of the machine for cutting foam

If you study the range of factory models of machines for cutting foam plastic or just PSA, then there are several types:

• Mobile. Such PSAs are more likely to resemble an ordinary knife designed to work on foam with your own hands. A variety of simple workpieces can be made with a mobile machine. Quite often found in everyday life when processing foam, expanded polystyrene;
• Machines for transverse and horizontal processing. These PSA are cut in a certain direction, that is, it is problematic to achieve complex shapes. But the machine provides highly efficient production, large materials are cut;
• CNC machines. SRP, equipped with a CNC module, are modern models of machines for processing expanded polystyrene, expanded plastic. With its help, you can make the most diverse in terms of parameters, complexity and configuration of machines, 3d models. The current furniture, repair and construction production is not complete without the use of PSA with CNC.

Schematic drawing of a machine for cutting foam

If you want to buy a PSA or make it yourself, first you need to understand the features of the device functioning.

• Most types of foam machines operate on a single principle;
• The cutting part of the machine heats up, affects the material being processed;
• The cutting element moves according to the drawings;
• The process is similar to passing a hot knife through oil, that is, the process is easy, with minimal damage to the foam or expanded polystyrene;
• The simplest model of the machine has one cutting line. Such an installation is easy to do with your own hands, having an appropriate drawing at your disposal;
• To work with complex 3d shapes, to make high-precision cuts, an SRP with a CNC module is used. The machine itself can have up to 6 cutting strings;
• The advantage of the machine operation is that additional processing of edges is not required due to the clean cut. This simplifies production and minimizes the cost of finishing parts.

Features of the device

• If you want to make a foam cutter with your own hands, this can be done in two ways - vertical and horizontal cut of the foam sheet;
• To make a vertical cut, the cutting line is set perpendicular to the work table;
• For a horizontal cut, you need to make an appropriate structure, the opposite of the first example;
• To get an even, neat cut, you need a competent drawing and template for subsequent processing;
• The drawing is widely represented on the network, which allows anyone who wants to make a machine at their own discretion, based on personal needs or materials available for assembling the PSA;
• It is recommended to use nichrome thread as a cutting element. Almost every drawing provides for its application;
• For the processing of complex parts, obtaining 3d models, the current production of machine tools has reached a high level. Special models of CNC units are widely used, designed specifically for shaped cutting. The workpiece is processed in several projections at once. Due to this equipment, it is possible to establish the production of models of cars, people, aircraft, animals and much more. Moreover, in fact, 3d products are obtained that accurately repeat all the bends, lines, configurations of the copied product.

Do-it-yourself machine

The production of special machines for cutting foam plastic is put on an active stream. At the same time, the cost of the equipment seems high for many potential buyers. In addition, having the opportunity to assemble a foam cutting machine without much help, with their own hands, many simply give up the idea of \u200b\u200bbuying. The approximate price of a factory machine is from 40 thousand rubles. But there are models that cost 100 thousand rubles and more.

Yes, for that kind of money, you can get a great foam cutting machine equipped with a CNC module. The CNC machine is much superior to homemade simple devices. At the same time, not everyone has a real need for CNC and automated cutting of foam. Therefore, we will give an example of how you can make an excellent unit for processing expanded polystyrene or polystyrene with your own hands. Strengthening skills with video lessons will not be superfluous.

1. Drawing. It is not necessary to use the drawing specifically for this model of the machine. It is not needed here, since the construction is quite simple. But for clarity, you can draw the drawing yourself, rely on the selected parameters. Another option is to choose a drawing for a more serious installation. It all depends on what you want out of your foam cutter.
2. Select or assemble a table on which the EPS cutting operations will be performed. The surface should be covered with thermal insulation or electrical material. In this component, the polyamide film has proven itself well.
3. Attach the insulator to the center of the long side of the work surface. One at each end. Ceramic or glass elements can be used as insulators. Between these components of the structure, you will then pull a thread that will act as a cutting tool.
4. Choose your line. If you have an old hotplate, unnecessary soldering iron or iron, you will find nichrome thread inside them. She has enough power.
5. Remove the spiral from the tool, gently straighten it to get a straight thread.
6. It is not recommended to use nichrome threads for a homemade machine, the thickness of which is more than 0.5 millimeters.
7. Be sure to connect the filament to the network through a rheostat or step-down transformer. This will save your main working element of the machine from burning.
8. A nichrome line is connected to a coil on an insulating material. An electric cable is connected to the line, through which power will be supplied to the machine. Try to ensure that the contact between the electric cable and the thread is of the highest quality.
9. Under the table, pull the thread to another insulator and pass through it. The end of the thread will hang from the insulator, so a weight should be provided here. The weight of the load determines the tension of the heated filament when processing foam. Here you have to play a little to determine the optimal parameters of the weight. Movable sliding fixation is the most beneficial when creating such a machine with your own hands. This is due to the fact that this way you get a better and cleaner cut line, you can adjust the position of the thread as needed.
10. Near the second insulation coil, a second electrical cable is mounted to the thread, which goes to the rheostat, is connected to the slider terminal.

It is allowed to start the machine only after the slider has been set to the maximum resistance level. If this is not done, literally immediately after turning on your thread will burn out, you will have to look for a new one.

The power of the unit depends on the parameters of the current and the thickness of the thread used. The only drawback of a homemade foam machine is that when heated, the material emits an unpleasant odor and harmful substances. Therefore, it is strongly recommended to use the machine only where there is an effective ventilation system.

