Wire cutting machines use current to cut durable metals and alloys - titanium, graphite, hardened and alloy steel. In addition, they can perform grinding, cutting, finishing, copying, and cutting out small and thick-walled parts, such as injection pins or medical needles. It is used for structural strengthening, in which a dense metal layer is formed inside, increasing strength.

How does it work?

Electric current is supplied from the generator to the workpiece and the electrode. The workpiece serves as a positive electrode - anode, and a molybdenum wire 0.18 mm thick serves as a negative cathode.

Under the influence of pulsed discharges, the metal is cut, melted and evaporated, forming thin sections. The space in which the spark action occurs is washed with a coolant that carries away particles of the destroyed material.

Equipment advantages

The advantages of electric spark machines include:

• Economical - the wire is used for several cutting sessions, so its consumption is minimal.
• They are compact, ergonomic and have low energy consumption. Therefore, they can be bought for a small workshop.
• The use of electroerosive machines reduces the amount of waste generated during metalworking; the operator’s workplace will always be clean. This feature is important primarily when working with expensive metals and alloys.
• CNC models are convenient, they can work after setting up to 140 hours without operator intervention. Reconfiguring the equipment takes only 15-20 minutes.
• By adjusting the parameters of the electric current and the position of the wire, you can create products of different shapes, processing the workpiece in several directions at once.
• The resulting products have a smooth and even mirror-like surface that does not require finishing, which reduces production time.
• Spark equipment is used in the production of products of complex shapes that are difficult to sharpen and mill.

Advantages of KMT

KMT offers to buy wire-cutting EDM machines from global brands that have proven themselves in metalworking in the European Union, Asia and America. The price is lower than similar European, South Korean or Japanese models.

All products comply with ISO and TUV standards for such equipment.

The company's managers will help organize delivery from a warehouse in Moscow to any region of Russia, installation and commissioning, production of a trial part, selection of components and personnel training. Warranty and post-warranty service is provided.

Electrical discharge machines CUT P from AgieCharmilles were announced in April 2017. This flagship series has no equal on the market in its capabilities and number of unique technical solutions.
The combination of the IPG-DPS digital generator with the Quadrax mechanical design, together with additional automation modules, has once again raised the bar for wire EDM machines to new heights.
This series includes four models with strokes along the X-axis from 350 mm to 1250 mm, while the weight of the workpiece is practically unlimited.
Quadrax designs are capable of angular machining up to 45˚ over the entire height of the workpiece. No other line of wire-cutting machines in the world has such capabilities.
The use of a new version of the IPG-DPS generator made it possible to increase the processing speed by 15-20%, while the accuracy of manufacturing small contour elements increased significantly. The surface roughness has also improved.
The thermal stabilization system, which maintains the temperature of the dielectric, the machine bed and all axes within a given range, guarantees high precision characteristics even when working in non-temperature-controlled rooms.
The optical measuring system OMS facilitates the binding of the workpiece, finding the center of the starting holes and controls the dimensions of the finished parts - this makes the operator’s work easier and saves working time.
A similar function is performed by the Renishaw probe, which is integrated into the design of the wire cutting machine. Its use is especially important in combination with a pallet changer - in automatic mode it will control the position of the workpiece, including the inclination of the upper surface, and make the necessary corrections to the program.
Also, AWS and AMS modules are aimed at increasing the efficiency of the wire-cutting EDM machine in offline mode. Which fix and automatically remove falling parts of the workpiece.
When looking at the Progress VP wire-cutting EDM machine, the words about “imperishable classics” come to mind - outwardly, these wire-cutting machines remain unchanged for 20 years. This impression is deceptive - the element base of the generator has changed several times, new modules have appeared, and the control system has been completely rewritten.
The level of technical solutions used in the design of the machines commands respect. A commensurate level of thermal stability, which Progress VP demonstrates during operation, is achieved by modern EDM machines through additional radiators, cooling circuits and tracking sensors. Here everything is decided due to the cabinet-type design and carefully thought-out placement of heat-generating elements.
A whole bunch of unique possibilities are provided by the use of patented prismatic wire guides:

• service life - 100 thousand hours
• ability to work with wire diameters ranging from 0.05 mm to 0.33 mm
• use of wire of different diameters and/or types in one program.

