Nichrome foam cutter. Styrofoam cutting - high-quality cutting of material at home

The issue of home insulation is very relevant today. Sheathing the facades of houses with foam plastic is one of the most popular types of insulation. And this is very reasonable, because. the process of such insulation is simple and understandable, and all necessary materials always available for sale.

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

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

Partially, this drawback can be leveled by laying the foam on a thicker layer of glue. But the maximum allowable thickness of the adhesive layer often cannot cover the magnitude of the differences in the plane of the walls. In addition, too large differences lead to unjustified overspending of glue.

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

In order to quickly and evenly cut the foam of 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 the device of the machine for cutting foam

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

For the manufacture of the machine, the following components are needed:

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

A nichrome thread (spiral) is used as a cutting object. You can either buy it in a store or extract it from old ones. household appliances, in which they were used as filaments (hair dryer, for example). The thickness of the spiral 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 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 that uses wires that give 12 watts (yellow and black) to connect to the spiral.

To operate such a machine, it is enough to have an output voltage of 6-12 watts.

It is necessary to correctly adjust the length and thickness of the filament and to match the voltage. If the thread is too hot, it may break. Well, if the thread is slightly heated, then cutting will be slow.

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

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 foam into bars, a short spiral length is needed.

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

Two spirals cut the sheet into three parts in one pass. The stand is stuffed with guides for smooth feeding of the foam.

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

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

Step 1. Preparation of the countertop. As a tabletop for a do-it-yourself foam cutting machine, you can take any piece of chipboard of the right size. The surface on which the foam will move must be smooth. Holes for racks are drilled in the table top. It is convenient to use metal pins with a thread with a diameter of 10-12 mm as racks. The height of the racks should correspond to the thickness of the foam sheets plus a margin in height. The pin is fixed with nuts.

To give the structure stability, bars are attached to the tabletop from below, which will also serve for the safe passage of an electric wire.

Step 2. Connecting the current supply wires. From below, under the tabletop, the wires are connected to metal rod-racks: the wire is wound around 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 will be through a plug, which will be connected to the LATER socket. It is possible to connect via self-clamping terminals, as well as by twisting and soldering. It depends on the selected power supply.

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. Fixing the Nichrome Spiral. Nichrome spiral is fixed between two racks. 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. The thread in this state will not give a quality cut. Therefore, the thread is fixed in an initially stressed state, so that the spring is slightly stretched.

To fasten 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 made 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 in drilled hole thread a nichrome helix. Next, it is pulled so that the spring is stretched, and fixed.

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

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

The cutting speed depends on the temperature of the filament, which in turn depends on the voltage applied and the thickness of the filament itself. Do not try to apply more voltage to achieve high speed, because. this can cause the filament to burn out quickly. Here, a balance between tension, thickness and length of the thread must be selected empirically. The thread should not overheat during operation. When heated, it becomes 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, smooth adjustment is easily done if LATER is available. But if it doesn't exist, then laboratory block power supply can also be made from a computer power supply, the video below has more information. 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 activities must comply with safety regulations for working with electrical appliances. The power supply must be grounded, 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 connected to the mains only while working with foam. After work, it must be immediately turned off. While working with the machine, touching the metal parts and the nichrome thread itself should be avoided.

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

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

Useful video

Cutting foam does not seem to be a difficult task, but to do it carefully, you need to have the skill and know some secrets. How and with what to cut foam at home and how to make a machine yourself to simplify this work? Now I'll tell you!

Styrofoam cutting

The scope of polystyrene foam is very wide. Parts for aircraft modeling are made from this material, it is used in the manufacture of toys and furniture, volumetric letters or sculptural elements for advertising, etc. We are interested in a very specific area - construction.

Types of cutting

In construction, foam plastic is used as a heater for roofs, walls, floors, ceilings, foundations and other structures. In the vast majority of cases, thermal insulation consists of expanded polystyrene sheets, which are sold in stores and have standard sizes.

