DIY foam cutter

Polystyrene foam is an inexpensive material from which craftsmen make a wide variety of products. It is very popular not only because of its low cost, but also because of its ease of processing. Not everyone knows that foam plastic does not have to be cut with a regular knife. In this case, it will crumble very much and it will be simply impossible to make an even cut.

But this material melts very well, and at a relatively low temperature. That is why the most convenient way to work with polystyrene foam is to cut it using special cutters that rely on high temperature. But cutting foam plastic with your own hands is also possible in other ways, which we will definitely consider.

Step-by-step production of a thermal cutter from improvised materials

Processing Foam When making power tools for cutting foam, you can use a variety of elements and devices.
For example, a thermal knife can be made from a soldering iron, a burner and/or an old (unnecessary) jigsaw. Let's look at the five main steps required for this: First you need to make a bushing - a basic and complex element in its structure. The taken plate needs to be bent and turned, then carefully drill a hole into which the thread will be inserted. After this, you need to remove the wire leading to the hole, and then find suitable connectors and carefully solder them into the gap area

It is important that all further work using the finished cutter is carried out with insulated wires. After that, we connect the thermal cutter. The old jigsaw needs to be cut into two parts

In its upper part we install a claw plate on the screws, which had to be prepared in advance. And using self-tapping screws we connect the lower part to the base. Insert the sleeve into the foot. We mark the point under the hole of the sleeve from the hole using a square (or a plumb line). We make a hole in the base with a diameter of 5 mm. Straighten the nichrome wire. First, turn on the burner at full power and touch the nichrome wire with its wires. It is important that the distance between the wires is equal to the height of the device. At the same time, if the device hums or makes strange sounds, and the thread does not heat up (this is a consequence of insufficient resistance), then you should find a wire of thinner thickness.

Making a laser cutter

First you need to remove the laser cutter from the drive. This work is not difficult, but you will have to be patient and pay maximum attention. Since it contains a large number of wires, they have the same structure

When choosing a drive, it is important to consider the presence of a writing option, since it is in this model that you can make notes with a laser. Recording is done by evaporating a thin layer of metal from the disc itself. In the case when the laser is working for reading, it is used half-heartedly, illuminating the disk

In the case when the laser is working for reading, it is used half-heartedly, illuminating the disk.

Laser cutting diagram.

When dismantling the upper fasteners, you can find a carriage with a laser located in it, which can move in two directions

It should be carefully removed by unscrewing; there are a large number of detachable devices and screws that are important to carefully remove. For further work, a red diode is required, with the help of which burning is carried out

To remove it, you will need a soldering iron, and you also need to carefully remove the fasteners

It is important to note that the irreplaceable part for making a laser cutter should not be shaken or dropped, therefore, it is recommended to be careful when removing the laser diode

To remove it, you will need a soldering iron, and you also need to carefully remove the fasteners

It is important to note that the irreplaceable part for making a laser cutter should not be shaken or dropped, therefore, it is recommended to be careful when removing the laser diode

Once the main element of the future laser model is removed, you need to carefully weigh everything and figure out where to place it and how to connect the power supply to it, since the diode of a writing laser requires much more current than the diode from a laser pointer, and in this case you can use several ways.

Next, the diode in the pointer is replaced. To create a powerful laser, the original diode must be removed from the pointer, and a similar one from the CD/DVD-RW drive must be installed in its place. The pointer is disassembled in accordance with the sequence. It must be untwisted and divided into two parts, with the part that needs to be replaced on top. The old diode is removed and the required diode is installed in its place, which can be secured with glue. There are times when difficulties may arise when removing the old diode; in this situation, you can use a knife and shake the pointer a little.

Laser pointer diagram.

The next step is to make a new case. To make the future laser convenient to use, connect power to it and use a flashlight body to give it an impressive look. The converted upper part of the laser pointer is installed into the flashlight and power is supplied to it from rechargeable batteries, which is connected to the diode

It is important not to confuse the polarity of the power supply. Before assembling the flashlight, the glass and parts of the pointer must be removed, as it will poorly conduct the direct path of the laser beam

The last step is preparation for use. Before connecting, you need to check that the laser is securely fastened, that the polarity of the wires is connected correctly, and that the laser is installed level.

After completing these simple steps, the laser cutter is ready for use. This laser can be used to burn paper, polyethylene, and to light matches. The scope of application can be vast, everything will depend on your imagination.

Line cutting cutter

c http-equiv=”Content-Type” content=”text/html;″>lass=”article_show_context_1″>

To create such devices, you should prepare a workspace. Usually a table is chosen for such purposes. Two vertical risers are attached to it. Each of them must have an insulator. It is necessary to stretch a nichrome thread between the insulators. A freely hanging load is suspended from it. The nichrome thread is connected to the contacts connected to the step-down transformer.

The operating principle is quite simple. The nichrome thread heats up when connected, which makes it easy to cut foam. Thanks to the suspended weight, the thread remains taut. A weight is necessary because when heated, the thread begins to sag.

The moving foam is cut with nichrome thread quickly and evenly. How thick the processed sheets will be depends on the height of the thread above the working surface of the table. The main thing is that the foam is fed at the same speed throughout the entire cutting period.

To cut sheets vertically, you will need to use a cutter of a different design. In it, the cutting wire is tensioned in a vertical position. In this case, the working surface is made of chipboard. You need to attach a frame to it. It is better if this element is made of a metal profile. However, wooden blocks will also work well.

The frame is equipped with a paw-holder, on which the nichrome wire is suspended. A weight is attached to its end. The wire is passed through a hole made in the working surface. To prevent it from touching the wood, the hole is protected from the inside with a metal hollow tube.

