Milling processing. What is milling, and types of milling? There is a division according to the type of machine

Machining of flat surfaces, depending on their location relative to the surface of the machine table, is divided into horizontal, vertical and inclined. It can be produced with cylindrical and end mills, respectively, on horizontal or vertical milling machines.

When machining flat surfaces with cylindrical cutters Setting up the machine begins with installing the cutter on the mandrel. It is very important to correctly combine the direction of the helical line of the cutter tooth with the direction of rotation of the machine spindle. When determining this combination, one should take into account the direction of the axial component of the cutting force Px, which during processing should be directed towards the machine spindle (Fig. 6.30).

During processing, the workpiece is placed directly on the table or in a fixture. When installed on a table, the workpiece must be aligned in a horizontal or vertical position using marking marks or using control and measuring tools. The workpiece is secured only after it has been aligned.

The selection of spindle speed and feed is carried out using reference tables to determine milling modes. Setting the cutter to a given cutting depth is carried out along the machine dial, after the cutter touches the surface of the workpiece and takes it out of the working area.

Machining flat surfaces with end mills

Face mills have a number of advantages over cylindrical ones: more rigid mounting, smooth operation of a large number of simultaneously working teeth, as well as high cutting and feed speeds, especially for cutters equipped with carbide inserts. Therefore, in most cases, it is advisable to process flat surfaces with end mills.

When machining with end mills, the machining accuracy increases, and the roughness of the machined surface decreases with increasing cutting speed and decreasing feed. Setting the end mill to the depth of cut is carried out in the same way as when installing a cylindrical cutter.

Processing of grooves and ledges by milling

A ledge is a recess limited by two mutually perpendicular planes forming a step. The part may have one or more ledges.

A groove is a recess limited by flat or shaped surfaces on three sides (Fig. 6.31). Depending on the shape of the recess, grooves are rectangular (Fig. 6.31, a), T-shaped (Fig. 6.31, b), dovetail type (Fig. 6.31, c), V-shaped (Fig. 6.31, d, d) and shaped. Grooves of any shape can be through, open or closed.

Shoulders and slots can be machined with disc and end mills, and shoulder milling can be done with end mills. The method of processing ledges and grooves is selected depending on the requirements for the dimensional accuracy and geometric shape of the processed grooves and ledges, as well as the roughness of the machined surface.

Through and open, i.e., having an exit on one side, grooves are processed with disk groove cutters, which provide the most accurate processing. The width and shape of the cutter must correspond to the width and shape of the groove. Disc slot cutters have a cutting edge only on the cylindrical surface, and the side surfaces of the cutter have an undercut approximately to reduce friction. In this regard, when regrinding, the size of the cutter decreases, therefore, in order to avoid regrinding, the machining process is processed with such cutters , as a rule, the grooves are of small depth.

End mills can be used to machine shoulders and grooves on vertical and horizontal milling machines.

When setting up a machine for processing grooves and shoulders with disk and end mills, it is important to correctly position the tool relative to the workpiece being processed. This operation is carried out quite simply when using installations when processing a workpiece in a fixture. The position of the installation relative to the basic elements of the device is specified by size D (Fig. 6.32). Installation of a cutter is usually carried out using a feeler gauge - a metal plate with a fixed size (1.3 or 5 mm). To adjust the tool vertically (Fig. 6.32, a), the machine console is carefully moved upward until the probe enters the gap between the installation and the cutter teeth tightly and without rolling. Rapid and sudden lifting of the console is prohibited, as this can lead to crumbling of the cutter teeth when the unit hits it during a sharp lift or to damage to the feeler gauge. Adjusting the tool horizontally (Fig. 6.32, b, c) relative to its side surface is also carried out using a probe, but in this case the table moves in the transverse direction.

