Instructions for making a homemade laser. What you need to know about gas cutters for metal: portable and conventional, about the device and setup How to make a laser cutter with your own hands

Step 4: Laser Optics

Cutting a sheet of metal requires a laser beam with a heat flux density 1550 W/mm2.

A 100 W laser can achieve this flux density at spot sizes 0.6452 mm2 (280 microns). However, with the optics used in the project, the beam diameter ranged from 1.6 to 2.3 mm. In the case of 1.6 mm, with a threefold increase in the beam, we obtain a diameter 4.8mm.

Diameter calculation = 0.013 * M 2 * (focal length/D), where M 2 is equal to 1 and D is the diameter of the input beam.

If we replace M 2 with 1.5, we get a diameter of 150 µm. According to calculations, the density for this beam should be 1550 W/mm2.

Distance from laser (mm) = Beam diameter (mm)

• 0 mm = 1.9 mm;
• 250 mm = 2.9 mm;
• 500 mm = 4.7 mm;
• 750 mm = 6.7 mm;
• 1000 mm = 8.7 mm;
• 1500 mm = 12.9 mm;
• 2000 mm = 17.2 mm.

Thus, at a distance from the laser of 500 mm without any expansions, the beam diameter will be (assume M 2 = 1.5) = 0.013 * 1.5 * (38.1/4.7) = 0.158 mm

Step 6: Frequently Asked Questions

I want to make a cutting system. What would you do differently? Are there ways to save time when buying accessories?

Most of the mechanical parts like CNC table, cooling system, frame, laser are quite cheap. The buying process does not take long. Possibly the biggest technical challenge I have faced is the use of welding machine which may not be for everyone.

The optics were pretty much homemade and I don't think they will last long. There are some types of optics that are specifically designed for the laser. This will allow you to simply take the optic out of the box, connect it to the system and start cutting.

Electronics. You must have motors, several controllers, limit switches and an emergency switch. Putting it all together into one integrated system was a lot of work.

There are examples on ebay of laser cutters with enough power to cut metal. They are very expensive, require ventilation and cooling. A great option for those who have money.

Short answer to the question: if you do not have $50,000 to spare, then I think most of the elements of the system should be done by yourself.

Can I cut brass?

No you can't. The problem is that in copper and brass, heat spreads quite quickly. Because of this, it will not be possible to concentrate the heat flow at a certain point. The metal will not evaporate.

How much will it all cost?

At a rough estimate ... the total cost was about 15 thousand. $. The cost of the laser was about $6,500, the CNC table was $500, and the optics was $2,500. Cooling system - $500. There were many other unforeseen expenses such as: electronic components, motors, controllers, wiring for 220V and ventilation. It took 2 years to build the laser.

Looking at all these machines, I came up with the idea to remake my 3D CNC printer.

I don't think this will work. The problem is with lateral traction.

While the printer is running, put your hand in the path of the print head. You will see that even a small amount of resistance will hinder the work. Now consider installing an engraver instead of a print head.

Imagine the problems that will arise when a cutting tool works with inertia. If heavy cutting tool moves in one direction, then it will not be possible to quickly change the direction of movement. Attempts to make an emergency change of direction may damage the belts, gears or steppers. Most of these systems suffer from the fact that there are inaccuracies in the movement of the mechanism. The system has a backlash.

Can a laser cut? Does it leave burns?

No, he can not. One of the reasons a laser can't do this is because it uses CO2. The beam cannot penetrate the water, which is part of the skin. Another reason is that the beam power dissipates quickly. As an equivalent example, shooting a shotgun at targets at a distance of a kilometer. If you manage to get a cut, then the blood in it will immediately bake.

Step 7: Gallery

Various items that were made with a laser.

Thank you for your patience! CNC you homemade!

Anyone can do a laser for cutting metal with their own hands today. And this fact cannot but rejoice, because the cutter is a unique device, with the help of which, without much difficulty, it is possible to cut metal of almost any thickness with high quality and precision.

Benefits of laser cutting

The demand for this method of processing materials is determined by several factors.

Cutting quality

The first and one of the most significant indicators is the high quality of products cut with a laser. Such parts have a smooth, even cut and are characterized by the absence of any flaws on the treated surface.