When using thermal cutters, foam plastic is not only easily cut into specific blocks. From large slabs you can cut out various geometric shapes, such as a square, a semicircle, a triangle. Before work, just run a marker along the surface of the slab, marking the cut line.

Thermal methods for cutting foam plastic

Cutting material using a thermal cutter is also a fairly popular method. The instrument itself has the appearance of a nichrome thread, which is laid on a frame in the shape of a frame. When an electric current passes through the nichrome wire, the metal surface heats up and the foam begins to melt. There are several types of cutter designs. The simplest option takes the form of a nichrome string stretched over ceramic insulators, which are attached to the edges of a frame made of wood or metal.

Using this tool, you can cut not only foam boards, but also wooden slats, plastic pipes, as well as any material that melts or decomposes at temperatures up to 270°C. If you need to cut sheets with a significant length of cut, then it is much more comfortable to use the machine, which looks like a thread stretched in a vertical position on a textolite stand.

To control the heating of the nichrome string, an LATR or rheostat is used. Excessively high surface temperatures can cause melting and even lead to fire of the insulation. The advantage of this method is the complete absence of dust and debris, and the cut site itself takes on a melted appearance, outwardly reminiscent of alkyd varnish treatment.

If, in the process of working with foam plastic, there is a need to cut off only small parts of sheets, for example, when making models and sculptures, then the best option is to use an attachment for a powerful electric soldering iron.

In addition, lasers are used to cut this material. In some cases, it is even used at home. For this task, an ordinary LED laser with a power of 2-5 W is used, through which it is possible to cut foam boards along any desired trajectory. At the moment, using such a tool, you can cut paper and foam plastic within 10-15 minutes, which is why it is quite difficult to process a significant volume of material with it.

Having familiarized yourself with the different options, you can not only find out what is better for cutting polystyrene foam at home with your own hands, but also choose the most suitable method for use, through which it will be convenient to cut it.

Video:

You may be interested in:

How to glue foam plastic to the ceiling: frame and frameless fastening

How to cut penoplex at home: choosing the right tool

How to insulate a floor under linoleum: optimal materials for installation

Shape cutter

When working with large foam sheets, using a stationary cutter will be difficult. Such panels hardly fit on the desktop. In these cases, a handheld foam cutter is used. This tool is often made from a jigsaw. The cutting blade in these tools should be replaced with nichrome wire.

It’s quite easy to build such an electric cutter with your own hands. To make cutting shaped elements more convenient, you can make several devices with different shapes. First, remove the cutting blade from the jigsaw and connect the wire to the handle. The voltage will be low, but the handle and other metal parts should be insulated. Nichrome wire is connected to the cable. Nuts are used for this. The wire is bent in a certain way.

You can use a soldering iron as a cutter for shaped cutting of foam plastic. It needs to be modified a little. The device already has an electrical wire in its design. To create a foam cutter from a soldering iron, you will need to replace the element that heats up with nichrome wire.

This device is highly convenient to use. Thanks to this product, it is possible not only to cut slabs of material into smaller sheets, but also to make recesses in them.

Types of electric cutters

The electric foam cutter can be used for a variety of purposes. This will determine the type of design and overall performance characteristics of the equipment. There are three main types of homemade cutters.

The first category is used for linear cutting. The second group includes cutters that perform shaped cutting of material.

Designers use them. This type is used less frequently for home repairs. There is also a tool with a metal working plate.

Such equipment must have a step-down transformer in its circuit. It must be rated for a minimum power of 100 watts.

The secondary winding of the transformer must have a cross-section of at least 1.5 mm. It must withstand a voltage of 15 V. In this case, you can achieve high performance results.

Metal plate cutter

There is another way to convert a soldering iron into a foam cutter. To modify the tool, you simply need to replace the tip with a copper plate. Steel will also work, but it takes longer to heat up and is more difficult to sharpen. However, with proper sharpening, a steel plate can cut any synthetic material, including polystyrene.

One side of the plate must be carefully sharpened. Sharpening can be done on both sides. It is necessary that the sharpening angle is not too large. The cutting of the material is carried out not only by the blade, but also by the blade of the plate. Such a cutter has one drawback - you will have to experimentally find the optimal heating temperature for the knife.

Machine design

The base of the device for cutting foam plastic 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 40x60 cm. With this size of the base, it will be possible to cut foam plates up to 50 cm wide. The base can be made from a sheet of plywood, a wide board, and the cutting wire can be secured directly to the desktop or workbench.

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

The ends of the nichrome wire are attached to springs mounted on M4 screws. The screws themselves are screwed into metal posts 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 would not extend beyond the bottom side of the base, and when fully unscrewed, it would provide a foam cutting 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 stand into the base, first a hole is drilled in it, with a diameter 0.5 mm smaller than the outer diameter of the stand. In order for the posts to be easily hammered into the base, the sharp edges from the ends were removed using an emery column.

Before screwing the screw into the rack, a groove was machined at its head so that the nichrome wire could not move arbitrarily during adjustment, but would occupy the required position.

To make a groove in a screw, you must first protect its threads from deformation by putting on a plastic tube or wrapping it in thick paper. Then hold it in the drill chuck, turn on the drill and attach a narrow file. In a minute the groove will be ready.

To prevent nichrome wire from sagging due to elongation when heated, it is secured to the screws through springs.

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

After preparing all the fasteners, you can fasten the nichrome wire. Since the current consumed during operation is significant, about 10 A, for reliable contact of the current-carrying wire with the nichrome wire, I used the fastening method by twisting and crimping. 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. Wires for connecting nichrome wire can be found in 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 of two with a cross-section of 1 mm2, connected in parallel.