In the absence of settings, the machine can be set up using marking marks or proceed as follows: bring the cutter to the side surface of the workpiece until it touches, moving the machine table in the transverse direction, and set the cross-feed flywheel dial to zero; then move the table in the transverse direction so that the cutter extends beyond the workpiece being processed, and finally move the cutter in the transverse direction to the position required for processing.

T-slots and dovetail slots are machined in several steps. First, a rectangular groove is milled using a disk cutter (Fig. 6.33, a); then the side surfaces are processed with a T-shaped cutter (Fig. 6.33, b); then the chamfers are removed using an angular cutter (Fig. 6.33, c) and, finally, with a calibrated cutter, the specified size B of the groove is obtained (Fig. 6.33, d). Machining a dovetail groove is carried out in two passes: first, a rectangular groove is made with an end mill or disk cutter, and then the side surfaces of the groove are processed with a special end mill.

Organization of a workplace at the site of the milling machine

At the milling operator's workplace (Fig. 6.34) there is a milling machine 1 and a cabinet 8 with tools and accessories for the machine. Remote control 9 is used to call a foreman or mechanic (used only in factory production conditions, not available when using the machine in training workshops). To the right of the machine there is a container 7 (containers) for workpieces to be processed and processed parts. Wiping rags are stored in box 5, and waste shavings are placed in box b. Near the machine there is a wooden stand 4. The cabinet 3 houses fixtures, and the rack 2 contains mandrels for securing cutters.

When operating a milling machine, the following rules must be observed.

Before starting work you must:

Check the serviceability of the machine;

Check the serviceability of grounding and the presence of fencing of the work area;

Consistently check the performance of all machine mechanisms, cooling and lubrication systems;

Lubricate the machine components by filling the oilers to the specified level;

Study the technological documentation, as well as check the availability and serviceability of the relevant equipment;

Attach fixtures and cutting tools to the machine;

Set the spindle speed and minute feed according to the technological map;

Remove all foreign objects from the workplace;

Make sure the machine is set up correctly.

During work you must:

Strictly observe the setting of the machine to the specified mode;

Work only with serviceable and well-sharpened tools;

Place parts, tools and devices only in their place and use only for their intended purpose;

Make sure that cutting and measuring tools, keys, workpieces and processed parts are not on the working surfaces of the table;

Monitor the strength of the fastening of the workpieces, tools and devices being processed;

Single-spindle milling machines - horizontal, vertical and universal horizontal milling machines - are widely used in industry. In addition, specialized and special milling machines are available. Specialized milling machines include multi-spindle longitudinal milling machines with spindles located in different planes; face milling machines for processing planes, rotary milling machines with rotating tables; drum-milling machines with a rotating drum and copy-milling machines for processing shaped surfaces. Special machines include thread milling, key-milling, aggregate-milling and rack-and-pinion machines.

In single spindle horizontal milling on the machine the spindle is located horizontally; V vertical milling machine- vertically; Otherwise, the device of the machine is not fundamentally different from a horizontal milling machine. Vertical milling machines are equipped with both rectangular and round tables.

Universal milling machines differ from those described in that they have a rotary table, which allows milling operations for helical grooves (for example, in twist drills) and gears with helical teeth.

Longitudinal milling machine is typical for a group of specialized milling machines. Such machines are manufactured with one or more vertical and horizontal spindles; in the latter case, the workpiece can be processed simultaneously from several sides. In Fig. 175, and shows a general view of a four-spindle longitudinal milling machine. A table 2 can move along the guides of the frame 1, on which the workpieces are secured. Processing is carried out with cutters installed in spindles located in spindle heads 3, 5, 6 and 7. Since the table is stationary, in order to obtain the required dimensions during processing, the tool is installed by extending the spindles along their axis and moving spindle heads 5 and 6 along the crossbar guides 4 perpendicular to the axes of the spindles of these headstocks.

