Cut the foam with a nichrome wire with your own hands. Do -it -yourself nichrome cutter

Foam cutting with nichrome

Among the favorite technologies of modelists, Phulast occupies an important place. It is easy to process, light and moderately durable. Whole foam wings of various densities are used in air combat models. A special cutter is required for their manufacture. Foam cutting. In fact, this is a nichrome wire warmed up under the influence of electric current.

Bonstructive solutions every modelist can make it himself. I want to tell how to decide on the parameters of the wire and the power supply.

How to choose diameter and voltage

The most important thing you need to know is the dependence of the current value on the diameter of the nichrome wire necessary to warm it up. The table contains data for a temperature of 700 degrees (polystyrene is melted at ~ 250 degrees Celsius).

Diameter, mm current, and
1.0 12.1
0.9 10.45
0.8 9.15
0.75 8.4
0.7 7.8
0.65 7.15
0.6 6.5
0.55 5.8
0.5 5.2
0.45 4.45
0.4 3.85
0.35 3.3
0.3 2.7
0.25 2.15
0.2 1.65
0.15 1.15
0.1 0.72

I have a 12V power supply and several pieces of nichrome of different diameters. Therefore, I will start from the tension. I would like to get a cutter about 50-60 cm long, so that it is convenient to cut the wings consoles.

DIY a thermal knife for SIP panels

Construction from SIP panels using Canadian technology gives a lot of advantages to the happy owners of the new home. However, everyone wants to give their project elegance, style, not limited to faceless rectangular constructions. This requires cutting panels, the formation of parts of a complex configuration.

If the project is ordered from the contractor, there will be no problems. But if the construction is carried out independently, special equipment will be required, in particular, the thermal cutter.

Cutting panels

SIP panel is easily modified. When the construction is carried out independently, cutting is as follows:

  • Two surfaces of the OSP panels are cut using an electrolobian or circular saw;
  • On the line of the cut, the part of the panels, which goes into consumption, is simply broken off.

The most important problem remains: to form a groove for the installation of a strainer.

To do this, often use grater, shirts or cutter, which simply in small portions remove the right amount of filler SIP panels.

At the same time, the work with your own hands is not difficult, but the construction site is littered, filled with small “snow” from the particles of the filler, which are constantly moving and difficult to remove.

What is the groove in SIP panels

To make a groove in SIP panels, there are two methods:

  • industrial, with the use of a cutting type cutter that removes the filler with knives, with forced waste removal;
  • Using heat treatment, a cutter is used, which carefully melts the filler and allows you to immediately form a groove of the desired depth.

Today, enough models are sold, you can buy a thermal knife that will be adjusted by power, temperature, and allow the formation of a groove of the desired depth. However, such a tool can be done with your own hands. The design of the knife is not difficult, so it is easy to repeat in a handicraft product.

How to make a thermal

The temperature knife should have the following functionality:

  • adjustment of the temperature of the cutting part;
  • Thermal must be allowed to regulate the depth of the groove;
  • The design should be such that the knife can be used without preliminary work after cutting SIP panels.

It is important to know: standard sig of panels

Despite the apparent complexity of the task, making such a thermal is easy enough. With it, cutting SIP panels with your own hands will be simple and fast. To create a device you will need:

  • Two strips of hard steel or fiberglass of small thickness. Their strength depends on the necessary depth of the groove that is required to be obtained;
  • nichrome wire, which the knife will melt the filler;
  • A plate that will work as a limiter, setting the thickness on which cutting will be carried out.

As a power source, it is easy to use a powerful battery charger, which allows you to adjust the voltage on the thread. Naturally, to make a thermal with your own hands, you will need a comfortable handle that will hold the side plates of the cutting part.

We collect a thermal

It’s very simple to assemble the design with your own hands. The voltage from the power supply can be supplied to the nichrome wire by swinging it to the contacts, where the voltage supply wires are suitable. And with a small thickness of the steel plates, you can supply power on them, while the wire can simply be screwed in the lower part, you will need to drill only two holes.

The initial stiffness of the structure sets the pen block. Each side plate is attached to the corners with two bolts located vertically. Increases the rigidity of the restrictive bar.

For example, it can be simple bolts and P-shaped brackets worn on the side parts.

Despite the simplicity of the design, the thermal knife for processing the filler of the SIP panels works very effectively, even with your own hands. Due to the small thickness of the side plates, you can get rid of the need to form a side cut, especially since you can sharpen the edge of these parts if they are made of steel.

It is important to know: are the SIP panels harmful to health?