A wire cutter and a 25 kg reel as standard, together with the LOTO and AVTORESTART generator modules, are capable of ensuring autonomous operation of the machine for 85 hours.

Features and Specifications		Stroke dimensions X, Y, Z	Price in rubles: on request	Availability of equipment
AC Progress VP2	750 x 550 x 250 mm	350 x 250 x 256 mm		To order
AC Progress VP3	1050 x 650 x 420 mm	500 x 350 x 426 mm		To order
AC Progress VP4	1300 x 1000 x 510 mm	800 x 550 x 525 mm		To order
CUT P 350	1000 x 550 x 220 mm	350 x 220 x 220 mm		To order
CUT P 550	1200 x 700 x 400 mm	550 x 350 x 400 mm		To order
CUT P 800	1300 x 1000 x 510 mm	800 x 550 x 510 mm		To order
CUT 200 Dedicated	Ø150…Ø500 mm	350 x 220 x 220 mm		To order

Ultra Precision Wire Cutting Machines

CNC electroerosive machines from the Swiss company AgieCharmilles are designed for the automatic production of precision parts in the instrument-making, watchmaking, and medical industries. This involves the operation of a wire-cutting machine as part of robotic lines 24/7 and everything necessary for this is provided in the design of the machines.
The design of these wire-cut EDM machines, in addition to the technical solutions implemented in Progress VP, is based on a number of unique features:
The IWC module adds a second wire path and an automatic changer. You can choose or use wire different types in one processing program, or two 25 kg coils will allow the machine to operate autonomously for more than 170 hours.
The scope of application imposes additional requirements on the accuracy of the processed parts. The integrated optical measuring system IVU is responsible for the result of 1 µm. In addition to controlling dimensions and binding cycles, she is given the right to make changes to the control program so that the profile of the resulting parts is as close as possible to the specified one.
Electroerosive wire cutting machines AgieCharmilles OilTEch series use not traditional water as a working medium, but a hydrocarbon dielectric, as in piercing machines. This decision is dictated by the area of ​​application for which they are designed. The use of hydrocarbons provides both undeniable advantages and imposes certain restrictions on wire-cut technologies.
There are three main groups of tasks in which machines of this type are unrivaled:

• processing of highly corrosive materials;
• the surface roughness requirement is higher than Ra 0.05 µm;
• production of carbide tools;

If everything is more or less clear with the first two points, then the last point requires decoding.
Manufacturers of wire-cutting EDM machines are silent about the fact that when processing a hard alloy in an aqueous dielectric, the cobalt binder is washed out. Progress in this area is significant, but the durability of a carbide tool processed on a traditional wire-cut machine is lower than the durability of the same tool processed, for example, by grinding.
The use of a hydrocarbon (oil) dielectric solves this problem and the durability of a tool processed on a wire-cutting machine is not inferior to a tool produced using other technologies. In this case, the surface roughness reaches Ra 0.3 µm.

Features and Specifications	Workpiece dimensions (L x D x H)	Stroke dimensions X, Y, Z	Price in rubles: on request	Availability of equipment
CUT 1000	300 x 200 x 80 mm	220 x 160 x 100 mm		To order
CUT 1000 OilTech	300 x 200 x 80 mm	220 x 160 x 100 mm		To order
CUT 2000	750 x 550 x 250 mm	350 x 250 x 256 mm		To order
CUT 2000 OilTech	750 x 550 x 250 mm	350 x 250 x 256 mm		To order
CUT 3000	1050 x 650 x 250 mm	500 x 350 x 256 mm		To order

On video: AgieCharmilles CUT 2000 X, CUT 3000 X

Universal CNC wire cutting machines

CNC EDM machines CUT E introduced in 2016, the first family of AgieCharmilles wire cutting machines based on a new innovative platform. Main innovations:

• digital generator IPG-DPS;
• motor control controllers and industrial computer from BECKHOFF;
• AC HMI 2 control system.

