What you need to know about cutting foam
When processing polystyrene foam, each of these balls slows down the cold knife, but it’s different if the knife is heated
Styrofoam is a cellular material whose structure consists of many dense, compressed bubbles. Bubbles are not well suited for mechanical deformation, as they will squeeze through even with a sharp knife.
It is not difficult to cut such figures on professional equipment with CNC and here the principle of processing foam plastic is the same as that of any thermal cutter
The only way to accurately cut such material is to use cutting tools heated to temperatures over 100 ° C. A lower temperature of heating will cause the material to crumple and tear under the cutter.
Cutting tool temperature over 200 ° C will lead to the fact that the edges of the cut will catch fire and burn.
By the way, properly assembled thermal knife can cut not only styrofoam, but also extruded polystyrene foam, polyethylene and other polymeric materials.
Assembling a simple cutter from a simple soldering iron
The picture shows the easiest knife for foam, made for 10 minutes from an ordinary soldering iron
There are situations when the foam plastic needs to be cut right now and there is no time to build a complicated machine. Exactly for such cases I propose a simple method of modification of an ordinary soldering iron into a cutter for styrofoam.
The instructions are very simple, and therefore the tool will be ready in 10 minutes, or maybe sooner.
If the wire was new, the first few minutes after heating, there will be a smell of burning. It’s okay. the lacquer will burn off the copper and already in a couple of minutes the hot knife for cutting foam plastic will not smell
Assembly of a nichrome thread hand torch
The picture shows the Styrofoam wire cutter and you can cut both straight and curved lines with it
Now that you know how to make a simple thermal knife from an ordinary soldering iron with your own hands, I offer the instructions for assembling a hand torch with a cutting part made of nichrome wire.
This cutter is as uncomplicated as a thermal knife, but it can be used to cut neat, shaped Styrofoam.
- Nichrome wire thickness of 0.8-1 mm;
- Two popsicle sticks or similar wooden strips;
- Two metal strips from a children’s construction set;
- Fastening bolts and nuts sized to fit holes in the metal slats;
- A block for two AA-format plastic batteries;
- Two AA-size finger-size batteries;
- A small size button;
- Soldering iron, hot glue gun, pliers, drill, screwdriver.
Remember about safety precautions, because the working surface of the cutter is heated above a hundred degrees, so it can get burned
Assembly of a stationary vertical cutting machine
The previous nichrome cutter is held in the hand when working. The model you will learn about now is stationary. That is, the fixture is stationary, and the foam will be hand-fed to the filament.
- Plywood with a thickness of 10 mm or more or flat sheets of chipboard;
- A 50×50 mm bar;
- A small turnbuckle;
- A metal plate with a thickness of at least 1 mm;
- Nichrome wire 0.8mm diameter;
- Power unit.
Turn the turnbuckle until the cutting nichrome wire is taut.
How to make a thermal cutter for tapes with your own hands
To make your own hands-hot knife for cutting satin ribbons will be required:
- A simple 30-60 watt transformer for halogen bulbs,
- Insulated wire with a cross section of 1.5 mm,
- A 12-13 cm long piece of nichrome wire,
- Bolts, screws, nuts.
6 steps for making a hot knife for cutting satin ribbon
- Re-convert the transformer to 5 volts, using the secondary winding.
- Make a rectangular shape enclosure from wooden blocks with a fiberglass cover, where to mount the transformer.
- Make the holders from galvanized bolts with a height of 90 mm and a diameter of about 6 mm. Fasten them parallel to each other on the body.
- Cut 12 mm holes with a hacksaw into the bolts of the holders for fixing the y wire, which is then wrapped around the bolts after inserting into the slots, and then clamped with the nuts.
- The tension of the wire when heated will be due to the elasticity of the device surface material.
- The front panel is equipped with an on/off toggle switch.
Cutter for linear cutting of foam sheets
To create a fixture with horizontal cutting of foam sheets, prepare a table. Attach a pair of vertical risers with insulators to it. Stretch a piece of nichrome wire between the risers, the end of which is connected to the transformer’s contacts.
When heated hot knife for cutting foam, the thread easily cuts the foam without difficulty, and with the help of a suspended weight remains taut. For vertical cutting the wire is stretched vertically, and on the working surface is fixed a frame made of metal or wooden bars.
Cutter for shape cutting foam plastic
Handling large sheets of foam with a stationary cutter is difficult, so it is better to use a hand knife to cut foam. It can easily be made from a jigsaw by replacing the cutting part with nichrome wire.
First of all, the cutting part of the jigsaw is removed. A wire is connected to the handle. They are insulated. A nichrome wire is connected to the cable using nuts. You can also use a soldering iron, replacing the heating element with a nichrome wire. Thanks to such a device it is easy not only to cut the foam sheets, but also to make hollows in them.
Metal plate cutter
To modify his own hands soldering iron in the hot knife for foam or synthetic materials can be used copper or steel plate, neatly sharpened on one side.