Drum milling machines belong to the group of continuously operating machines. They are predominantly used in large-scale and mass production. Such machines can simultaneously process two planes of workpieces. In Fig. 175, b shows a diagram of the machine. On a shaft 5 passing through the frame of the bed, a drum 3 is mounted, having the shape of a regular quadrangle (and sometimes a pentagon and hexagon), on the faces of which devices 6 are installed for securing the part. The shaft together with drum 3 rotates from a separate drive 4. The rotation speed of the drum can be adjusted by a feed box placed in the frame body.

On two stands 1 there are milling heads 2, which are independent units with individual drives. Milling heads can be moved on stands and fixed in any position according to the machine settings. To regulate the depth of milling, the spindles, in addition to rotational movement, have translational movement in the direction of the rotation axis. The productivity of the machine depends on the number of simultaneously processed workpieces and the rotation speed of the drum.

On milling machines, flat surfaces can be processed with cylindrical cutters when the machine table with a fixed workpiece moves towards the direction of movement of the teeth, i.e. by counter milling method(Fig. 176, a) or in the same direction down milling method(Fig. 176, b). In both cases, the chip removed by each cutter tooth is comma-shaped, but in the first case the thickness of the chip gradually increases during the cutting process, and in the second it decreases.

The advantage of counter milling is the gradual increase in load on the tooth and the cutting of the teeth into the metal under the crust. The disadvantage of this method is the tendency of the cutter to tear the workpiece off the table surface.

Milling accuracy depends on the type of machine, tool, cutting conditions and other factors. When milling, accuracy of 8...11 quality can be achieved, and for high-speed and fine milling - up to 7 quality. Surface roughness during finishing milling Ra=6.3…1.6 µm.

In Fig. 177 shows various types of processing on milling machines:α - processing of the plane with a cylindrical cutter; b - processing the plane with an end mill; c, d - processing of the vertical plane and groove with a three-sided disk cutter; d - processing of the groove with an end mill; e - processing of side planes with two end mills; g - processing of a complex profile with a set of cutters.