After removing the insulation from the ends of the wires to a length of about 20 mm, the copper conductors are wound onto a string of nichrome wire at the point where it is attached to the spring. Then, holding the nichrome wire by the loop with pliers, the wrapped copper wire is wrapped with the free end of the nichrome wire in the opposite direction.

This method of connecting a current-carrying copper wire with a nichrome wire will provide a large area of contact between them and will eliminate strong heating at the junction when the foam cutting machine is operating. This was confirmed by practice: after prolonged cutting of foam plastic, the PVC sheath of the current-carrying wire did not melt, and the copper wire in the connection area did not change its color.

To be able to adjust the thickness of cutting foam on the device, the outlet of the current-carrying conductors is made with a loop. To prevent the wires from interfering during operation, they are passed through holes in the base and secured on the back side with brackets. The same brackets are nailed to the corners of the base as legs.

The current supply wires of the cutter are twisted together to avoid tangling. At the ends of the wires for connection to the power source, plug-in terminals are sealed.

conclusions

Making a foam cutter with your own hands is quite simple. The methods listed above will help you understand the structure and operating principle of the foam cutter. Such devices are practical and easy to assemble. Each method has its own advantages, so home craftsmen can choose the most suitable one, depending on the available materials.

It is important to exercise extreme caution when working with such power tools. This poses a risk of electric shock. Some homemade cutters are also used for cutting polystyrene foam.

Some homemade cutters are also used for cutting polystyrene foam.

(No ratings yet)

What to sharpen

To sharpen any object, you need a material that is harder than it or at least the same in hardness. Finding a material harder than zirconium ceramics is quite difficult. The most suitable are diamond coated tools. Can be used:

specialized sharpeners for ceramics;
electric sanders;
diamond paste.

Paying attention to the problem of sharpening, the Japanese company Kyocera has released mechanical and electric sharpeners. This company initially specialized in the production of fine ceramics, so it knows all the nuances associated with its use and maintenance.

Although the cost of sharpeners is quite high, if you love ceramic knives and prefer them over all others, this sharpener is worth purchasing.

There are other, mainly Japanese, American and Chinese, manufacturers of sharpeners

If you choose them, always pay attention to what blade thickness the devices are designed for, what type of knives can be sharpened and at what angle. Some sharpening models can even straighten small chips

Manual sharpeners are less expensive, but to use them you need to have sharpening experience and some dexterity.

In addition to special sharpeners, you can use an electric sander to sharpen a ceramic knife at home. It is imperative to install diamond-coated abrasive wheels. The grain size should be 40 microns or less. The abrasive paste should have a grain size of 5 microns or less.

Features of work

While learning how to make a manual foam cutter yourself, it is also necessary to consider the operating features of such equipment. As mentioned above, such an instrument has a string. It heats up and melts the surface of the foam.

This material reacts quite poorly to heat.

Therefore, it is important to maintain the technology of the entire process. Cutting with a hot thread is quick

This allows you to achieve high quality cuts.

It's easy to check the string's heating level. To do this, a test is carried out on a test piece of polystyrene foam. If, when immersing the thread, long pieces of material remain on it, it has not yet warmed up enough. If there is no foam on the string at all, then the temperature is too high. In this case, you will have to cool the instrument a little. With proper heating, you can perform fast, accurate cutting.

How to cut plastic with a special knife

You can use a special knife for cutting plastic if the thickness of the material being processed is up to 3 mm. Thicker sheets are cut using other methods.

Place a ruler along the line and draw a knife along the guide so that a groove is formed on the surface of the sheet.
Then the knife is passed several times along the recessed surface.
Afterwards, a sheet of plastic is placed on a hard surface with the cut facing up so that it is located along the edge of the tabletop.
To fix the position of the sheet, it is recommended to use clamps.
It is necessary to quickly and evenly drive the hanging section of plastic down, thus deepening the groove along the entire length until a crack appears that runs through the entire thickness.

As a rule, the result is a straight and almost smooth edge. The process is identical to the glass cutting process. The difference is that you can mark a cut line on the surface of the plastic several times.

Shaped cutting of foam plastic

Foam plastic is one of the most popular finishing products. Various figures cut from such material are especially popular. Volumetric foam compositions are used as architectural decoration, to create advertising elements, and various design structures for interior decoration.

Figure cutting is carried out using laser systems and special CNC machines. Each device has its own advantages and features of use:

Laser cutting. Processing foam plastic through radiation allows you to create 2D and 3D shapes of various shapes. This cutting method ensures the minimum cut thickness, helping to increase the detail of products. The entire process on laser CNC equipment is fully automated. Therefore, in the process of cutting the material, defects and errors are eliminated.
String processing. The formation of volumetric products occurs using the thermal effect of strings made of nickel-chrome. This method of cutting foam ensures accurate cuts according to given sketches. The cost of string processing of cellular material is much cheaper than laser cutting. All actions on the machines are controlled by a special computer program.

Using modern 3D foam cutting equipment, you can produce shapes of varying complexity in a short period of time.

Types of laser cutting

Laser systems consist of three main parts:

Working (active) environment. It is a source of laser radiation.
Energy source (pumping system). It creates the conditions under which electromagnetic radiation begins.
Optical resonator. A system of mirrors that amplify laser radiation.

Based on the type of working environment, lasers for cutting are divided into three types:

Solid state. Their main unit is the lighting chamber. It contains an energy source and a solid working fluid. The energy source is a powerful gas-discharge flash lamp. The working fluid is a rod made of neodymium glass, ruby or yttrium aluminum garnet doped with neodymium or ytterbium. Two mirrors are installed at the ends of the rod: reflective and translucent. The laser beam emitted by the working fluid is repeatedly reflected inside it, amplified during reflections, and exits through a translucent mirror.