First of all, wire-cutting machines of this series are intended for use in tool production for the manufacture of stamps and molds. These machines have the largest working baths in their class, which expands their functionality. It is worth noting that in comparison with the previous series of wire-cutting EDM machines, the designers managed to reduce the dimensions. The front width of the machines in this series is 200-300 mm less than that of its main competitors. Much attention is paid to improving convenience and safety, as well as ease of use. It is impossible not to mention the legendary electromechanical collision protection, which was first used in the world on Charmilles erosion machines. When hitting an obstacle at a speed of up to 3000 mm/min, it protects machine elements and the workpiece from damage and/or shifting, and also saves: time since it does not require re-binding the workpiece and money for the purchase of new nozzles or wire guides. The control system has also improved. AC HMI 2 has received new functionality while maintaining ease of use, and the vertical screen offers more space for additional information.

In the field of metalworking, the method of electrical discharge machining (EDM) has become widespread. The electroerosive processing method was discovered by Soviet scientists in 1947.

This technology could significantly facilitate the process of metal processing, especially in the processing of high-strength metals, in the manufacture of parts of complex structures, as well as in other areas.

The method is based on the effect of electric discharges in a dielectric medium on the part, resulting in the destruction of the metal or a change in its physical properties.

Application of the EEE method:

• When processing parts made of metals with complex physical and chemical properties;
• In the manufacture of parts with complex geometric parameters, with difficult machining;
• When alloying the surface to increase wear resistance and give parts the required qualities;
• Improving the characteristics of the top layer of the metal surface (hardening) due to oxidation of the material under the influence of an electric discharge;
• Marking of products without harmful influence, which is present in mechanical branding.

Different types of electrical discharge machining are used to perform different operations. Numerical control (CNC) devices are installed on industrial machines, which greatly simplifies the use of any type of processing.

Types of electrical discharge processing of material:

• Electric spark processing is used for cutting carbide materials, shaped cutting and for making holes in high-strength metals. Gives high accuracy, but the speed is low. Used in piercing machines.
• The electric contact processing method is based on local melting of metal by arc discharges with subsequent removal of waste material. The method has lower accuracy, but higher operating speed than the electric spark method. It is used when working with large parts made of cast iron, alloy steel, refractory and other metals.
• The electric pulse method is similar to the electric spark method, but arc discharges lasting up to 0.01 seconds are used. This gives high productivity with relatively good quality.
• The anodic-mechanical method is based on a combination of electrical and mechanical effects on the metal. The working tool is a disk, and the working medium is liquid glass or a substance with similar characteristics. A certain voltage is applied to the workpiece and the disk; during the discharge, the metal melts, and the slurry is removed mechanically by the disk.

In industry, machines are used that operate based on the method of electrical discharge machining of metal. They are classified according to several parameters: operating principle, control, presence of CNC, etc.

Types of machines operating on the EEO principle:

• Wire Erosion Machine;
• Electroerosive wire cutting machine;
• Electroerosive piercing machine.

Due to its multi-functionality, the EEO machine is necessary on the farm, and sometimes it is not at all replaceable. Everyone would like to have such a device in their garage. Unfortunately, buying such a factory-assembled machine is very expensive and often not possible. There is a way out of this situation - to assemble it yourself.

Cutting and stitching machine

Contrary to preconceived notions about the complexity and impracticability of such a task, this is not the case. This is a completely feasible task for the average person, although everything is not so simple. The simplest type of machine is a cutting machine, designed for processing parts made of alloyed, refractory and other durable metals.

The electrical circuit contains: a power source, a diode bridge, a light bulb and a set of capacitors connected in a parallel circuit. The electrode and the workpiece are connected to the output. Let us note again that this circuit diagram for a figurative concept of the operating principle of the device. In practice, the diagram is supplemented with various elements that allow you to adjust the piercing machine to the required parameters.

General requirements for the electrical circuit of a cutting machine:

• Consider the required power of the machine when choosing a transformer;
• The voltage across the capacitor must be greater than 320 V;
• The total capacitance of the capacitors must be at least 1000 μF;
• The cable running from the circuit to the contacts must only be copper and have a cross-section of at least 10 mm;

One example of a working diagram:

As you can immediately see, the scheme differs significantly from the fundamental one, but at the same time it is not something supernatural. All details electrical diagram can be found in specialized stores or simply in old electronic devices, long gathering dust somewhere in the garage. An excellent solution is to use CNC to control the machine, but this method of control costs a lot, and connecting it to a homemade machine requires certain skills and knowledge.

Machine design

All elements of the electrical circuit must be securely fixed in a dielectric housing; it is advisable to use fluoroplastic or another with similar characteristics as the material. The necessary toggle switches, regulators and measuring instruments can be displayed on the panel.