The nichrome thread using a voltage regulator has the desired temperature (selected experimentally) to quickly sample the groove. As a result, such a cutter will be able to guarantee quick work and cleanliness at the construction site. In addition, such a thermal will cost literally a few dozen and can be assembled using existing equipment.

DIY cutting cutter for foam

Homemade foam cutting devices

  • Power supply unit for homemade thermal cutters
  • Homemade cut for working with flat sheets of foam
  • Homemade thermal cutter for curly cutting
  • Homemade thermal cutter from a soldering iron

Foam. light, technological and durable material, which also has a low thermal conductivity, is a find for the builder or home master.

It can be used not only as a heater, but also as a structural material for the formation of a variety of models, blanks, shapes, etc.D.

But foam is produced in the form of rather large blocks, with which the material is cut with a knife or saw due to the destruction of its structure.

Figure 1. Scheme of an adjustable power source.

Electric cut for foam, the working element of which is usually a nichrome wire, heated to a temperature of several hundred degrees, cuts the foam neatly, smoothly and without crumbs. This happens because when in contact with the wire heated with wire, the foam instantly melts, forming a durable sprinkled cut.

Making a Hot Wire Foam Cutter | DIY Foam Cutting Machine

In this article, you can get acquainted with the designs of homemade cutters for foam for various purposes.

Power supply unit for homemade thermal cutters

Figure 2. Scheme of the cutter that allows you to cut flat sheets from the foam block.

The power dissipated on the nichrome wire at this heating temperature depends on its length and cross.sectional area. It is better if the wire is quite thin (0.1-0.2 mm).

Its resistance in the cold state of the order of several ohms. The operating temperature corresponds to the start of redness of the wire.

With a wire length of 50 cm, about 50 watts of power at a current of about 5 A are dispersed on it.

If the cutter for foam is used only episodically, you can use battery battery as source of current. Sometimes it is even more convenient, and in terms of security is better than using a network power source. Nights can be adjusted by changing the number of batteries included in series.

But with systematic work with cutters, a universal network power source is preferable. Such source is easy to make with your own hands. Its base is a lowering transformer designed for a power of at least 100 W, having a secondary winding designed for voltage 15 V. The diameter of the wire, which it is wound, should be at least 1.5 mm.

For a smooth change in current strength, of course, you can apply a suitable rheostat or make a secondary winding with the executions and put the switch.

But the most convenient option is the use of a vehicle with a smooth adjustment of the output voltage (Latra), to the output of which a lowering transformer is connected.

The diagram of such an adjustable power source is shown in the rice. one. Here T1 is a LATR, and T2 is a lowering transformer.

DIY foam cutting device

Foam can be cut not only with the help of a nichrome thread, but also a metal plate. The basis should be taken by a regular soldering iron with a power of 60 watts. It will need to be reconstructed. instead of sting to place a plate of a knife. The main material is also used by thermal.melting synthetics.

A wooden leg should be additionally equipped with supporting legs. Previously in the board you should make a gap and place a knife in it. Additionally, the device should be equipped with a stand with brackets

The safety screen plays the considerable value, which will further protect a person from burns

In the process of cutting, thermal must be placed at an angle to the surface. The blade is also dragged from two sides at once. Previously, you should shake your skills on unnecessary trimming of the material. In this case, a flat and beautiful surface will be guaranteed to be guaranteed.

How to choose a cutting wire

A suitable cutter can be made of nichrome wire (x20N80), which is used in the design of most household appliances as a heating element. In terms of mechanical characteristics, it is comparable to the usual steel, while it has a large specific resistance and the heating limit to temperatures 1200 ºC. For the manufacture of devices for cutting, a wire with a diameter of up to 10 mm is available.

The exact and smooth thread 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 energy consumption and the absorption of heat itself in proportion to its density. Therefore, for effective and safe cutting, you need to choose a wire of suitable thickness in order to eliminate the melting of the metal with maximum heating.

How to make powerful cutter with Nichrome Wire

Calculation and preparation of the electric part

For the safe operation of the device, you need to correctly mount the conductive elements that are connected to the source of electricity through the fragmentation terminals. To cut the material, you can use alternating or direct current. The power of the source is calculated on the basis of the fact that for effective cutting for 10 mm wire will need up to 2.5 watts (for 500 mm. 125 V).

The current voltage is proportional to the resistance and is calculated by 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 Ohms, a current source with a voltage of 12 V with a load current of 12 A. Changing the length to a larger or smaller side will require a similar increase or decrease in voltage at the same current strength.