Fiber lasers also belong to the solid-state type. In them, radiation is amplified in glass fiber, and the energy source is a semiconductor laser.

This is how a solid state laser works

Gas. In them, the working fluid is carbon dioxide or its mixture with nitrogen and helium. The gas is pumped through a gas discharge tube. It is excited by electrical discharges. To enhance the radiation, a reflective and translucent mirror is installed. Depending on the design features, such lasers are available with longitudinal and transverse pumping, as well as slot lasers.

This is how a gas laser with longitudinal pumping works

Gas-dynamic. These lasers are the most powerful. In them, the working fluid is carbon dioxide, heated to 1,000–3,000 °K (726–2726 °C). It is excited using an auxiliary low-power laser. Gas is pumped at supersonic speed through a channel narrowed in the middle (Laval nozzle), sharply expands and cools. As a result, its atoms pass from an excited state to a normal state and the gas becomes a source of radiation.

Scheme of operation of a gas dynamic laser

How and how to cut polystyrene foam at home

Foam plastic is a building material used for interior and exterior decoration. It has excellent heat, hydro, and sound insulation properties. Polystyrene foam is made from polystyrene (PS grade) or polyvinyl chloride (PVC).

The quality of processing when cutting foam plastic depends on the sharpness of the cutting tool. A blunt instrument leaves ragged indentations on the surface being treated. The final finishing of the surface is carried out with fine-grained emery cloth, securing it to a flat block.

Polystyrene foam is brittle and friable.

Methods for cutting foam plastic.

- using nichrome wire: the wire is stretched between two “studs” fixed on a flat surface, for example, a sheet of chipboard. This is done so that the distance between the wire and the surface can be easily changed. The ends of the wire are connected to the terminals of the power supply, which supplies a small adjustable voltage (enough to 12 V). In this case, it is better to use a 220/24 V step-down transformer. The foam is laid on the surface and smoothly moved so that the hot wire cuts off the required part from it. The cut is even and smooth (“fused”). This method allows you to cut foam plastic very quickly and efficiently, not only crosswise, but also longitudinally.

-using a string that is heated by a small current passing through it. The string is heated with a soldering iron or burner. You can take a spiral from an electric stove, cut it and apply current through an autotransformer, but not 220V, but 12 - 36 V. Do not forget that the wire (string) considerably lengthens when heated - it must be spring-loaded or a system with a counterweight (weight tensioner) must be made. by analogy with the previous method.

Cutting foam with a string

- using a simple knife (it’s difficult to cut this way): you need to sharpen the knife and heat it up. Under the action of a hot knife blade, the foam will begin to melt, and its edges will be perfectly smooth. This method is used for foam plastic about 10 cm thick.

- a hacksaw for wood. When sawing with a hacksaw (necessarily with fine teeth), do not make quick movements, because polystyrene foam is a good heat insulator, and the heat generated during friction is almost not removed. As a result, the material heats up and “grabs” the cutting blade. Dense foam plastic can be processed well with blunt knives.

- an electric jigsaw, consisting of a frame and a filament stretched across it. The jigsaw does not produce any sawdust. But it is not easy to make, despite the fact that it looks quite simple in appearance. It is much easier to use an ordinary soldering iron to cut foam plastic, slightly modifying it. Remove the tip from the soldering iron, and instead insert a cutter made of copper wire approximately 2 mm thick. Bend the part of the wire that is inserted into the socket into a spiral; its outer diameter should correspond to the inner diameter of the socket.

It is best to make two replacement cutters. Leave one completely straight, and bend the other to the shape of the future part. A straight cutter is convenient for cutting off the bow and stern; a curved cutter is useful for cutting out the bottom, smoothing out irregularities, and making grooves and recesses.

- using a thin steel string with a diameter of 0.5 mm, at the ends of which wooden handles are attached. Pre-mark the foam block on both sides with lines along which the cut will go, and, with a handy hand, begin sawing, moving back and forth at a fast pace. As a result, it heats up and begins to melt the foam, cutting it.

Cutting material using a hot tool

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

You need to make sure that the length of the knife is greater than the thickness of the sheet that will need to be cut. Next, you need to mark the lines on the sheet along which it will need to be cut. The next step is to heat the knife using a gas stove or a special gas burner

Carefully draw a hot knife along the intended line; the foam will begin to melt and cut clearly along the line.

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

But if your goal is to cut off a small piece, then a hot knife will allow you to do this very quickly and without wasting extra money and time

Please note that after cutting, the knife should never be used in the kitchen or at home, as the foam contains toxic substances

Knife

A simple soldering iron cutter

If you need to make quite a lot of foam blanks, but don’t want to make an overly complex cutter, then you can use its simple analogue, which works on the basis of a regular soldering iron.

It is important to choose a soldering iron that is not too powerful, since its temperature is excessive for normal sheet cutting. If the power is too high, the foam will smoke a lot, smoke, and be difficult to cut

The next step will be to select and install a nozzle on the tip of the soldering iron, since the standard tip is in no way intended for these purposes. We need to find or make our own long and flat tip, which will look like a small knife blade, but less sharp. Copper wire folded several times is good for making such an item. Another option is to simply take out the tip of the soldering iron and shape it into the desired shape.

Next, the tip is tightly fixed to the tip of the soldering iron and you can start cutting.

The soldering iron is inserted into a socket, heats up and cuts the foam using a similar principle to a hot knife. The main advantage of this method is that there is no need to constantly heat the knife; cutting can continue continuously.