Universality of the method

The second important advantage of laser cutting is that with the help of this procedure it has become possible to process almost all types of products, regardless of the hardness of the alloy from which they are made, their thickness or shape. In addition, the laser method of cutting parts is not limited to cutting in a plane, that is, it is possible to cut and voluminous objects.

Ability to automate the process

The third advantage is the possibility of automating the process of cutting metal with a laser using computer equipment. This property saves not only time, but also cash in the manufacture of special casting molds necessary for the production of products. This improves the productivity of the plant.

Computer-controlled metal cutting produces better parts that do not require additional turning and grinding.

Note that all of the above qualities are inherent, to one degree or another, to all laser metal cutters, both industrial and home-made. The only difference between them lies in the power of these devices. So, hand-made lasers for metal cutting have less power compared to professional laser machines. They are great for cutting plywood and thin sheets of metal, but not able to cope with super-hard and thick metal products, as opposed to specialized equipment.

But, despite this, homemade cutters are more popular among craftsmen. And all because industrial installations are quite expensive, and not everyone can afford to buy such a laser at home. Besides, in household there is no need to use a heavy-duty metal cutter, the simplest do-it-yourself cutter is enough.

What materials and devices will be required to make a metal cutting laser?

It is possible to make a metal laser cutter yourself by enlisting the following tools and materials:

• laser pointer;
• the simplest flashlight with rechargeable batteries;
• an old writing computer drive (CD / DVD-ROM) equipped with a matrix with a laser (it is possible in a non-working state);
• soldering iron;
• Screwdriver Set.

It is worth preparing a place in advance to create a device. Working area it is necessary to free from foreign objects, provide yourself with a convenient location and good lighting.

After everything you need is prepared, you can proceed directly to the assembly of the laser metal cutter.

Step-by-step instructions for making a laser for cutting metal

The first step in the process of making a homemade cutter is taking apart the drive of an old computer laser burner. To do this, you must carefully disassemble the device and remove the device itself without damaging its integrity.

Then you need to remove the red diode, which burns the disc while writing information to it. This diode, in other words - a laser emitter, is placed on a special carriage equipped with large quantity fasteners. To remove the emitter, you need to solder all the fasteners with a soldering iron. It is important to perform all actions with the utmost care, since any damage to the diode can cause it to fail.

The next step in assembling a laser metal cutter involves installing the emitter in place of the LED that the pointer is equipped with. To do this, carefully disassemble the pointer into 2 parts, without damaging the connectors and holders. Then take out the LED and put the laser in its place. You can fix it, if necessary, with ordinary PVA glue.

This is followed by the manufacture of a housing for a homemade laser cutter. You can assemble the case for the laser using a flashlight and rechargeable batteries, aligning the lower part of an ordinary flashlight, in which the batteries are located, with top pointers (before assembling, it is necessary to remove the glass installed in it from the tip of the pointer), where the emitter is located.

In the course of making such a connection, it is important to correctly, observing the polarity, connect the diode to the battery charging.

After completing all the steps, the cutter will be ready to go! It is important to remember that the device, if the safety rules are violated, can be harmful to health! Be careful!

DIY laser cutter

What is the difference between finished products

The main reason why many prefer a homemade laser cutter is the low cost of this device. It is impossible not to note the fact that a home laser for cutting metal performs simple tasks no worse than a factory one.

This is due to the single principle of operation of any laser metal cutter, which is as follows:

Principle of operation laser cutting

• During the cutting procedure, the laser acts on the metal surface in such a way that an oxidizing agent is formed on it, which increases the energy absorption coefficient.
• Powerful radiation causes the material to heat up.
• A very high temperature is created at the point of contact of the laser beam with the metal, leading to the melting of the metal surface.

The difference in the operation of a factory-made and a home-made laser cutter lies in their power, and, accordingly, in the depth of the laser cutting into the metal surface. So, factory models are equipped with high-quality materials, which provides a sufficient indicator of deepening. Homemade cutters are able to cut only 1-3 cm.

The possibility of making something useful from unused or worn-out equipment attracts many home craftsmen. One such useful device is the laser cutter. Having at your disposal a similar apparatus (some even make it from an ordinary laser pointer), you can perform decoration products from various materials.