Electricity sources and connection diagram

Safe cut provides a connection to a conventional household network 220 V through a car transformer. To adjust the voltage in the only primary winding, a handle is provided, with which the graphite wheel is moved and the voltage is removed from the corresponding area. This parameter can be changed in the range from 0 to 240 V. Connection to the current source is carried out through the terminal box.

When connecting a home.made machine for cutting foam to the mains, you need to make sure that the phase does not have to be on the general wire. All the necessary parameters and the connection diagram can be found on the transformer case. Before connecting to the network, you need to check the performance of the device using a multimeter.

A simpler option for supplying current to the wire consists in using conventional lowering transformers with removal from secondary windings. In this case, you do not have to select the voltage value, since this value is always constantly and enough to heat the wire to the desired temperature. You can choose the desired value with the initial setting of the transformer, providing in the chain a certain number of turns of windings.

You can heat the wire for cutting foam and using household appliances. At the same time, the following nuances take into account:

To make a thermal for foam or foam, it will not require significant expenditure of effort and time. 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. Of great importance is reliable insulation of contacts and control of the phase position, which cannot be connected to the wire.

Typical construction remained in the distant past. Today, every owner seeks to make his home functional and individual

At the same time, attention is drawn not only to the design

No small importance is of noise insulation, heat conservation and proper ventilation. With the help of foam, you can perform a large number of work

However, manufacturers package the material in large sheets. That is why it is important to choose a reliable and comfortable tool for cutting them

With the help of foam, you can perform a large number of work. However, manufacturers package the material in large sheets

That is why it is important to choose a reliable and comfortable tool for cutting them

Non.traditional cutting method. nichrome thread

All the methods presented above allow us to process polystyrene foam exclusively in a direct flat line. In those situations when you need to make an unusual figure, a semicircle or zigzag, you can use non.traditional methods. For example, a nichrome thread. With its help, you will learn how to cut polystyrene, so as not to crumble, with minimal temporary and physical costs.

First you will need to perform some preparatory work to assemble the necessary equipment. So, you should take care of the presence of a small spring, a transformer for 24 volts and nichrome wire. The working surface of the table is set at an angle from 20 to 60 degrees. We pull the wire across the table. We fix the ends of the wire on each side of the table with a spring.

No garbage, everything happens very quickly and without unnecessary gestures. The only difficulty is the assembly of the necessary equipment, since not everyone has transformers.

Thus, there is nothing superfilled in what and how to cut the foam at home. Even with the help of a regular knife, you can perform all the necessary operations. If you purchase better equipment, then the processing process will take a minimum of time, without additional effort, noise and garbage.

Homemade cut for foam

Homemade cutter is designed for minor work. It is not possible to reveal the entire sheet of polystyrene foam. To cut foam at home, you need:

  • In a wooden bar 10-11 cm long, make 2 holes. They must coincide with the diameter of the pencils. From the edge you need to retreat 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 a foam sheet of almost any thickness.
  • Paste both pencils into the holes with the help of thermoclay or PVA.
  • In each of the pencils on top, make a small hole for copper wire.
  • Bend the copper wire with round.liners so that at its ends there are small rings. After that, install in the holes in the pencils.
  • Glue the battery connector perpendicular to the wooden bar. Additionally, he will play the role of a pen.
  • Stick the switch to the bar so that you can de.energize the string.
  • Then connect 2 wires to the connector. After that, connect with the switch, and then put each to a separate pencil. So that the wire does not sag and does not interfere with the work, it is fixed with electrical tape. To ensure reliable quality of connection, you need to solder the wires to the connector. The joints must be isolated using a heat.shrink tube or island.
  • Clean the second end of each wire from the braid and fasten it to a copper wire. Solder the connection.
  • Put the nichrome thread into rings made of copper wire and fix it on them. The string should be tightly stretched between the pencils. When heated, it stretches and sags slightly. The stronger the tension, the less sagging.
  • Insert batteries into the connector and start cutting foam sheets.
foam, nichrome, wire, your

Thus, you can make a simple device for cutting foam with your own hands. And another option for making a machine, look at

Cutting material using hot tools

For cutting a sheet of foam, you can use the most ordinary knife, if you first prepare it for this procedure:

  • It is necessary to make sure that the length of the knife with a margin is more than the thickness of the sheet, which will have to cut.
  • Next, you need to mark the lines on the sheet along which it will have to be cut off.
  • The next step will be heating a knife using a gas stove or a special gas burner. A hot knife must be carefully drawn along the intended line, the foam will begin to melt and cut clearly along the line.