Soldering iron cutter

Homemade thermal cutter from a soldering iron

Diagram of a thermal cutter made from a soldering iron: 1 – safety screen, 2 – 2 M6 bolts with clamps, 3 – brackets, 4 – stand, 5 – section of a straight tip, 6 – copper plate, 8 – wooden board, 9 – support legs.

To process foam plastic, not only heated wire can be used, but also a heated metal plate. The basis of this thermal cutter (see Fig. 7) is a conventional soldering iron with a power of 60 W, designed for a voltage of 220 V. Instead of the usual tip, this device uses a plate knife, which is the main element of the cutter. It can cut not only foam plastic, but also any hot-melt synthetic material.

The base of the device is a sheet of heat-resistant plastic, plywood or a wooden board (8), to the bottom of which support legs (9) are attached. They are needed because in the middle of the base there is a gap into which the heated knife is lowered. Opposite the slot at the edge of the pad there is a stand (4) with brackets (3) for installing a soldering iron.

The stand is made of a metal tube, and the brackets are made of 2 M6 bolts with clamps (2). A safety screen (1) is also attached there, which protects the worker’s hands from burns.

The thermal cutter knife is a copper plate (6) pressed into the cut of the straight tip (5) of the soldering iron. The cutting edge of the knife is sharpened at a slight angle. It can be sharpened on one or both sides. The degree of heating is selected experimentally.

Methods for sharpening a disc for woodworking

The following methods ensure efficient and safe sharpening of circular saws.

Grinder - step by step instructions

Special machines for sharpening circular saw blades are expensive and require certain skills to operate, so angle grinders, that is, “grinders,” are an effective and affordable alternative.

To fix the disc, a special smooth stand is used, which is designed taking into account the fact that the tooth must be perpendicular to the grinder disc and have a minimum deviation from it.

For sharpening using a grinder, the following algorithm is used:

The grinder is equipped with a grinding disc, and the disc to be sharpened is attached to the platform.
The grinder is held by hands or using a holding device.
The cutting edge of the circular tooth is processed with a grinder. In this case, a light, uniform movement is performed.

Evidence that the edge has been sharpened will be a visual update of the edge - it will no longer be darkened.

It is forbidden to turn on the grinder if the disc is placed in the throat between the teeth of the disc being sharpened.

File

If a file or needle file is used as a tool, then all sharpening activities are the same as when using an angle grinder. In addition, to maintain the sharpening angle, a special template is required, which is used as a guide plane between the tooth and the file.

But at the same time, the work will take much longer, since circular saws use carbide attachments.

Special machine

Machines for turning circular saw cutters are complex engineering and technical devices, which, in addition to mechanisms, are also equipped with automatic electronics.

These machines allow you to perform the most effective restoration of cutting edges in compliance with all the necessary configurations. The efficiency of the machines is explained by the following criteria:

Possibility of automating the sharpening process.
Saving sharpening angle parameters for each cutter.
All cutters are sharpened identically with minimal error.
Possibility of complete restoration and restoration.

For sharpening on a machine, the saw blade is placed in a special support and secured.

The sharpening parameters are selected, which are provided by special mechanisms for tilting the disc being sharpened or tilting the sharpening disc in the machine.

The disc to be sharpened is placed in the working area of the device.

The machine starts up and sharpening is carried out automatically.

Homemade machine

To operate effectively, homemade machines must include the following components:

Angle grinder (grinder) as a direct sharpening device.
Support for securing the saw blade of a circular saw.
Mechanisms to allow the support to tilt to adjust the sharpening configuration.
The entire mechanism is fixed to a frame, which can be a channel or an I-beam.

The operating process is similar to using the original sharpening machine with the only difference - the circular blade is fed to the working area of the device manually.

Stages of creation

Cutting part. To do this you will need nichrome wire, approximately a spiral with a diameter of 0.6 mm. It can be taken from old electric stoves or other heating electrical appliances. The length of such a wire should be 14 cm (its resistance will be 2 ohms).
Transformer application. For everything to be correct, the first step is to calculate the voltage and current for heating the cutting part. This can be done using the formula - Ohm's law I=U/R. Thus, you can determine the power of the power transformer.
Making a cutter. The base can be made of any metal, but its length must be at least 11 cm. Next, an insulator - a PCB plate - must be attached to the end. Now fasten the contact groups along the edges of the plate; they can be removed from the electrical outlet. It is into these contacts that it will be possible to attach spirals of different shapes.
How does the cutter work? After the cutter is plugged in, the wire will heat up and become slightly reddish in color. This is exactly what matters, since a heated cutter will make it possible to easily and quickly cut the foam, which will not peel off.

It is important to know: having received such a device, in just three minutes you can cut the required shape from a sheet of foam plastic.

Be sure to follow all safety rules so as not to injure yourself and others. After all, the power of the cutter is enough to damage any part of the body during operation. And connecting to electricity further increases the risk of injury.