On the frame you need to attach a holder for the electrode (must be movably fixed) and the workpiece, as well as a bath for the dielectric, in which the entire process will take place. As an addition, you can install automatic electrode supply, it will be very convenient. The operation of such a machine is very slow, and it takes a lot of time to make a deep hole.

DIY wire machine

The electrical circuit of a wire cutting machine is the same as that of a cutting machine, with the exception of some nuances. Let's look at other differences of the wire machine. Structurally, a wire cutting machine is also similar to a cutting machine, but there is a difference - it is a working element of the machine. On a wire loom, as opposed to a cutting machine, there is thin copper wire on two drums, and during operation the wire is rewound from one drum to another.

This was done to reduce wear on the working tool. A fixed wire will quickly become unusable. This complicates the design with a wire movement mechanism, which must be installed on the frame for convenient processing of parts. At the same time, it gives the machine additional functionality. When cutting out complex elements, the best option would be to use CNC, but, as mentioned above, this is due to some difficulties.

• Electroerosive wire-cutting machines with CNC Balt-System (Russia) jet type DK77-MS series
• Electroerosive wire-cutting machines of jet type DK77 series available in warehouse in Moscow
• Electroerosive copying and piercing machines ZNC with a controlled Z axis, D71 series, available in warehouse in Moscow
• Electroerosive wire cutting machines ACCUTEX, Taiwan
• Electroerosive wire-cutting machines of submersible type (CW series) Aristech, Taiwan
• Electroerosive wire-cutting machines of submersible type with automatic wire filling (СW-S series) Aristech, Taiwan
• EDM copying and broaching machine (LS series) Aristech, Taiwan
• CNC electroerosive piercing machines (CNC series) Aristech, Taiwan
• Electroerosive Super Drills
• EDM copying and broaching machines with CNC lifting bath MAXSEE, Taiwan
• Precision copying and broaching machines NEU-AR
• Electroerosive extractor. Removal of drills and taps from NPP "MEATEC". Available in warehouse in Moscow.

Electroerosive wire-cutting machines of jet type DK77 series available in warehouse in Moscow

Price: from $11,500 including VAT

Installation of servo drives on a DK77 series machine.

Wire EDM machines are designed for the production of parts of various shapes and sizes, such as tools, machine parts, jewelry, stamps, processing of teeth, splines, etc. These machines allow you to process parts made of various grades of steel, high-strength composite alloys, titanium, graphite and much more. Models differ in the amount of movement along the axes, the dimensions of the work table, and the type of processing - “single-pass” or “multi-pass”. All machine models are designed for processing any conductive materials with high precision and excellent surface quality.

Application area:

When designing the machines of LLC NPP "MEATEK", processing accuracy, ease of operation, labor savings and long service life were taken as a basis, which undoubtedly affected the popularity of this equipment and its widespread use in enterprises of various levels. These machines are mainly used in the production of stamps and molds, because Accuracy is the main advantage of these models. With just one tool to get the job done, this machine is your affordable alternative to milling, turning and grinding equipment.

Processing scheme.

Advantages of our equipment:

• Processing of any conductive materials of any hardness.
• No chips (metal melts and evaporates).
• No thermal or mechanical influence on the structure (the surface is not deformed).
• The minimum cutting thickness of 0.2 mm allows you to effectively save the processed material.
• The ability to obtain parts of complex shapes and very small sizes, the production of which is difficult by other methods.
• Processing of holes of small diameters and roundings of small internal and external radii.
• Possibility of batch processing.
• Due to the low cost of the processing process and eliminating the problems of manufacturing expensive punching dies, the machine is the best replacement for stamping production.
• Possibility of short-term payback of equipment in the presence of problematic parts due to the overall low cost of processing, quick changeover of equipmentfrom one product to another.
• The simplicity of the machine design increases its reliability.
• The presence of a wire drum, which rotates in different directions and at different speeds, thereby ensuring rough and finishing cuts.
• Repeated use of a wire electrode reduces the cost of the processing process.
• Rational use of consumables.
• Simplicity and clarity of creating complex contours and surfaces using the popular CAM/CAD programs Compass and AutoCAD.

Made in Russia LLC NPP "MEATEK".