It is important to consider that it will not work to achieve a perfectly even cut with this method, and it is also suitable only for cutting small pieces of material. The fact is that even slightly shaking hands will not be allowed to achieve a flat line, and a constantly cooling knife will not allow to make a neat and long section.

But if your goal is to cut off a small piece, then the knife will allow you to do this very quickly and without unnecessary expenses of funds and time. Please note that the knife after cutting should in no case be used in the kitchen or in everyday life, since the foam contains toxic substances.


Simple cut from a soldering iron

If you need to make a lot of foam blanks, but you don’t want to make too complicated, then you can use its simple analogue that works on the basis of a conventional soldering iron.

It is important to choose a not too powerful soldering iron, since its temperature is excessive for conventional cutting of the sheet. If the power is too large, then the foam will smoke strongly, smoke, cut it badly.

The next step will be the selection and installation of the nozzle on the tip of the soldering iron, since the standard tip is not intended for these purposes. We need to find or independently make a long and flat tip, which will look like a small knife blade, but less acute. It is good for making such an item that a copper wire is suitable, folded several times. Another option is just to get the shaft tip and give it the desired look.

Further, the tip is tightly fixed on the tip of the soldering iron and you can proceed to cutting.

The soldering iron is inserted into the outlet, heats up and cuts the foam according to a similar principle with a knife. The main plus of this method is no need to constantly heat the knife, cutting can go continuously.

A cutter from a soldering iron

Special cutting for cutting foam

If you want to regularly make foam products on a regular basis, so that they turn out really even and good, you will have to make a special cutting machine that will allow you to do all this.

for a special cut for foam

On the Internet you can find many options for this design that differ in size, appearance, but they have one essence. We will analyze one of the most popular and simple designs that has established itself well.

foam, nichrome, wire, your

Table 1. The main methods of cutting foam:

foam, nichrome, wire, your

Methods of harsh of the prime ministry

A special knife

In the construction store you can find a device that is specially created for cutting this material. The knife should be sharp. For thin samples of the material, it is allowed to use a medium stiff blade. The tool will quickly and effectively cut the foam with a thickness of up to 8 sentiments. If the quality of the final material is important, it is recommended to pre.train on waste.

When using a knife, the material can be very crumbling. In this case, an ordinary string comes to the shift. To obtain the fastest cutting, it must be pre.heated to the desired temperature. At home, the device can be assembled independently. To lower the temperature should additionally include a lowering transformer in the network. The device has the same principle of action as with a nichrome thread. It is important to select such a pipe so that its thickness does not exceed 20 mm. Thanks to the device, it is possible to quickly cut the foam up to two centimeters. The quality of the string is of considerable importance. it should be thin and acute.

DIY foam cutting device

Foam can be cut not only with the help of a nichrome thread, but also a metal plate. The basis should be taken by a regular soldering iron with a power of 60 watts. It will need to be reconstructed. instead of sting to place a plate of a knife. The main material is also used by thermal.melting synthetics.

A wooden leg should be additionally equipped with supporting legs. Previously in the board you should make a gap and place a knife in it. Additionally, the device should be equipped with a stand with brackets. The safety screen plays the considerable value, which will further protect a person from burns.

In the process of cutting, thermal must be placed at an angle to the surface. The blade is also dragged from two sides at once. Previously, you should shake your skills on unnecessary trimming of the material. In this case, a flat and beautiful surface will be guaranteed to be guaranteed.

The main methods of cutting foam

The best option for thermal insulation of the structure is foam. Typically, for these purposes, not a dense structure is chosen, due to the low cost. This causes inconvenience during cutting, the structure of the cells is poured, and with a slight effort you can break the structure with your hands. The tool for cutting foam has various modifications, finished options are sold, you can also make a design with your own hands.

It is important to understand that the structure of foam is categorically refers to the effects of some liquids. Acetone or gasoline destroys the structure of the foam, the product will have to be reinforced. The temperature operating modes are no more than 50 °.

Foam cutting at home is performed by many improvised tools. For example, when working with small blanks, the simplest way is to use a stationery knife. The process is inaccurate, The blade is quickly stupid, for better processing, the knife can be heated.

Each of the devices has advantages and disadvantages, it is important to note the characteristics of the foam, choose a tool for cutting polystyrene in size before a sharp one with your own hands.