What materials and mechanisms will be required

To make a simple DIY laser cutter, you will need the following materials and technical devices:

• laser pointer;
• an ordinary flashlight equipped with rechargeable batteries;
• an old writable drive (CD / DVD-RW) equipped with a laser drive (it is not at all necessary that such a drive be in working condition);
• soldering iron;
• set of locksmith tools.

In this way, a simple laser cutting device can be made using materials that are easy to find in a home workshop or garage.

The manufacturing process of a simple laser cutter

The main working element of a home-made cutter of the proposed design is the laser element of a computer disk drive. It is necessary to choose a writing drive model because the laser in such devices has a higher power, which allows you to burn tracks on the surface of the disk installed in them. The design of the reader-type disk drive also contains a laser emitter, but its power, used only to illuminate the disk, is low.

The laser emitter, which is equipped with a writing drive, is placed on a special carriage that can move in two directions. To remove the emitter from the carriage, it is necessary to free it from a large number fasteners and detachable devices. They should be removed very carefully so as not to damage the laser element. In addition to the usual tools, to remove the red laser diode (and to equip the homemade laser cutter, you need it), you will need a soldering iron to carefully release the diode from the existing solder joints. Removing the emitter from seat, care must be taken not to subject it to strong mechanical stress, which can cause it to fail.

The emitter removed from the writing computer disk drive must be installed instead of the LED, which was originally equipped with a laser pointer. To perform this procedure, the laser pointer must be disassembled by dividing its body into two parts. At the top of them is an LED, which should be removed and replaced with a laser emitter from a writing computer drive. When fixing such an emitter in the body of the pointer, you can use glue (it is only important to ensure that the eye of the emitter is located exactly in the center of the hole intended for the beam to exit).

The voltage generated by the power sources in a laser pointer is not enough to ensure the efficiency of using a laser cutter, so it is not advisable to use them to equip such a device. For a simple laser cutter, rechargeable batteries used in a conventional electric flashlight are suitable. Thus, by combining the lower part of the flashlight, which houses its rechargeable batteries, with the upper part of the laser pointer, where the emitter from the writing computer drive is already located, you can get a fully functional laser cutter. When performing such a combination, it is very important to observe the polarity batteries, which will feed the emitter with electricity.

Before assembling a homemade hand-held laser cutter of the proposed design, it is necessary to remove the glass installed in it from the tip of the pointer, which will prevent the passage of the laser beam. In addition, it is necessary to once again check the correct connection of the emitter with the batteries, as well as how accurately its eye is located in relation to the exit hole of the pointer tip. After all structural elements are securely interconnected, you can start using the cutter.

Of course, with the help of such a low-power laser it will not be possible to cut a metal sheet, it is not suitable for woodworking either, but it is suitable for solving simple tasks related to cutting cardboard or thin polymer sheets.

According to the algorithm described above, it is possible to manufacture a more powerful laser cutter, somewhat improving the proposed design. In particular, such a device must be additionally equipped with such elements as:

• capacitors, the capacitance of which is 100 pF and 100 mF;
• resistors with parameters 2–5 ohms;
• collimator - a device that is used to collect light rays passing through it into a narrow beam;
• LED flashlight with steel body.

Capacitors and resistors in the design of such a laser cutter are necessary in order to create a driver through which power supply will come from the batteries to the laser emitter. If you do not use the driver and put the current on the emitter directly, the latter may immediately fail. Despite the higher power, such a laser machine for cutting plywood, thick plastic, and even more so metal, will not work either.

How to make a more powerful machine

Home craftsmen are often interested in more powerful laser machines that you can make yourself. It is quite possible to make a laser for cutting plywood with your own hands and even a laser cutter for metal, but for this you need to acquire the appropriate components. At the same time, it is better to immediately make your own laser machine, which will have decent functionality and work in automatic mode, controlled by an external computer.

Depending on whether you are interested in your own hands or you need an apparatus for working on wood and other materials, you should correctly select the main element of such equipment - a laser emitter, the power of which can be different. Naturally, do-it-yourself laser cutting of plywood is performed by a device of lower power, and a laser for cutting metal must be equipped with an emitter with a power of at least 60 watts.