It is important that the angle of sharpening is small, because the material is cut by both the blade and the plate. Such a device has one drawback. the optimum temperature is selected by experience. Even plastic is easy to cut with such a hot knife.
Как сделать термолобзик своими руками How to make your own hands termofretsaw
Applications for nichrome wire
The specific properties of nichrome have found their application in various fields, both domestic and industrial.
All kinds of varieties of this alloy are used as heating elements for various devices: electric furnaces, dryers, thermocouples, as well as in ceramic products, performing the role of supporting framework.
Nichrome wire, as the main actuator of electric heating devices, is in most cases a spiral, through which an electric current of a given value is passed. This shape is recognized as the most optimal for these devices, as it allows to achieve greater heat transfer by increasing the length of the conductive element. The high degree of plasticity of the material presented significantly increases the life of such devices, due to the high resistance to deformation.
This heat resistant alloy is also used in various measuring instruments that require wire-type thermal elements. These include: rheostats, resistors, thyristors.
Where to get nichrome wire at home? This alloy is ubiquitous in various household appliances. Examples include electric heaters, hair dryers, soldering irons, toasters, and ovens. They are also used in electronic cigarettes.
Nichrome wire: selection criteria
The implementation of a project involving various types of electrical heating equipment presupposes a thorough analysis of nominal operating parameters, which is the starting point for calculating the key parameters of nichrome wire.
First of all, it is necessary to calculate the electrical resistance of the working element. It depends on three physical quantities, namely, the specific resistance of the material, its length and cross-sectional area. The formula for calculating the active resistance is as follows: R = ρ l / S.
To get the missing data, it is necessary to make a calculation of the length of the helix. Depending on the voltage applied to it, we should settle on the most optimal value of the wire length, its diameter, as well as the size of the core. To save yourself from time-consuming calculations, you can use the summary table showing the values of the coil length, depending on the diameter of the wire and core for nichrome with a diameter of 0.2 to 0.5 mm.
|D 0.2 mm||D 0.3 mm||D 0.4 mm||D 0,5 mm|
|D core, (mm)||Spiral length (cm)||D of the core, (mm)||Spiral length (cm)||D core, (mm)||Spiral length (cm)||D core, (mm)||Spiral length (cm)|
The table shown is applicable to the calculation of the coil length when using 220 V voltage. For example, for a wire with a diameter of 0.4 mm and a core diameter of 3 mm, the length of the spiral for a domestic electric circuit will be 40 cm. It is worth noting that with the help of this table it is not difficult to calculate the required value for 380 V. To do this, it is enough to pick up the necessary data and make a proportion of the following kind: 220 V. 40 cm / 380 V. x.
In case you do not have a measuring tool handy and it is not possible to determine the diameter of the wire, you can always use a simple but effective method. To do this, just take an ordinary pencil and wind the wire on it, pressing tightly coil by coil. In the case where 10 turns of the spiral are within 1 mm of each other, it is possible to determine the diameter of the wire. If the diameter of the wire is less than the length of the pencil, then the diameter of the wire will be 1 / 10 mm.
Sawing with nichrome wire. How you can make a nichrome electric jigsaw or cutter with your own hands Glow wire jigsaw
For those who do not have the ability or desire to use woodcarving sketches ornaments ordinary wood for composing map (propyl) carving in wood and the material is used plywood, sawing jigsaw is not always the best way to work.
Plywood. the material is quite fragile, it is easy to break off. And it is often sawn with the formation of unattended “rags” of fiber on the sides of the kerf. Not in addition, and for wood jigsaw is not always the best tool for woodcarving sketches on a plank, especially if you want to treat multiple similar parts.
The length of the working part should be chosen according to the following considerations: the nichrome should be heated to a dark red color when the current is connected. With a lower degree of heating wood and plywood will be sawed with difficulty, especially if the woodcarving sketches sculptures board has a large thickness. If the temperature is higher, the wood fumes can ignite. Practically, instead of sawing woodcarving sketches platbands in this case comes burning.
The design of the tool can be of 2 types: “rod” and “jigsaw”. In the first case, the tool consists of a wire of a certain length, to the ends of which are attached terminals from the secondary winding of the transformer, in addition to one end is attached to a wood carving omsk handle of non-conducting material and temperature (preferably wood), to the second. the weight, the size and weight which allows to keep the working part in tension. You can attach a handle to the second end of the working part instead of the weight.
The second option is a little more convenient for work and resembles an ordinary jigsaw ndash woodcarving sketches casings; nichrome is stretched on the jigsaw frame, but the clamps are made of a non-conductive material. The terminals in this case are attached to the wire BEFORE the clamps. The figure below shows how you can stretch the nichrome on the jigsaw frame with a special clamping bar. Terminals are attached after pulling woodcarving sketches drawings. It is not necessary to bring the working part to the state of “ringing string” as it is usually done with a saw. It is better to use a flexible frame, because the length of the working section of the nichrome, possibly woodcarving sketches hunters will have to adjust.