Basic forms and characteristics of triggers on homemade knives

Beginners, as a rule, having a blank and all the necessary tools, cannot decide which trigger is the most versatile. At least for a kitchen knife. But don't worry, there are a few of the most common types of descents that we will now look at:

The most common, and is made from the butt itself, is wedge-shaped. It is usually used in the kitchen.
Another quite popular type is also wedge-shaped, it comes from the butt itself and goes into the cutting edge. But if you sharpen it, it will automatically go into type number 1; during sharpening, a cutting edge will be formed separately from the trigger. Or sharpen the entire trigger, which is quite problematic.
Quite a characteristic shape for many knives. The blade is flat, and the descent begins from the middle or slightly higher to the butt. Sharpening is quite easy.
A very interesting option, and quite often used wedge-shaped bevels and cutting edge, the knife is quite durable and the cut is good. The slopes and edges are very harmoniously located.
The cutting edge is formed by a double wedge. The slopes are wedge-shaped, but the material between them and the cutting edge is removed. It cuts dense materials very well, but is difficult to sharpen, one might say, for professionals.
Lenticular concave slopes. The cutting edge is like a continuation of the edge between the blade and the bevel towards the tip. They can start almost from the butt itself. The second name for sharpening is “razor”, it is used for straight razors.
One-sided sharpening acquired the name - chisel sharpening. Sharpening is quite easy. A knife can only be wielded with one hand. In this case, the bevel should be on the side of the working hand.
The shape resembles trigger number 3, but there are none as such, a straight blade and an immediate cutting edge. More suitable for chopping products.
Convex lens-shaped slopes, smoothly turning into the cutting edge. There are two names for sharpening: “bullet-shaped” and “ogive”. It is difficult to cut with a blade, it gets stuck in the material, but it has excellent cutting characteristics. Difficult to manufacture, also an option for professionals.

Basic forms of triggers on knives.

To begin with, you can try on any unnecessary workpiece, make descents No. 1 and No. 3. They are simpler than others and will find use in your home, as an option in the kitchen. And once you’ve gotten the hang of it, you can begin to tackle more complex types of sharpening.

Step-by-step instructions for making your own machine and cutting foam plastic

Step 1. Preparing the tabletop.

You can take any piece of chipboard of the required size as a tabletop for a machine for cutting foam plastic with your own hands. The surface on which the foam will move must be smooth. Holes for the racks are drilled in the tabletop. It is convenient to use metal pins with threads 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 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 below, under the tabletop, the wires are connected to metal stand rods: the wire is wound around the lower end of the pin and pressed with a bolt.

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

Step 3. Fastening the nichrome spiral

. A 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 to tension the nichrome thread during operation. The fact is that when heated, the nichrome thread lengthens and sags. A thread in this condition will not produce a quality cut. Therefore, the thread is fixed in an initially tense state, so that the spring is slightly stretched.

To fasten the nichrome thread to the pin, washers with an internal 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 inner diameter side 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 placed on the first pin. The second washer is put on the second pin and a nichrome spiral is threaded into the drilled hole. Next, it is tightened so that the spring stretches and fixed.

Step 4: Cutting the foam.

To spread 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 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 lead to rapid filament burnout. Here, a balance between tension, thickness and length of the thread must be selected experimentally. The thread should not overheat 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 advisable to reduce the voltage, otherwise the thread will not last long in this mode. Of course, smooth adjustment is easy to do if LATER is available. But if it is not there, then a laboratory power supply can 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 device is safe.

Step 4: Cutting the foam at an angle.

Sometimes it becomes necessary to cut the foam so that one side is higher and the other is lower.

To do this, the spiral is set at an angle with the required parameters. In this way, foam sheets of various sections can be obtained.

Useful video

We also recommend:

Polystyrene foam is a durable, lightweight material that has thermal insulation properties. Carrying out work with such insulating material seems to be a very simple task. But still, there are some nuances when working with the material. Since it is made in the form of large slabs, trimming is necessary quite often. Trimming can be done with an ordinary kitchen knife, but it will not cut beautifully. It is for this reason that craftsmen recommend using a special foam cutting machine for this purpose.

What material to choose for cutting

Before we start working with the material, we need to find out what kind of foam there is, what type of foam is best used for cutting at home.

Polystyrene unpressed

This is the most common and familiar polystyrene foam, which is familiar to us from technology packaging. The material consists of many small white balls that are tightly connected to each other, but can become separated from mechanical stress. It is very widespread and is most often used in the manufacture of products at home.

Polystyrene pressed

This is a similar type of foam, which is simply additionally pressed. Because of this, it has a much denser structure, it is more difficult to crumble, but such material also costs much more than its non-pressed counterpart. Due to the high price, pressed polystyrene foam is not widely used, but for some products it can definitely be used, since its structure is quite smooth.

Polystyrene extruded foam

Polyvinyl chloride foam

The rarest and most unused type of this material, which has one interesting property - the ability to extinguish on its own when ignited. It does not emit hazardous substances, but if it does catch fire, the smoke from it is very dangerous and can pose a health hazard.

Homemade thermal cutter for figure cutting

Diagram of a hand cutter: 1 – cutting wire, 2 – wooden block, 3 – spring, 4 – handle.

For cutting sheets of large size and thickness, or if it is impossible to place the foam on the workbench, a hand-held electric cutter is useful. It can also be made by hand (see Fig. 5).

Its basis is a frame made of wooden blocks (2), hinged. A cutting wire (1) is stretched between the lower ends of the vertical bars. In a taut state, it is supported by a rubber band or spring (3). When working, the tool is held by the handle (4).

A similar tool can be made on the basis of a hacksaw or a hand jigsaw, where the file is replaced by a cutting wire. On one side there should be a tension spring and an insulator.

Thermal cutter, the device of which is shown in Fig. 6, allows you to make indentations in the foam, cut out cavities in its thickness, chamfer, etc. With its help, it becomes possible to handle this material in much the same way as a sculptor handles clay.

Diagram of a manual thermal cutter: 1 – nichrome cutting wire, 2 – screw with nut and washer, 3 – textolite handle 4-5 mm thick, 4 – electrical cord.

This device is designed quite simply:

nichrome cutting wire (1);
screw with nut and washer (2);
textolite handle 4-5 mm thick (3);
power cord (4).