To make a full-fledged laser machine, including for cutting metal with your own hands, you will need the following expendable materials and accessories:

1. a controller that will be responsible for communication between an external computer and the electronic components of the device itself, thereby providing control over its operation;
2. electronic board equipped with an information display;
3. laser (its power is selected depending on the materials for the processing of which the manufactured cutter will be used);
4. stepper motors that will be responsible for moving the desktop of the device in two directions (stepper motors from unused printers or DVD players can be used as such motors);
5. cooling device for the emitter;
6. a DC-DC regulator that will control the amount of voltage supplied to the emitter electronic board;
7. transistors and electronic boards for controlling the cutter stepping motors;
8. Limit switches;
9. pulleys for installing toothed belts and the belts themselves;
10. housing, the size of which allows you to place in it all the elements of the assembled structure;
11. ball bearings of various diameters;
12. bolts, nuts, screws, couplers and collars;
13. wooden planks, from which the working frame of the cutter will be made;
14. metal rods with a diameter of 10 mm, which will be used as guide elements;
15. a computer and a USB cable with which it will connect to the cutter controller;
16. set of locksmith tools.

If you plan to use a laser machine for do-it-yourself metal work, then its design must be reinforced to withstand the weight of the workpiece. sheet metal.

The presence of a computer and a controller in the design of such a device makes it possible to use it not only as a laser cutter, but also as an engraving machine. With the help of this equipment, the operation of which is controlled by a special computer program, it is possible to apply the most complex patterns and inscriptions on the surface of the workpiece with high accuracy and detail. The corresponding program can be found freely available on the Internet.

By its design, a laser machine that you can make yourself is a shuttle-type device. Its movable and guiding elements are responsible for moving the working head along the X and Y axes. The Z-axis is taken to be the depth to which the workpiece is cut. For the movement of the working head of the laser cutter of the presented design, as mentioned above, stepper motors are responsible, which are fixed on the fixed parts of the device frame and connected to the moving elements using toothed belts.

Sliding support Head with laser and heatsink Carriage assembly

Placement of the carriage on the racks

To obtain individual fragments of rolled metal, guillotine cutting is often used, but in everyday life for this purpose it is much more convenient to use a portable gas cutter that performs a cut of any complexity.

1 What are gas cutters, and what are they?

From a metal sheet, as well as from steel pipe(or other profile), you can easily separate any parts using a conventional hacksaw blade for a metal saw. Also, a relatively even cut can be achieved using an electric arc, however, more than one electrode will be spent. Therefore, it is most correct to have it on hand, and in everyday life the compact version is most convenient. What is this device? Let's take a closer look at what can be used to cut steel and most non-ferrous metals.

Even in the distant past, it was noticed that a narrowly directed cone of flame has an extremely high temperature and sufficient pressure to form a hole in the metal under its influence. Moreover, the main role in cutting is not played by combustible gas or liquid fuel, and oxygen. The device consists of a body, inside which are channels for oxygen and combustible gas (propane, butane, acetylene or hydrogen), as well as pipes for supplying them to the nozzle. In fact, these are two separate parts - a handle and a tip connected by a union nut. The channels passing inside the first part are connected at the beginning of the nozzle, in this place an ejector or injector (mixing unit) is installed, depending on the type of device.

The principle of operation is the following. In the barrel, as a rule, there is a mixing tube, where oxygen sucks in combustible gas. In non-injector models, substances enter the nozzle through separate tubes, where they mix through small nozzles inside the mouthpiece. Further, a strong jet of oxygen, escaping from the nozzle along one slot, creates a rarefied area in front of the nozzle, where combustible gas is supplied through another hole, forming a long narrow torch. Due to the significant pressure in the cone, the metal quickly reaches the combustion temperature, which must necessarily be below the melting temperature.

However, all this general information, thanks to which you can understand what any gas cutter is. We are primarily interested in portable models. For the most part, if there are oxygen cylinders and corresponding channels in the apparatus, they are represented by injector options. But today there are also such devices as a miniature autonomous cutting torch, some varieties of which may not exceed the palm of an adult in size. These devices have either a built-in chamber for gas injection, or are connected to a small collet cylinder with a capacity of up to 0.5 liters. Their ignition can be external, from a match, or their own, using a piezoelectric element.

2 portable portable torches with oxygen and propane tanks

Many had the opportunity to observe the work of gas welders who transport large and heavy cylinders with oxygen and combustible gas from place to place on a trolley. To get at least some mobility, a long hose is connected to such a cylinder through a reducer, the other end of which is attached to the end of the cutter handle. It is inconvenient and rather difficult to operate such a device, for the most part precisely because of the length of the hose.