Jet-type wire-cut electroerosive machines of the DK77 series operate on molybdenum wire. Unlike wire electroerosive machines of submersible type SV series, jet-type machines of the DK77 series are equipped with an open work table on which the workpiece is placed for processing without immersing it directly in the working fluid.

Coolant fluid is supplied to the molybdenum wire through a nozzle, directly into the zone electrical discharge machining, which leads to cooling in the area electrical discharge cutting and leaching of erosion products.

Parts and assemblies of modern machines and devices are distinguished by a wide variety of designs and materials used, including those whose shaping using known machining methods is difficult and sometimes impossible. Associated with this is the increasingly widespread use of electrical discharge machining processes. “The possibilities of EDM machines are endless!” - this phrase can often be heard from users of machine tools just a month after putting the equipment into operation.

Classification
According to their technological purpose, machines for electrical discharge (ED) machining are divided into two main types - copy-piercing and wire-cutting.
Copying and broaching machines allow processing of shaped holes and cavities, internal and external surfaces of rotating bodies, grinding and cutting. It is possible to obtain helical and involute surfaces, as well as various internal shaped holes and cavities with direct, reverse and variable cones. In copying and piercing machines, the electrode-tool is shaped, its shape is an inverse copy of the cavity that is to be processed.
EE wire-cutting machines are used for the production of parts for stamps, copiers, templates, shaped cutters, patterns and other tooling. The electrode tool in cutting machines is a continuously rewound wire. The design features of the machines determine their technological advantages: no shaped tool is required, there is no need to make adjustments for electrode wear, it is possible to produce small parts of complex shapes, including parts with an equidistant profile (dies, punches) using one CNC program.

Stages of progress
EE processing, both in the world and in our country, is no longer an unconventional processing method. Currently, EE equipment is the fourth most used in the world after milling, turning and grinding. Sales of EDM increased from 0.5% in 1960 to more than 6% of the MOO market in 2000.
Priority in the discovery of electrical erosion belongs to Russia. The first practical research in this area was done in the Urals at the end of the 30s by the spouses B. and N. Lazarenko when studying the problems of contact erosion. The discovery was registered in 1943. The world's first EE cutting machine was manufactured at a plant in Fryazino, Moscow Region, in 1954. But, unfortunately, the production of EE equipment in the Soviet Union did not receive proper development.

EE wire cutting
EE cutting on wire cutting machines appeared in the early seventies and is continuously progressing in several directions.
Cutting speed increased from approximately 10 mm 2 /min. in the early seventies up to 35 mm 2 /min. in the mid-eighties, and has now reached 330-360 mm 2 /min. The increase in speed was achieved primarily through flushing the working surface with liquid under increased pressure and the use of more efficient pulse generators, which make it possible to set optimal parameters. The increase in speed is also facilitated by improving the quality of the electrodes.
To take advantage of high-speed cutting and eliminate machine downtime, reliable and efficient automatic wire threading devices, wire break prevention devices, and automatic part loading devices have been developed.
Maximum height matrixes and punches of stamps, processed initially on erosion machines, ranged from 50 to 100 mm. However, to process molds, extrusion dies and other various parts, manufacturers of EDM machines have expanded the range of sizes of parts processed on them.
Initially tapered hole angle, equal to 1° for parts with a height of 100 to 125 mm, was practically the maximum possible. To meet the requirements of consumers, currently an angle of 30° with a workpiece height of about 400 mm can be achieved on most machine models.
Maximum achievable accuracy increased from 25 microns, which was typical for the first machines, to 1 micron for modern EE machines. Operators of modern notching machines require significantly less effort to achieve machining accuracy of about 1 micron compared to experienced operators of the first notching machines, which achieved machining accuracy of about 5 or 2.5 microns.
This simplification of work to ensure increased accuracy is due to the development of several factors. The technology “built-in” into the latest machines ensures that the required contour is cut in exact accordance with the geometric program. Optical rulers provide stable accuracy regardless of the duration of machine operation and significant temperature fluctuations.
The most important innovation is the equipment of the machines with highly reliable and efficient automatic wire threading devices, which allow the processing of a number of parts without operator intervention. The ease of use of the machines makes it possible to increase the cost of processing and service more machines in the shop with less effort, even during the day shift.