During the installation of sheets, they constantly need to be cut, and here the following cutting options are possible:

1. Longitudinal. This refers to the case when you need to cut a sheet of foam along its plane, for example, into two parts. For example, to make two sheets 25 mm thick from one sheet 50 mm thick: neither a knife nor a hacksaw will help here;
2. transverse. When it is necessary to cut a piece from a sheet desired shape, that is, you will cut perpendicular to the plane of the sheet itself. In this case, you can use a knife, saw and other similar tools;

1. through. Often it is necessary to make holes in the thermal insulation layer for the entry of an electrical cable, pipe or other communications. With some skill, you can get by with a knife, but there are more effective tools that I will talk about;

1. curly. It is used when the edge of the sheet needs to be cut according to a clearly defined pattern with curved lines and a complex profile. Here, a regular knife will not work, and you will need a special tool.

Cutting tool

Styrofoam cutting can be done with a variety of tools. Most popular:

• construction knife. During insulation work, a knife is most often used to cut sheets. It can be a construction, stationery or shoe knife. The main thing is that it is well sharpened. The knife is carefully drawn along the cut line, strong pressure no need. If the sheet is not cut through, it is broken along the slot;

• Hacksaw. For cutting thick sheets, it is convenient to use a hacksaw for metal or wood with a fine tooth. Sold special saws for foam;

• Nichrome wire. A piece of thin nichrome wire is heated by passing an electric current through it. Fixed in a certain way and stretched, a hot string cuts the foam like butter;

• Thermoknife. In fact, this is a soldering iron, the tip of which is made in the form of a knife blade. The blade heats up and perfectly cuts any plastic, including foam;

• Laser ray. Styrofoam can be cut with a laser. This technology is used in the production of sculptural elements or in large-scale production for cutting a wide variety of shapes.

In construction, cutting of even rectilinear shapes is most often required, which the knife can handle quite well. A thermo-knife is ideal in this case.

If you need longitudinal cutting in thickness, a nichrome string is best suited.

How to make a nichrome wire cutter

How to cut styrofoam in thickness? This question often arises before the builder when it is necessary to dissolve the insulation sheet and make it thinner. For these purposes, a nichrome wire cutter is suitable.

The idea of ​​​​the machine is quite simple: a string is pulled over a tabletop made of board or plywood, through which a current is passed. The string is set horizontally at the required height, heated by the current and cuts the sheet, which the cutter moves along the tabletop.

Making such a machine with your own hands is quite simple:

Image	Description
	Making a countertop. Choosing a board for the countertop. It can be thick plywood or MDF, a solid board, for example, a cabinet door or a table top.
	We fasten the studs. We fasten threaded steel studs in the corners of our tabletop. To do this, we drill holes and insert anchors into them, which we fix with nuts.
	Heels on the reverse side. On the reverse side of the tabletop we fill the heels from the boards. They are needed so that the ends of the studs do not rest on the floor, and the structure is level. In addition, it will be possible to run wires under the tabletop.
	First wire. Connect the first wire to the stud. It is better to wrap it around the anchor under the washer, solder and tighten it with a nut.
	Second wire. Similarly, we connect and tighten the second wire with a nut.
	Holes in washers. We take two washers that are freely put on the studs. We drill holes, as shown in the photo.
	Washer sharpening. Opposite the holes along the inner edge of the hole in the washer, we sharpen. This is necessary so that the washer fits exactly into the grooves from the thread and cannot move along the stud.
	Spring. We put the washers on the studs and set the holes inside. We pass the end of the spring into one of them. Any tensile steel spring, such as a clamshell spring, will do.
	Attaching the wire to the spring. We tie a nichrome wire to the free end of the spring and measure the distance to the opposite pin. We leave a margin of 30-40 cm and cut off the excess.
	string tension. We insert a screwdriver into the end of the spring and stretch it. With the second hand, we pass the wire through the hole in the washer and tie it into an interference fit.
	We select a power source. It is best to use a step-down transformer, which gives an output of 6-12 V at a current strength of 6-10 A. Charging for car batteries, a power supply for a computer, a transformer from an old TV are suitable.
	We set the stretched thread in height. To do this, you can use a square, ruler or tape measure.
	We turn on the machine in the network. We connect the supply wires coming from the studs to the outputs of the transformer. We apply voltage to our cutter and wait 10 seconds for the thread to warm up.
	cutting. We take a sheet of foam and lead it along the countertop. The wire will cut off pieces of the thickness we need, which we set earlier, from the sheet. Cutting styrofoam with hot wire produces poisonous smoke. Use a respirator and work in a well-ventilated area.