Another thing is a small portable, injection-type gas cutter. It is convenient in that it can be moved from place to place by 1 person, even lifting it up if necessary. considerable height. The kit necessarily includes a gas welding torch or a cutter, short hoses (up to 5 meters), 2 cylinders - for oxygen for 5 liters and propane, the capacity of which can be 2, 3 or 5 liters.

For transportation, a container-type plastic suitcase, a waterproof fabric bag with metal inserts, or a metal basket can be used. These kits are commonly used by air conditioner and refrigerator repair technicians (for welding and cutting copper tubes), but it can also be used in everyday life. Propane cylinders can also be filled with other combustible gases, for example, butane, or MAF, that is, a mixture of methylacetylene and propadiene.

3 Push-in device - advantages and disadvantages

Even with the most serious approach to country farming, the need for gas welding and, especially, cutting occurs quite rarely. Therefore purchase professional equipment it seems inappropriate to many, but often the owners of summer cottages do not want to go to great expense. Many prefer cheap and, at first glance, very effective, among which the gas collet is the most popular.

It looks like a nozzle on a cylinder of the appropriate type, the capacity of which can be from 225 to 500 milliliters. Often, such a device is equipped with a wide socket, and then it performs the functions of a mini-burner to a greater extent than a metal cutter. However, taking into account the ability to regulate the intensity of the flame, it is possible to obtain both a torch of several tens of centimeters and a rather narrow cone.

In the first case, the tool becomes excellent remedy for warming pipes and car locks frozen in the winter cold, and the second option can help with soldering if there is solder. This mini-device also has disadvantages. The first thing that will seem inconvenient to many is the fairly rapid consumption of combustible gas, which, with a small capacity, can become a hindrance to work. As a rule, the average production rate declared by manufacturers is 225 grams of fuel per hour, which corresponds to one cylinder of the smallest size.

If there is a lot of work on metal, you will have to stock up on a fair amount of such cylinders or buy the largest possible containers. In addition, the absence of oxygen in the jet does not contribute to high pressure in the flame cone, which is easily extinguished by gusts of wind. However, the temperature in it can reach 1300 degrees.

4 Small torch, or torch in your pocket

A very interesting option for many, which is, in fact, a lighter with a gas cutter nozzle at the top. True, the tank of the device is much larger in size, and the efficiency of the flame cone is much higher. Many were holding rather expensive turbocharged piezo lighters in their hands, in which the fire does not go out under gusts of wind due to significant acceleration in the turbine nozzle and the formation of a torch in a special nozzle.

However, almost always long burning the top of this match substitute gets very hot and the plastic parts start to melt in most cases.

The mini-cutter works on the same principle, that is, after pressing the valve when starting to work on metal, the gas passes through a microscopic hole before entering the nozzle. Due to this, the jet is accelerated, which is then ignited by the same piezoelectric element and forms a narrow flame cone. Only, unlike a turbocharged lighter, the nozzle heats up slightly, and upper part the device in which the gas channel is located can be safely held in your hand. True, the gas supply in the chamber is exhausted rather quickly, but it can be filled from a conventional collet cylinder.

The disadvantages of this device include the fact that at a high temperature in the flame cone (1300 degrees), the length of the torch, as a rule, is insignificant. Here, as in the previous type of cutter discussed above, the absence of oxygen supply affects. Therefore, there is no rarefied area in front of the nozzle, and the pressure of the cone remains insignificant, and therefore insufficient for working with steel. Such pocket mini-burners are most often used to ignite coal in a brazier in the country, they are also used by jewelers and the same masters who repair air conditioners with refrigerators.

5 Cutter instead of a soldering iron - melt tin and copper

If you take a standard cutter complete with oxygen and propane tanks, all that can be done with it is to cut a sheet of metal, or, conversely, to weld several steel parts. However, fine soldering is out of the question, as well as spot welding. small parts. However, today there are mini-cutters, with the help of which truly jewelry work on metal is performed.