EE firmware
The most significant improvement in CNC copying and broaching machines compared to manually controlled machines has been the reduction in processing cycle time, and above all, the reduction in operator time. In 1960, processing a cavity with an electrode tool required approximately 4 hours of operator work and 4.5 hours of electrical erosion time. With the advent of CNC already in the mid-eighties, the required operator time was only 0.5 hours, and the erosion time was about three hours.
New stage of time reduction processing cycles began in 1999 by equipping copying and broaching machines with adaptive pulse generators. Compared to previously produced ones, these generators have the ability to optimize the processing process based on its continuous monitoring. Such a generator also adapts the current density during machining in roughing modes, which greatly contributes to increasing the productivity of machining with electrodes of any shape. When processing in finishing modes, the system provides process control in order to protect the quality and uniformity of the machined surface using a more advanced sensor for contamination of the interelectrode gap. All this increases productivity by 10 times compared to previous generators.
Enterprises are turning to robotic machine loading systems to increase their operating time. deserted mode, increasing productivity per machine and reducing tool change time. The robot is built into the machine, the CNC system provides direct control machine and robot. Other benefits of this system include adaptive control, a 50% reduction in electrode change time and a reduced production footprint.
New control systems provide opportunities easier programming, helping to reduce operator work time. A typical control system allows the operator to program offline on a personal computer and then download the program to the machine. This provides a reduction of approximately 25% in programming time and erosion time for most operators.
Processing accuracy on copying and broaching machines largely depends on the accuracy of the electrode. The advent of affordable, high-speed milling machines for processing graphite electrodes on the market has made it easier for businesses to efficiently process large quantities of precision electrodes.
The accuracy of the latest models of copying and broaching machines has also been improved. This applies in particular to micromachining. For example, when performing electrical discharge machining of square cavities with an area of ​​60 mm 2, using the latest pulse generators, a cavity profile with a corner radius of 0.025 mm is obtained, due to a 65% reduction in electrode wear in these corners. This allows the use of six times fewer electrodes.
With increases in processing speed, size and complexity of workpiece shapes, increased accuracy achieved, easier machine operation, unattended operation, user training, customer support and accessibility, EDM has gained a stronger position in toolmaking and is increasingly being used in mainstream manufacturing. .
Today, not a single enterprise can ignore the possibilities of electroerosion, which can solve many production problems.
Moving directly to the analysis of EE equipment, we will dwell on several fundamental issues that significantly determine the effectiveness of EE processing.

Linear drives
Feed drives of EE CNC machines are built according to the traditional scheme. More reliable and modern drives are made without a belt drive. In these drives, the power stepper motor is directly connected to the lead screw. The disadvantages of these drives are well known:

• a large number of intermediate elements from the energy source to the working body (PO);
• the enormous inertia of these elements, which is especially noticeable in large machines;
• presence of gaps in transmitting devices;
• friction of mating parts, which changes sharply when the system transitions from a state of rest to a state of movement;
• temperature and elastic deformations of almost all transmission links;
• wear of mating elements during operation and loss of original accuracy;
• errors in the lead screw pitch and accumulated length error, etc.