To expand the capabilities of shaped cutting of foam plastic, it makes sense to make several similar cutters with tips of various shapes (see Fig. 6).

A good shaped thermal cutter for foam plastic can be a wood burning device if you connect a tip made of nichrome wire of the required shape to it. For the same purpose, you can use a pulse soldering iron if its standard tip is also replaced with a piece of thick nichrome wire.

Useful tips

During cutting, the speed of material movement should be medium. 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, you move it very slowly, the edges of the cut out figure will melt.

If polystyrene foam is required to insulate a 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 you have a Mayak stereo tape recorder lying around in the attic since Soviet times, then do not buy a transformer, but take it from it. It is just suitable, because... supplies 24 Volts.

In cases where work is carried out in a lack of electricity, connect three 9-volt crowns to each other and use them. Thus, the device will be able to function for 30-40 minutes.

But using car batteries for this purpose is strictly prohibited. Despite the low voltage, they have a very high current strength, which can burn the string and it will simply burst. This will happen in a good situation, but in a bad situation it will splash hot metal.

DIY tools for cutting foam plastic

Home insulation materials are always available for sale. It is best to glue the foam onto a flat wall, but if protrusions are found, you will have to adjust the shape of the foam. Foam cutting is carried out both with purchased equipment and with self-made equipment.

To build a structure, it is important to select parameters and drawings. The type of work also depends on the design and its dimensions

Cutting polystyrene foam at home is carried out using improvised means, the main thing is to choose the materials correctly. It is important to comply with safety requirements; when cutting, the product may slip and damage the limbs.

Homemade thermal knife for cutting

It is possible to adjust the shape of insulation products, cut out small products and blanks using a thermal knife. To cut foam plastic you will need:

A crown-type battery with an output voltage of 9 volts, or a set of finger-type products.
Nichrome fishing line stretches between the plates, length no more than 10 cm.
Several wires will connect the ends of the wires to the battery.

The simplest cutter can be assembled from available materials; it will help chamfer corners and perform the necessary adjustment of polypropylene parts. It is necessary to install a power button that will activate the device, this is done for convenient, safe operation.

DIY nichrome cutter

Do-it-yourself production requires the availability of certain means. In order to efficiently assemble a tool for cutting foam, you will need:

nichrome wire, it can be purchased in radio parts stores of the required size;
a 12-volt step-down transformer, which can be used as a computer power supply or a car battery charger;
long knitting needle;
rheostat, which makes it possible to regulate the current strength;
The electrical wires are long enough for the connection.

https://youtube.com/watch?v=DuKzOuVNqHQ

The device can be mobile or mounted on a table. The frame is made of wood, the wire is installed at a height of 10-15 cm, on the adjusting screws. The screws that secure the nichrome wire must be of a suitable length to adjust the height to the required level. A weight is suspended from one side of the screw to tension the wire for a straight cutting level.

Exposure to current leads to splitting of the wire; the foam is easily exposed to temperature effects. The edges are sealed, this prevents the structure of the material from disintegrating. Cutting the foam begins after the appearance of a red tint on the wire; there is no need to bring the incandescence to a high level, in these cases the width of the cut will be too large.

Nichrome cutter

When performing the procedure, you should use personal protective equipment, a mask, and gloves. The melting process produces toxic fumes.

Design features and principle of operation

The string expands when heated, adding up to 3% in length; cutting with a sagging cutter will not be of high quality, so a special mechanism is added to the design. When operating at low frequencies, it is possible to use a spring; it will gradually tension the wire to the desired state. Massive use means rapid stretching, so it is better to use a suspended weight on one side of the string.

Nichrome cutter design

The foam cutting device is powered by energy sources with an output voltage of 12 to 36 volts. The most successful option is a laboratory transformer. The device is capable of withstanding high loads and smoothly adjusting the output voltage.

How to do it yourself

And to do this, you will need a piece of foam. For example, you can use foam from TV packaging. It is necessary to draw on it using a ruler, compass and ballpoint pen the places where holes will need to be made in the future.

This is where the need for an electric cutter comes into play. After all, it will be difficult to perform this action without spoiling the foam sheet without such a tool. Let's consider one of the options for how to make a device of this type at home.

A homemade cutting device can be of various designs. It is on it and the type of cutting that will depend on how exactly the cutter copes with its goals.

Tools for cutting foam plastic of different densities ↑

Tools for cutting foam sheets differ from each other both in functionality and in the complexity of working with them.

Unconventional cutting method - nichrome thread

All the methods presented above allow us to process polystyrene foam exclusively in a straight, even line. In situations where you need to make an unusual shape, a semicircle or a zigzag, you can use unconventional methods. For example, nichrome thread. With its help, you will learn how to cut foam plastic so that it does not crumble, with minimal time and physical costs.

First, you will need to do some preparatory work to assemble the necessary equipment. So, you should make sure you have a small spring, a 24-volt transformer and nichrome wire. The working surface of the table is set at an angle from 20 to 60 degrees. We stretch 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 movements. The only difficulty is assembling the necessary equipment, since not everyone has transformers.

Thus, there is nothing overly complicated about how and how to cut polystyrene foam at home. Even with an ordinary knife you can perform all the necessary operations. If you purchase better equipment, the processing process will take a minimum of time, without additional effort, noise and debris.

Advantages and disadvantages of the material

The best thermal insulation material - polystyrene foam - has many positive and negative properties. Its advantages:

This is a special insulation that is capable of high-quality soundproofing not only individual rooms, but also entire buildings.
It does not contain harmful substances, so the material is environmentally friendly.
Used as ceiling coverings. Decorative products have different textured patterns and colors.
Used during transportation. For high-quality sealing, the product is additionally sealed with polystyrene foam.
It can be transported, unloaded and stored without problems due to its light weight.
The material is resistant to fungi and mold.