In particular, especially miniature, more reminiscent of a massive fountain pen weighing no more than 60 grams. They are divided into 2 types: with a built-in reservoir and connected to a collet cylinder with a flexible short hose. At the same time, both options provide maximum freedom of movement for the hand holding the device. The first type, with a built-in gas chamber, gives more mobility if you have to move frequently during work, since there is no connection to the cylinder through a hose.

However, the advantage turns into a disadvantage if a large front of activity awaits you, since the supply of combustible gas in the tank is only designed for 15 minutes of continuous burning of the torch. In this regard, the constant connection of the mini-cutter to the cylinder is more convenient, especially if you take the largest collet capacity of 0.5 liters. However, if you need to move, the balloon will have to be moved from place to place.

A portable mini cutting torch usually has 2 modes for cutting metal. Through a standard nozzle, it produces a fairly wide cone of flame up to 4 centimeters long, and when a special nozzle is installed, a short, needle-shaped torch of high intensity is obtained. The first mode is convenient for melting tin and copper, as well as for soldering metal parts, and the second option is ideal for spot soldering small workpieces and for working with radio boards. The temperature in the flame cone, like other mini-cutters, reaches 1300 degrees, but at the same time, the device is not suitable for cutting steel due to lack of power. The consumption of such a gas soldering iron is only 12 grams per hour.

All photos from the article

Is it difficult to assemble a plywood laser cutting machine with your own hands? What problems can be expected at different stages of project implementation? What equipment will you need to buy? In the article we will try to find answers to these questions.

Pros and cons of laser cutting

When implementing any large-scale project there is always a question of its expediency. We will try to help the reader to give an independent answer to it.

Benefits

• The device for laser cutting plywood in practice is able to work not only with it. The list of processed materials includes leather, fabrics, plexiglass, plastics, in a word, all materials that have low thermal conductivity and a relatively low combustion temperature;
• Thanks to the CNC, the machine will allow you to cut with highest precision , creating detailed contours;
• Its possibilities are not limited to sharp. Laser cutting machines for plywood are quite capable of performing the functions of an engraver. By varying the speed of the carriage and the power of the beam, they can create complex images with tone transitions;
• By focusing the beam, the width of the cut can be kept to a minimum- from 1/100 mm, which again has a positive effect on the accuracy of manufacturing parts or the detail of the image applied to the workpiece.

Problems

Of course, without them, too, will not do:

• The price of the purchased equipment will not be cheap. The most popular solution for inexpensive home-made engravers - a laser diode extracted from a DVD burner - is categorically not suitable for cutting plywood due to low power. The minimum laser power for cutting plywood is 20 watts; with any significant thickness of the material, it is better to increase it to 40 - 80;

Reference: CO2 laser tube of this power when ordered directly from Chinese manufacturers will cost the customer 15 - 20 thousand rubles at the current rate. The cost of a complex and expensive focusing system, DSP controller, stepper motor driver and carriages will be added to the cost of the laser.

• The life cycle of the tube is from 3 to 8 thousand hours, after which it needs to be replaced;
• The laser requires liquid cooling. In industrial conditions, for this purpose, cooling plant working on the principle heat pump- chiller. The minimum cost of such a unit is 35 - 45 thousand rubles;

However: with a short duration of work, you can get by with a tank with a capacity of 80 - 100 liters and a water pump that will pump its contents through the tube jacket.

• CNC implies the presence of not only special software, but also sketches of the contour of the manufactured product. Drawings for laser cutting plywood are not so easy to find; their independent construction will take a very long time;
• Finally, the cutting of the material is carried out due to its rapid heating and evaporation. In this case, the edges of the cut are inevitably charred, and the room is filled with smoke. If so, you will have to design a closed case with a transparent lid and an intensive forced ventilation system.

Design

So, how does a homemade plywood cutting laser work?

The base of the bed is an aluminum profiled pipe 40x60 in size, fastened furniture corner and self-tapping screws for metal. The case is assembled from inexpensive laminated chipboard - it does not experience significant loads during operation.

Please note: a 12-volt LED Strip Light. The backlight will allow you to visually control the cutting process.

Guides are fixed directly on the tubes of the frame, ensuring the movement of the carriages along the transverse axis.

A longitudinal pipe with another guide is screwed to the carriages - already under the carriage, which provides direct movement of the head.

And here is the laser head itself for cutting plywood. The foil is used to seal the connection of the tube with the fitting.