Since these shortcomings reduce the main qualitative characteristics of drives (accuracy and uniformity of movement of the working element, the amount of backlash during reverse, permissible accelerations and speeds of the RO), the design ideas of machine tool builders have long been trying to somehow reduce their influence. For example, instead of a lead screw with a nut, an expensive and complex ball screw connection is used to reduce friction; in order to eliminate gaps, special connection tension devices are introduced into the connection between the screw and the nut; Lead screws of highly precise machines are manufactured according to the standard class; screw pitch errors are reduced using compensators; To combat temperature deformations, sophisticated cooling systems are created. However, it is clear that the problems of drives with lead screws are fundamentally unsolvable due to their physical and technical nature.
The task was to radically replace standard drives of metalworking machines with some others. And this solution was the use of linear motors (LM). The operating principle of such an engine has a number of advantages: there are no intermediate elements between the energy source and the RO, energy is transferred through an air gap, nothing needs to be rotated, and it becomes possible to carry out the main task - the longitudinal movement of the RO. All elements of electrical automation, electric brake systems, protection systems, special shock-type equipment, etc. have been operating on this principle for decades. Vast experience in the use of electromagnetic systems has revealed their advantages: amazing simplicity of design and use, the possibility of almost instantaneous stopping and reversing, speed of operation, large forces generated, ease of setup.
Naturally, the prospects of the solution were immediately appreciated. There was only one thing missing - the ability to regulate the speed of the RO in the electromagnetic system. And without this, it was impossible to use an electromagnetic drive as a propulsion device for the RO machine.
Research in this direction was especially intensive in Japan, where a linear drive was first used as a propulsion device for high-speed trains. Attempts were also made to create linear drives for metalworking machines, but the first developed samples had significant drawbacks: they created strong magnetic fields, overheated, and most importantly, did not ensure uniform movement of the RO.
Only on the threshold of the new millennium, mass-produced machines (for now only electroerosive ones) began to be equipped with a new generation of DMs, characterized by uniform movement of machine carriages with ultra-high precision, a large range of speed control, enormous accelerations, instant reverse, ease of maintenance and adjustment, etc. In principle, the design LD hasn't changed much. The motor consists of two elements: a stationary flat stator and a flat rotor with an air gap between them. Both the stator and the rotor are made in the form of flat, easily dismantled blocks. The stator is attached to the stand (base) of the machine, and the rotor is attached to the working element. The rotor is elementary simple, it consists of a set of rectangular bars, which are strong permanent magnets. The latter are fixed on a thin plate of special mineral ceramics, the coefficient of thermal expansion of which is half that of granite, and its hardness is close to that of sapphire.

With or without bath
EE wire-cutting machines without a bath (cutting only in a jet) have been produced and operated for a long time. Machines without a bathtub are 15-25 thousand dollars cheaper than machines with a bathtub (plunge cutting). If the enterprise has a fairly large area of ​​electroerosive machines, some of the machines without a bath are a justified solution. If there is only one machine, it is worth thinking about what it should be like.
Machines without a bath (jet) significantly limit the technological capabilities:

• it is impossible (or extremely difficult) to cut out contours in parts such as a hollow pipe;
• it is impossible (or extremely difficult) to make contour cutting of multilayer slabs with voids between the layers and in parts with holes, “pockets”, etc.;
• inkjet machines are only suitable for cutting parts of simple stamps, but do not provide a stable environment for electric spark discharges for complex tasks;
• only during blasting, air cannot be completely displaced from the cavities, which leads to increased formation of abnormal discharges and, as a result, wire breaks, defects, and cutting instability;
• without a bath it is impossible to ensure temperature stability if the room temperature fluctuates significantly during the day; This is especially dangerous when cutting dies of multi-window sequential dies. In a stream of water, conical cutting with angles greater than 15° at large thicknesses is unstable.

Water or oil
Oil is a delicate and friendly medium for electrical discharge machining of metal. High resistivity allows the generation of ultra-small spark discharges. The electric spark gap when cutting in oil is much smaller than in water.
In EE wire cutting, the tool size is the diameter of the wire plus 2 gaps. Since an EE discharge in water requires a larger gap, the size of the EE tool in water is always larger. In other words, with the same wire diameter, the resulting cut in water is wider than in oil. In addition, water is an aggressive environment for metal, which creates known problems. And these problems are more serious the smaller the size of the elements of the cut out contour.
The main reason why EE machines use water is for speed. Modern EE wire-cutting machines allow cutting at speeds of up to 360 mm2/min. However, speed in micro-cutting is a secondary indicator.
Oil as an EE cutting medium is much more attractive than water. In addition to smaller gaps, the oil is completely free of electrolytic erosion and surface corrosion. The quality and durability of the tool surface after cutting in oil is significantly higher than after cutting in water. In oil, the cutting speed even with wire with a diameter of 0.025-0.03 mm is stable.
Oil is an indispensable medium for EDM cutting of precision tools and small parts.

Manufacturers
The field of play (that is, the EDM market) is large, and there are many players on this field, however, as the famous Dutch football player Marco Van Basten said, football is played by 22 people, and the Germans always win. Likewise in the production of electrical erosion equipment, there are many manufacturers, but there are two clear leaders: the Japanese company Sodick and the Swiss AGIE Charmilles Group, which includes the companies AGIE and Charmilles. AGIE Charmilles Group and Sodick account for more than 60% of global EDM equipment sales.
The Russian market also offers products from such foreign companies as Fanuc, Hitachy, Mitsubishi (Japan), Dekkel, Diter Hansen (Germany), CDM Rovella (Italy), Electronica (India), Maurgan, Joemars Machinery (Taiwan), JSC MSHAC ( Armenia)…

Experts' opinions

Michael Riedel, Head of Special Tools Department at SCOB (Germany): “Since PKD (polycrystalline diamond) as a material has a hardness similar to diamond, almost all traditional processing technologies are not applicable to it. As a method of processing products made from this material, only electrical erosion can be used.”