Conclusion

I think now you understand how and how foam is cut. There is different ways and tools, choose the appropriate one for a particular case. To better understand the topic, watch the video in this article and ask questions in the comments if you have any.

Styrofoam- one of the most popular nowadays building materials. It is widely used for soundproofing and insulation of rooms.

The main properties of polystyrene that make it popular are:

• low thermal conductivity;
• cheapness;
• Fire safety;
• ease of operation.

Styrofoam is produced at factories in large sheets, which can differ significantly in their dimensions. Also, this material can have different density, color scheme, fraction size.

The main operation that is done on the foam is cutting. It allows you to get from large sheets this material elements of the required size.

Cutting methods

Styrofoam can really be cut even with a regular blade

For ordinary people who are going to make repairs on their own, a logical question arises: how to cut the foam correctly?

All cutting methods can be divided into two large groups:

1. Mechanical
2. Thermal

At home, the easiest way to do mechanical cutting, which is carried out with simple tools.

The second method, thermal, is the use of special machines and equipment.

Tools

Hot electric knife for cutting foam and foam (150W, 220V, blade 150mm)

The most commonly used foam cutting tools are:

• knives;
• hacksaws;
• soldering irons;
• machines with nichrome wire as a working part.

In order to cut factory foam sheets into separate pieces of the required size at home, they most often use a handy tool for cutting foam. These are primarily stationery, shoe knives, hacksaws for wood and metal with fine teeth. It is necessary to cut the foam carefully, as it can crumble a lot during this operation. Moreover, the larger the grain, the stronger the crumbling will occur.

Knives for cutting foam are well sharpened - the sharper the blade, the faster and more accurately the cutting will be done. In addition to stationery and shoe knives, special foam knives with a special rubber lining are used. Also, in addition to sharpening, the blades are heated to facilitate cutting.

These tools can only make straight cuts. With their help, you can only get elements with straight sides: squares, rectangles, trapezoids, etc.

The main disadvantage of cutting with knives is that the thickness of the sheet should not exceed 5-7 cm. Hacksaws and saws with fine teeth are used even with a starting material thickness of up to 30 cm, but the cuts are rough.

Note

Mechanical cutting is always accompanied high level noise, as well as the occurrence a large number garbage.

With the help of figured cutting of foam, you can make sculptures, figures and decorative elements.

Figured cutting of polystyrene is carried out exclusively by a thermal method. To do this, use soldering irons with special nozzles, as well as machines.

Drawing machine for cutting foam

Figured cutting of foam plastic can also be done on home-made equipment. Handicraft machines are made from improvised means: old furniture, wooden blocks, plywood, chipboard. Use the materials that are directly available. An obligatory element that cannot be replaced is a thread or wire made of a special alloy consisting of nickel and chromium.

The main advantage of cutting with a special machine with nichrome wire is the possibility of cutting, both longitudinal and transverse.

In the first case, a vertical string setting is used. For transverse cutting, a horizontal arrangement of a nichrome thread is used.

Cross cutting allows you to get sheets of a strictly specified height. This is very useful when a piece of styrofoam is thicker than necessary. Cross cutting cannot be done with knives or hacksaws; for this, it is imperative to have a machine with nichrome thread.

A lot of videos have been shot on how to properly cut foam on such a machine, which are worth watching before starting work.

Machine manufacturing

In order to make a homemade machine, from the materials you will need:

• base for the machine;
• wooden beam;
• self-tapping screws;
• spring;
• nichrome wire.

Of the tools useful:

• screwdriver;
• drill;
• pliers.

You can also use a laboratory adjustable autotransformer (LATR). It will allow you to get the necessary voltage, which will make it easy to cut the foam, but it will not melt it.

Any flat sheet with smooth surface so that the foam can be easily moved along it. Suitable plywood, pressed wood, corrugated board. It is not recommended to use plastic - under the influence of temperature, it can also begin to deform.

Two self-tapping screws are screwed into the base so that you can easily change their height. A nichrome wire with a diameter of 0.6 - 0.8 mm is attached to the screws. At the same time, on the one hand, this is done with the help of a spring, which will negate the thermal deformation of the wire, which will prevent sagging and weakening of the cutting element.