Under the influence of high temperatures and some technical substances, the foam begins to collapse. Therefore, when working with the material, it is necessary to follow certain rules. Do not use gasoline, acetone or white spirit. The foam board will begin to crumble and collapse from the inside at air temperatures above +500 degrees. Because of this, in places where insulation is used, the temperature regime must be observed.

What is polystyrene foam and what is it used for?

Foam Sheets
Foam is a white material that consists almost entirely of air. It is used for packaging equipment, food, as a heat-insulating and sound-proofing material, as a basis for the manufacture of household items, logos and many other things. One of the main advantages of polystyrene foam is its low cost . Many people buy it in order to make some product from this material and sell it profitably. But even for an ordinary person, polystyrene foam will be very useful, because you can make a lot of things for your home from it. The main thing is to be able to work with the material correctly, as well as choose it for specific purposes.

Assembling a stationary vertical cutting machine

Using a stationary vertical cutting machine is more convenient than a manual one, because you only need to move the foam sheet. This promotes precision of movements.

To make the device, you need a flat and smooth table surface.

A block is attached perpendicular to it, and a wooden crossbar is attached to it at a right angle.
Using an angular ruler, mark the point where the filament will pass, and drill a hole with a diameter of 6 mm into which the wire is threaded.
The lower end of the string is put on a self-tapping screw, which is screwed in next to the hole.
A spring is attached to the top screw, and a nichrome thread is attached to it.

Types of foam shredders

You can choose the type of crusher for foam plastic based on the amount of material. If the main task is to obtain 1-2 small bags of crumbs, you may not need to assemble a special unit at all to complete it. It is enough to use a metal brush, which is used to rub sheets of foam insulation, or a homemade “grater” from a box with cells. This method will be ineffective, but will avoid costs.

It is better to immediately purchase high-quality material for roof vapor barrier than to redo all the work later.

The method for installing a vapor barrier on the floor is somewhat different from installing it on the roof.

Thermal cutter for foam plastic video

This video is about how to make a thermal cutter, which will be useful for various purposes in the workshop.
For example, you need to cut polystyrene or foam rubber evenly. An electric knife will cope with this task perfectly! For the future frame of the thermal cutter, we will take a piece of chipboard from old furniture. The design of this table requires legs. Next, drill two holes with a drill. Let's take a drill bit with a slightly larger diameter and make a recess for the countersunk head. Now everything is ready to tighten the legs with screws. It turned out to be a small table for the future cutter.

Now, with a pencil and a ruler, mark the place where the holes are needed. Take a drill with a diameter of 8 millimeters and make a through hole. A frame for tensioning the nichrome thread will be mounted in it. You need to make another hole in the center of the table. It will be much smaller in diameter than the previous one. Drill diameter 1 mm. They made a through hole.

Now you need a stud with an m8 thread. We saw off a piece of it to length. After some distance, bend the pin into the letter G. To prevent the pin from bursting during operation, you need to warm it up a little. The resulting angle is 90 degrees.

Now you can screw the powder nut onto the thread of the stud. It is needed for convenient fixation of the frame to the table. After the nut, put on the washer. You will need a bronze adapter with two screws to secure it. We fix the adapter into the holes that we drilled in the center.

DIY electronics in a Chinese store.

Of course, to power the device you need a powerful wire. You will also need a power button. We clamp one end of the wire into the adapter. Solder a contact washer to the other end. Now you can fasten it so that it is securely attached to the structure and the contacts at the base do not break.

We mount a frame made of studs into the hole. We put two washers on the lower part of the table, first the thrust washers and then the contact washers. Now you can tighten the nut. That's all. We clamp it with a wing nut and the frame is securely installed on the table.

We connect a switch to the gap in one wire. Cut off the excess piece from the wire. We clean the wires. Screw-on button. The switch is connected. It can be collected on site.

First, we thread the thread through the hole and fasten one end of the spiral into the adapter. We fasten it to the mounting bolt. With great stretch we place the spiral between 2 washers. We fix the contacts with a wing nut. That's all! The cutter is ready! It can be checked.

Power is connected – battery charger. This device can easily and accurately cut foam. To make the cut more even and accurate, use a guide. The cutter did a great job with the foam! No less successful with cutting foam rubber. Let's try to cut a plastic bottle. The thermal cutter cuts plastic parts well.

The simplest homemade foam cutter

This type of cutter is not difficult to make with your own hands. To do this, just take the thinnest guitar string and 4-5 large batteries for an electric flashlight. Having connected all the batteries in series into a single element, you need to connect a guitar string to its ends and secure it with electrical tape, closing the electric arc. Due to the electric current passing through the string, the string will heat up.

Image 1. Diagram of a cutter that allows you to cut flat sheets from a block of foam plastic.

At the point of contact with a string heated to the required temperature, the foam sheet will instantly melt, dividing into two halves, the cut of which will be fused and even. But for normal cutting, the string must be heated to a temperature of at least 120-150º. When working, it will not be difficult to determine whether the string has warmed up enough, since when cutting foam plastic, small stuck pieces will remain on the string. The longer such pieces remain, the lower the temperature of the string. But if they don’t remain on the string at all, then this means that this kind of thermal knife is heated more than necessary.

Such a primitive foam cutter can easily cut 2-3 large layers of material. But with large volumes of work, the batteries quickly run out, so in such cases, to cut foam plastic with your own hands, use a cutter powered by an electrical outlet.

Return to contents