Rudolf Eggen, director of Kroeplin GmbH (Switzerland): “There are three possibilities for manufacturing contact arms for linear measuring instruments: casting, laser cutting and electrical discharge cutting. We chose electrical discharge cutting because casting, with an annual production volume of 6,000 pieces per model, is too expensive, and laser cutting does not achieve the required accuracy due to insufficient repeatability of the results. In addition, due to the short duration of preparatory and final operations and the high autonomy of processing during night shifts and on non-working days, electrical discharge cutting is more economical than other methods.”

Frank Haug, Managing Director of Frank Haug GmbH (Germany): “The possibilities for using electrical discharge machining are endless. Our expectations regarding its use and accuracy were greatly exceeded. Thanks to this technology, we can now produce many products within tight deadlines.”

Walter Gunther, owner of Ganter Werkzeug (Germany): “Thanks to the rational use of EDM cutting, we can accurately produce microtomes with their components from the best materials and meet the stringent market requirements that make our competitors nervous.”

Advantages of wire EE processing

New possibilities in the manufacture of parts

Various wire diameters and the high suitability of wire EE machines for processing internal forms make it possible to produce parts that are not possible with traditional processing methods:

• obtaining deep grooves;
• production of parts with minimal internal radii;
• production of stamping equipment with high precision without manual finishing.

Reduced processing time

Obtaining a finished part from a heat-treated workpiece without the use of intermediate operations, achieving the required surface roughness without the use of manual finishing, manufacturing parts from hard alloys, ease of fastening workpieces on a machine due to the absence of loads on the workpiece during processing - all these advantages can radically reduce production time and plant costs compared to traditional processing methods.
Savings are achieved through:

• saving material (whole waste, not chips);
• using one machine with one tool to produce a finished part;
• no need for intermediate operations for heat treatment of workpieces;
• the ability to manufacture thin-walled parts and parts from fragile materials without the use of complex and expensive equipment.

Reduced labor costs when operating the machine

EE machines are designed for autonomous operation, which allows one operator to simultaneously service several machines.

Reliability and high accuracy

Due to the absence of mechanical loads on the workpiece and the constant updating of the tool - the wire - the dimensions of the resulting part are not distorted. Each part manufactured according to the appropriate program can be repeated any number of times; changes in size or configuration can be made in a matter of seconds if necessary.

A little physics

The principle of electrical discharge machining is based on the destruction and removal of material by the thermal and mechanical action of a pulsed electric gas discharge directed at the processed area of ​​the workpiece located in a liquid. In this case, complex physical and chemical processes occur in the discharge channel, in the workpiece, in the working fluid and in the electrode-tool, which determine the technological characteristics of the shaping process.
When the electrode-tool and the workpiece, immersed in a working fluid (dielectric or weak electrolyte), approach each other, discharges are initiated between them under the action of a pulsed generator voltage. The formation of discharges depends on the processing mode. An electric discharge is a highly concentrated impulse of electrical energy in space and time, converted into heat between the tool electrode and the workpiece electrode. After breakdown, a discharge channel is formed, surrounded by a gas bubble, both of which expand as the discharge progresses. When the surface of the electrodes is bombarded with electrons and ions from the discharge, a concentrated heat release occurs, causing the appearance of holes with molten metal, some of which is overheated and can evaporate. A significant part of the metal is removed at the end of the current pulse due to a sharp decrease in pressure in the discharge channel, accompanied by mechanical shock effects. Thus, electrical erosion of the conductive material occurs.
The materials from which the electrode tool is made must have high erosion resistance. The best indicators in this sense are copper, brass, tungsten, aluminum, and graphite. Working fluids must satisfy a number of requirements: low corrosiveness to the materials of the electrode-tool and the workpiece, heat flash and low volatility, good filterability, odorless and low toxicity.