Wires are attached to the screws, through which current will be supplied. Its voltage should not exceed 5-12 volts. Otherwise, the foam will melt very strongly and it will become impossible to obtain even sides - notches and crevices will form on them.

On the question of how to cut the foam, everyone must answer for himself, based on the size of the original sheet, what is its density, what is the size of the individual grain, and also what shape the elements should be in the end.

Wooden decor elements are present in the homes of each of us. Sometimes we go to the store to buy a beautiful wooden frame or jewelry box for our home or as a gift to our loved ones, friends and relatives. However, the best gift is a gift made with my own hands, and to make a beautiful frame or box, we need a cutter or a nichrome electric jigsaw, which we will do right now.

Watch in the video how a nichrome cutter is made:

So, to make a cutter, we need a 12 volt 5-10A power supply (you can use a computer unit), nichrome wire with a cross section of 0.4-0.8 mm (you can disassemble a wire resistor or the same boiler that uses nichrome thread), two pieces of a cut branch , from which we will make handles, copper wire 1-1.5 m long, as well as two nails or two pieces of hard wire.

The first thing you need to take care of the handles. To do this, you need to drive a nail into pieces of a branch or stick a wire. For convenience, it is better to use a branch from a soft tree. When the wire or nail is inserted, you should take round-nose pliers and make rings from the protruding parts of the wire so that the wire itself, as well as the wires, do not slip off during twisting.

The next step is to take any yellow and black wires from the power supply and connect them to copper wire, which will be the main one in our cutter, not forgetting the need to insulate the wires.

When you plug the power supply into an outlet, it will not start immediately. If you are using older models of computer units, you can separately install the switch by connecting green wire with any of the blacks. With new models, everything is much easier: it is enough to short-circuit the same two wires for a fraction of a second using an ordinary paper clip.

It's time for the most important part: choosing the right length of nichrome thread. In order to do this, you can use a special formula, but there is an easier method, which is known as the poke method. The desired length of the thread can be determined by winding it on wooden block, connect the positive wire to one end and gradually bring the negative wire closer from the other end until the thread starts to turn red.

Attention!!! If the length of the nichrome filament is incorrect, the power supply may overload and fail, and the filament may also quickly break.

After calculating the length of the thread, it remains only to cut off its excess part and wind it around two rings of two handles. On other rings, you should wind the wire from the power supply.

The process of production and installation of foam is not complete without trimming it. Without giving the blocks the required shape, the process of transportation and implementation becomes more complicated. In each individual case, panels of a certain size are required for mounting on a building or any device. What can be used for high-quality cutting of foam? This will be discussed in the article.

Why difficulties arise

Styrofoam is a material that consists of granules compressed under certain conditions. Although the granules are sintered together, they do not fuse, which contributes to the ease of separation of the granules. This structure creates difficulties in the process of cutting the material. If someone had to deal with cutting foam, then it is easy to see that sheets of increased density are cut easier and for this you can use a well-sharpened tool with a thin sting. Cutting can be done with power tools. At the same time, the higher the speed of the blade and the smaller the tooth, the faster and easier the cut is.

In industrial conditions, foam cutting is carried out by other methods, one of which is hydroforming. A thin jet of water is applied to the block under high pressure, which makes it easy to cut and leaves virtually no waste. Another method is the use of nichrome thread. It has a high resistance, so when electricity is passed through it, the temperature rises to a certain value, which causes the foam to melt. On industrial machines, several threads are installed at once, which perform a cut in several planes.

cutting technology

The cutting technology and all the tools that are used for this purpose can be divided into two large groups:

• mechanical tool;
• electric.

Each of the methods should be considered separately.

mechanical method

The mechanical method of cutting foam involves the use of such tools:

• knife
• jigsaw;
• saws.

The first cutting method involves a sharp knife. Most often, a shoe knife made of Rapid is used for these purposes. Its advantage is a strong handle and a special sharpening angle. But this option is only suitable for those cases when it is necessary to perform work on cutting foam with a thickness of up to 4 cm. If we are talking about sheets with a greater thickness, then a blade of greater thickness will be required, because too thin can bend, which will lead the cut line. In addition, during the cutting process, you will need to periodically bring the blade down, so you need to keep a stone of the required grain size on hand. After marking the foam sheet, it is necessary to lead the knife along the cut line towards you, holding it at an angle. In some cases, it will take several passes to achieve the desired result. The eyeliner of the blade is required every two meters of cut.