Manual machine for figure cutting of foam

  • In household stores you can purchase a special tool. a knife with a heated blade. The work of this device is carried out from itself, in order to avoid slipping and injuries. The main disadvantages of the cutting knife that they can cut the material of a certain thickness, for even work you need to correctly mark the product, spend on this time.
  • A variety of a heating knife can be a soldering iron with a special nozzle. It has a higher heating temperature, when working, it is necessary to be careful, the molten drop when it hits the skin does not cause joyful sensations.
  • A shoe knife for cutting foam is used with a long blade up to 40 cm. The tip of the knife remains stupid, and the wide blade should be perfectly sharpened. Correction and sharpening are carried out every 2 meters of cut off products. The process will be accompanied by a screech, you can exclude unpleasant sounds with the use of headphones.
  • Thicker products can be cut with a hacksaw on wood with small cloves. The smaller the level of teeth, the better the quality of the output part, however, naps and bevels will still be present. The method does not require the application of special products, is often used for long rectilinear foam sections.
  • The most popular way is to cut foam string. The performance of this method is equal to industrial equipment, it is enough to build a small design. The string is used when working with foam of various grain and density.

Some cases, for lack of any of the above cutting tools requires electrical engineering intervention. Corner grinder is used with a minimum thick disk. Work implies the presence of increased noise, garbage from foam particles throughout the territory.

The processes of insulation of one dwelling can be performed by a manual type tool. The wire for exposure to foam is used on a special stand, pre.prepared. The design consists of a nichrome wire, easily made with your own hands. The connection scheme consists of two mounts, cargo for tension and power to the network. In cases where production volumes are increased, special machines for foam processing are used.

You can purchase them in specialized stores, as well as make them yourself.

Classification of machines

The design features of the units do not differ from each other. In each of them, cutting occurs due to a heated wire fixed in a certain position. Some of the modifications have up to six adjustable strings, this allows you to produce more massive work. Foam cutting machines can be with a rotary table, stationarly fixed cutting element.

Devices are divided into several categories:

  • equipment with software controls that allow you to cut out figures of increased complexity;
  • portable cutting elements;
  • transverse or horizontal types of cutting.

The most complex design machines allow you to work at once on a few planes of the product. The productivity of devices for cutting foam is designed for industrial purposes, for one approach some models can process over 10 meters.

Tools and materials

This project was made of things that were lying at my house. If you need to purchase all the components, it will probably cost about 20-30 (excluding the power supply). I used a table variable power supply because it allows you to change the temperature of the wire.


  • Birch plywood (12 mm and a piece of 18 mm);
  • Glue for wood;
  • Screws (approximately 22×4 mm);
  • 2 rym-bolt M6 or 1/4 inches;
  • 2 bolts with a square heading M6x40 mm or 1/4 inches;
  • Nuts and washers M6 or 1/4 inches;
  • 2 handles M6 or 1/4 inches;
  • Nichrome wire (I used 0.5 mm, 30 cm);
  • Pushing spring;
  • Bronze sleeve (additional inner diameter 6 mm) or 1/4 inches;
  • Banana plugs (optionally, socket);
  • The puck is large M12;
  • Wire;
  • 2-wire connector (round);
  • Rubber legs (optionally);
  • Trim with wood (optional);
  • Power power supply (or other power source with proper voltage/current).


  • CNC milling machine;
  • Laser engraver (option);
  • Clamps; ;
  • Grinding machine/sandpaper;
  • Screwdriver;
  • Ticks for compressing wire connectors (option).


Using a CNC milling machine: this project was designed for cutting on a CNC milling machine. I used Cambam to convert all DXF files on the way to the machine tools. Cambam. This is a very simple program that works very well with simple 2D elements. I have attached all DXF files below.

Feed and speed:- 1200 rpm;- 1500 mm/min;- depth 3 mm per passage.

The end cutter with the descending spiral of this project I used a special carbide end cutter with a spiral descending edge. This end cutter does not pull the chips up, but pushes it down. This type of end milling cuts works very well with plywood. I found that ordinary end mills can leave very rough edges, because they pull up the upper layer of veneer. The end cutter with the lower edge leaves a very clean edge! The main advantage for me is that I do not need to use ledges to keep the details on the spot. Since sawdust fall between the workpiece and trim, the pieces are held in place reliably enough to cut them through. For plywood, I always use carbide end mills. The glue in the faner really very quickly dulls the end mills of high.speed steel.

Manually: if you do not have a CNC milling machine, you can still make this project. You can print DXF files as templates and stick them on the plywood. Ribbon saw, jigsaw or even a jigsaw machine should fit well to cut out all parts. Please note that all bends and holes on the handle are purely aesthetic. If you want, you can leave all the squares. The s in the table and at the base serve to additional support and leveling of parts, but are not completely necessary.

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