The length of the wire in both cases is depending on the power of the transformer used. If you need 100 mm length for 6 volt, you need a longer piece for higher voltages. Nichrome carving birds wood is used as other material with a small wire diameter will not withstand the desired heat.
Nichrome is usually taken with a diameter of 0.3 to 1 mm (the diameter depends on the thickness of the material to be cut through).
Transformer can be used from 6 to 24V, the source of the transformer can be an old TV, a filmoscope or other equipment.
A narrow nichrome wire connected to a step-down transformer can be used as a candidate for an ordinary hand jigsaw. Thus, the length is selected by experimenting on a particular transformer. For the convenience of adjusting the length of the working part or restoring it after a break, it is desirable not to cut off a piece of the desired length at once, but simply put a few turns on one of the contacts, which can be used as bolts and nuts.
Additionally, you need a wood carving owl switch on the wire coming from the transformer. to interrupt the current in the circuit when you transfer the wire from one wood carving sketches on paper to another and when the wire breaks (burns out).
Movement when woodburning should be the same as when sawing with a jigsaw. up and down, but very light, because the cutting speed of the flaming wire is much higher than when sawing.
Woodcarving with their own hands for beginners may present some difficulties. However, after a little theoretical training, selection of appropriate tools, and at least minimal practice, the problems usually disappear forever. After all, wood is a fairly easy material to work with, so almost everyone can cope with it.
In our article we will talk about how woodworking is performed for different purposes and what devices are used in this.
Basic principles of operation
The movements when burning should be of the same type as when sawing with a jigsaw. up and down, but very light, because the cutting speed of the glowing wire is much higher than when sawing.
A sample of the product obtained with this method.
You can also use the same method to cut glass, Styrofoam, plastic and other materials.
Sawing products from plywood is a very painstaking and accurate process that requires patience and attention. As an alternative to a hand jigsaw, you can use a nichrome wire connected to a step-down 24v, 12v, etc. transformer.д.
Read also: What wood is used to make rubber
This process is not even called sawing because heated wire will cut plywood or wood, not sawing.
The wire holder for the wire is best made the same as for a standard jigsaw. The only thing is that the wire should not come into contact with the metal jigsaw itself. It is recommended to make the wire clamps from a non-conductive material. And so that the material itself does not melt from the heated wire.
Using the same principle we cut the foam at home using the same transformer and nichrome wire
The alternative to the jigsaw
For those who do not have the ability or desire to use regular wood to create kerf (propyl) carving in wood and use plywood as a material, sawing with a jigsaw is not always the best way to work. Plywood is quite brittle and easy to break off. And it is often sawn with the formation of untidy tufts of fibers at the edges of the kerf. Besides, for wood the jigsaw is not always the best tool, especially if you have to cut several identical pieces.
As an alternative to the usual hand jigsaw, you can use a thin nichrome wire connected to a step-down transformer. In fact, instead of sawing in this case we get burning.
Using a gas torch
If you use a gas torch, you need to find a good ventilator to ventilate the room. To reduce the amount of smoke produced by soldering, it is important not only to run ventilation, but also to open all windows. When soldering, you need to direct the strong jets as far away from the work site as possible.
Before using a gas torch, you must prepare a container of water. The part to be treated must be fully seated in it. When brazing jewelry in this way, it is better to use a flat tip, because pointed models waste too much heat.
The process of joining metal inserts consists of the following steps:
Place the pieces on a non-flammable surface and fix them as closely as possible to one another. For the best realization of such a task, it is recommended to use nichrome wire and clamps.
A gas burner for soldering silver is sold in every specialty store or hypermarket. Thus everyone can learn how to solder with such a device properly.
The first thing you need to find a step-down transformer 60-100 Watts, the output of the transformer will be safe for humans AC voltage 12 volts at a sufficient to heat the filament current 5-10A.
The following parts will be needed for assembling:
The selection of the length of nichrome thread is carried out as follows: cut off and pick up a piece of nichrome wire so that it heats up to red (thread A), then connect to the same thread in series another piece of nichrome wire (thread B) and pick up its length so that the thread A heats up half or up to the desired value.
Let’s assume that the working length of thread for cutting is 13 cm, the rest of the thread A is twisted into a spiral, as well as the entire thread B is twisted into a spiral.
We fasten the twisted spirals in a convenient place of the cutter so that they do not interfere, and the cutting is done only with a stretched piece of thread 13cm long.
Machine with nichrome string for cutting foam plastic with their own hands
People’s craftsmen, inventors and innovators have never been translated in our country. Many of these enthusiastic people would like to know where to sell nichrome wire, where to get this material at home? How is it attractive to modern geeks and homebrew dodgers?? Nichrome wire is used to make torches, jigsaws, soldering irons, styrofoam and polystyrene cutting machines, etc.д. The material is also widely used in industrial production.