Another tool that is great for cutting foam but with a lot of waste is a hacksaw. In this case, it is necessary to choose a product with a small tooth. A metal sheet will not allow you to cope with the task effectively, so a hacksaw is used for wood. Due to the greater length of the hacksaw blade, thicker sheets can be cut. Wherein best solution there will be a hardened tooth without a large set, which will make the cut line thinner. The advantage of using such a tool when cutting foam is greater safety, since the sharp part of the blade is not directed towards the body.

The power tool is also suitable for cutting foam. Excellent tools in this regard are a reciprocating saw and a jigsaw. The difference between them lies in the speed and depth of cut. The effect is in many ways comparable to that achieved when working with a hacksaw. For work, it is better to purchase nozzles with a minimum tooth of the canvas on wood. Thanks to the use of a jigsaw, there is more freedom if it is necessary to perform a figured cut. This is easily done, because the width of the canvas is small. The cut is more accurate by adjusting the speed of the blade. It is recommended in the process to turn off the pendulum stroke that is applied to the wood in order to reduce the amount of waste.

Note! If there is no other tool at hand, then you can use a grinder with a diamond blade to cut the foam. In this case, the rotation speed must be selected in such a way that it does not melt.

Nichrome thread

The most comfortable cutting of foam is performed with a hot nichrome thread. At correct selection speed, it is possible to achieve a minimum seam and not melt the ends. The essence of cutting is that the sheet is drawn through the wire along the designated line. You can make such a cutting device yourself. This will require:

• LATR or transformer;
• nichrome thread;
• insulators;
• holders.

The thickness of the tungsten filament that will be used to cut the foam is 0.2mm. It can be purchased at a specialized store or removed from household appliances. The first step is to install two racks, between which the thread will be stretched. It can be done by anyone convenient way which makes cutting easy. Insulators are fixed to the racks, which will prevent them from heating. Springs are mounted to the insulators to ensure a constant thread tension. You can connect wires to them, which will come from LATR or from a step-down transformer.

The rheostat is a better source than a conventional transformer, since the power consumption, and, accordingly, the heating temperature of the thread, can be easily adjusted depending on the thickness of the foam. A car battery can be used as a power device if foam cutting is rarely performed. In this case, the cutter acquires a certain autonomy and additional security. It is important for the design to choose the right length of the wire so that it is heated to the required temperature. The assembly process of such a cutting machine is described in detail in the video.

Advice! An interesting cutting device can be made from a soldering iron with a power of 100 watts. To do this, it is necessary to dismantle the factory sting and install in its place a thin metal plate or blade, which, when heated, will give an effect similar to a machine tool.

Precautionary measures

In the process of cutting foam, certain precautions must be taken to achieve best result and keep the master healthy. One rule concerns the use of a cobbler's knife when cutting styrofoam. Since the movement of the blade occurs in the direction of the human body, it is necessary to stay out of the plane of the passage of the knife. In the process of cutting foam, the blade may stop, and more force must be applied. If it is not controlled, then you can cause serious injury to yourself when the blade slips. The knife should have a comfortable handle that is easy to hold in the palm of your hand. This improves cutting accuracy.

Using hand saw and similar tools for cutting foam, you must be careful not to get your fingers in the movement of the blade. To do this, you can use a restrictive bar, which is located next to the cut line. Before starting work, it is also necessary to check the reliability of fixing the working canvas, as well as the insulation of the power wire. A safer method when cutting foam is to use a cordless tool. When assembling an electric cutter with a nichrome thread, it is better to use a voltage reduced to 12 or 24 volts. If a hand gets on the thread, a burn will occur, if this happens when powered by 220 volts, then an additional electric shock will be received.

Summary

As you can see, there are many ways to cut foam, for which almost all available tools are used. Curly trimming allows you to create three-dimensional letters to form names, in addition, when insulating some surfaces, a curly cut is required. Thanks to the nichrome thread, it is possible to cut the foam in such a way as to form a box for pipe insulation. For better joining of foam sheets, a quarter can be sampled at the ends, which will avoid cold bridges.