During construction and finishing work, the question arises of how to cut the foam so that it does not crumble. For this, special tools and techniques are used, which are selected based on the dimensions of the foam board. These cutters can be purchased from a store or you can make your own. To make a tool with your own hands, you do not need special knowledge or skills.

DIY nichrome cutter

The foam is cut with a wire heated to + 120 ... + 150 ° C and melting material. Thanks to this, the cut is even, and the foam does not crumble. On such devices, a nichrome thread is installed through which electricity is passed. You can make a simple cutter with your own hands. It differs from the machine in portability and compactness, therefore, the heating temperature of the nichrome wire cannot be regulated on it.

Required tools and materials

To make a cutter with nichrome wire for cutting foam, you will need the following tools and materials:

• a small wooden block;
• screwdriver and drill;
• 2 pencils;
• 2 pieces of copper wire;
• round-nose pliers;
• hot glue or PVA;
• insulating tape;
• battery connector;
• switch;
• 1 m of wires;
• soldering iron;
• nichrome thread.

The latter is sold in a radio parts store. It can also be taken from old heating elements from a hair dryer, boiler, boiler, etc.

Homemade Styrofoam Cutter

A homemade cutter is intended for minor jobs. It is not possible to cut the entire sheet of expanded polystyrene with them. To cut styrofoam at home, you must:

1. Make 2 holes in a wooden block 10-11 cm long. They should match the diameter of the pencils. You need to retreat from the edge by 1-1.5 cm. The recess should be slightly deeper than half of the bar to fix the pencils. Thanks to this distance, you can cut foam sheets of almost any thickness.
2. Glue both pencils into the holes with hot glue or PVA.
3. In each of the pencils, make a small hole on top for the copper wire.
4. Bend the copper wire with round-nose pliers so that small rings are formed at its ends. Then install in the holes in the pencils.
5. Glue the battery connector perpendicularly to a wooden block. Additionally, it will act as a handle.
6. Stick a switch on the block so that you can de-energize the string.
7. Then connect 2 wires to the connector. After that, connect to the switch, and then bring each to a separate pencil. To prevent the wire from sagging and interfering with work, it is fixed with electrical tape. To ensure a reliable connection quality, you need to solder the wires to the connector. The joints must be insulated with heat shrink tubing or electrical tape.
8. Remove the braid from the other end of each wire and screw it to the copper wire. Solder the connection.
9. Thread the nichrome thread into the copper wire rings and fasten to them. The string should be tight between the pencils. When heated, it stretches and sags a little. The tighter the tension, the less sag.
10. Insert the batteries into the connector and start cutting the foam sheets.

Thus, you can make a simple device for cutting foam with your own hands. And another option for making a machine, see the video:

DIY Styrofoam Cutting Machine

Cutting machines are more convenient in that the cutting thread is fixed in them and only the foam needs to be moved. This improves the accuracy of the movements. During the manufacture, you will need the same tools and equipment as in the previous case.

First you need to make a table, which is a wooden base with small legs. The table must be level and smooth to prevent deformation of the foam. The dimensions of the base are arbitrarily selected. A bar is screwed perpendicularly to the tabletop, and a wooden crossbar is attached to it at an angle of 90 °. Then it is necessary to reinforce the structure with a jumper.

The angled ruler marks the place where the filament will go. If the surface is sufficiently level, this can be done with a plumb line. To do this, a self-tapping screw with a wide head is screwed into the end, and a thread with a load is screwed onto it. A hole with a diameter of 6 mm is drilled in the selected place. To prevent the string from burning the wood, a plate of textolite or metal is installed. Place the material flush with the surface.

A wire is threaded into the hole, the lower end of which is put on a self-tapping screw. The screw is screwed in next to the hole. The length of the coil should be such that it turns red when heated. Since the wire lengthens at high temperatures, a compensating spring must be used to avoid sagging. A spring is mounted on the upper self-tapping screw, and a nichrome thread is attached to it.

An energy source is connected to the ends of the filament, which can be a battery with a voltage of 11.7-12.4 V. To regulate this indicator, a thyristor regulator circuit is used. The regulator can be taken from an electric grinder. You can also control the voltage using a spiral on a polystyrene foam cutting machine.

This coil is mounted on a block of wood to which the upper edge of the filament is attached. It is connected to the wire in series. Its function is to lengthen the nichrome thread and, accordingly, reduce the stress. This can be achieved by changing the place of connection to the nichrome spiral. The smaller the distance, the more the thread heats up and the more the foam melts.

If a transformer is connected to the machine, it must be galvanically isolated. In this case, a transformer with taps must be used.

For smooth and even cuts, you need to make a guide rail. It is made from a bar or any other even material.

With the help of such a simple machine, you can cut the foam with your own hands. Additionally, you can make various devices. You can make a miter box during the repair with your own hands or a tray that will help you evenly cut the material at the right angles.

3D foam cutting technology

Expanded polystyrene products are widely used for marketing and decorative purposes. Logos of companies are made from expanded polystyrene, names, various figures, decorative elements, etc. are cut out. Therefore, 3D cutting has gained wide popularity. The use of foam allows you to save money and at the same time get a high-quality and durable product.

Volumetric cutting is carried out on special machines. They cut the material using long strings or a laser and allow you to shape the foam into any shape.

Shaped cutting of foam

Shaped cutting of expanded polystyrene is carried out on special machines. Some of them are equipped with CNC. When working on a machine, the thickness of the foam sheets does not matter. However, you can use a simple DIY cutter for easy cutting.