Milling machines. The main purpose of a milling machine (milling machine) is to produce flat and shaped (profile) planing of the edges of parts and mandrel (overtaking) around the perimeter of panels, frames, boxes.
The main parts of a milling machine: bed, work table, support, spindle shaft, insert spindle, cutting tool.
The support is located under the desktop; it carries the most important part of the machine - the spindle shaft. Through a hole in the table, the spindle shaft comes out with its upper end onto the working surface of the table. With a belt drive, its middle part serves as a working pulley. The support with the spindle shaft can be raised, lowered and secured in the required position with a locking screw. The spindle shaft is driven directly from the electric motor shaft or through a belt drive.
A working (plug-in) spindle is inserted into the upper end of the spindle shaft, onto which the cutting tool is mounted. The upper part of the insert spindle fits into a ball bearing mounted on a bracket. Thanks to this, the spindle and cutting tool do not experience vibrations at high locations or under heavy workloads.
When milling straight parts, a guide ruler is installed on the work table. It consists of two parts connected by a cast bracket that goes around the cutting tool. Parts of the ruler can be moved apart depending on the size of the cutting tool and installed perpendicular to the table either in one plane when the milling is profile or when it is not carried out over the entire thickness of the part, or in different planes, like the plates of a jointing machine, if the milling is flat planing.
Upper clamps for workpieces are often strengthened on the ruler. The ruler itself is secured with screws passing through the slots in the workbench. On the workbench for installation and fastening of stops there are two parallel longitudinal grooves of cross-section, in the shape of a dovetail. For through (full length) milling of parts, clamps are used. The upper clamps are usually attached to the guide ruler, the side clamps are installed on the work table.
The top and side clamps to the milling machine can be arranged so that they simultaneously serve as guards. Roller clamps must be considered the best, as they facilitate the feeding of the processed material. Combs and springs, on the contrary, make feeding somewhat difficult due to friction. Until now, most milling machines have manual feed. The machines of the latest design are equipped with automatic feed mechanisms.
Cutting tools for milling machines. On milling machines, chucks with flat knives inserted into them, milling heads, solid and composite cutters, double-cutting hook cutters, slotting discs, and saws are used as cutting tools.
Flat knives, single-sided and double-sided, have straight cutting edges for flat milling or curved ones for cutting simple and shallow profiles. The thickness of the knives is 8-10 mm. The knife is inserted into the slot of the working spindle and secured with an end bolt. Flat single-sided knives can be fastened in a chuck, which consists of two clamping washers with grooves into which the knives are inserted with their side edges. The washers are tightened on the spindle with a nut. Fastening flat single-sided knives in clamping washers is more reliable. The flight of the knives when the nut is loosened is prevented by pins in the grooves of the upper washer, which fit into the corresponding cutouts on the side edges of the knives.
Knives can be mounted in milling heads - knife shafts of reduced length, having a hole in the center for the working spindle. The milling head mounted on the spindle is tightened with a nut.
A solid cutter (cutter) is a multi-cutting tool made from one piece of steel. There are solid cylindrical cutters with straight and oblique teeth, slotted, grooved, shaped.
Solid cutters have a number of advantages: a) the presence of a significant number of cutters - for shaped cutters at least four, for cylindrical cutters up to ten; b) balancing of cutters during their manufacture; c) preservation of a constant profile by the cutters when sharpened correctly; d) relative safety in operation due to the absence of insert knives; e) quick installation on the spindle.
The diameter of solid cutters is from 80 to 120 mm. Composite cutters are assembled from several solid cutters, connecting them into a common milling head. Compound cutters are used for machining wide, deep or very complex profiles. Double-cutting hook cutters are designed primarily for producing tenons and eyes. They are designed for milling widths of 4, 6, 8, 10 and 12 mm. The diameter of the circle of rotation of the cutting edges is 140, 160 and 180 mm. Hook cutters made of steel plates 80 mm wide are widely used.
Slotted discs are used primarily for selecting lugs with a width of 8, 9, 10, 12, 14, 16 and 18 mm. Discs usually have three cutters, but discs with more cutters are now available. Disc diameters are 250, 300 and 350 mm.
The sharpening angle of inserted milling knives is 40°, the cutters of solid milling cutters are 50-60°; cutting angle 60-70°. On milling machines, small fine-toothed circular saws are also used as cutting tools.
The nut for securing the cutting tool to the spindle of the milling machine is tightened with a wrench until it stops. The use of any kind of levers and “linked” keys is not allowed. The spindle thread must protrude at least 1 mm above the nut.
For precise height adjustment of the cutting tool, lining rings are put on the spindle. If several instruments are installed at a certain distance from each other, then spacer rings are used.
Cylindrical cutters with fixed profile. The disadvantage of most cutting tools for milling machines is that after prolonged use and repeated sharpening, the radius decreases and the profile of the cutting edge changes. The knife or cutter becomes unusable.

WORK ON MILLING MACHINES

Milling straight edges. Straight edges are milled: a) to align them with a ruler; b) for selecting a profile along the entire length of the part (through milling); c) for selecting a profile for part of the length of the part (non-through milling).
In all three cases, milling is carried out along a guide ruler. When processing more or less long parts, wooden blocks are attached to the halves of the ruler. To align the edge of a part under the ruler, the output half of the ruler (the second from the machine operator) is installed in the same plane with the cutting edges of the cutters, and the front half is moved away or, as they say, recessed from the cutting line by the thickness of the chip. They often do it differently: they attach bars to the halves of the ruler, the difference in thickness being equal to the thickness of the chips. The work is carried out in the same way as on a jointing machine.
In the case of profile milling, when part of the width of the edge being processed is not milled, both halves of the guide ruler are installed in the same plane and then the cutting edges of the shaped knives or cutters protrude beyond the ruler to the milling depth. In this case, it is very convenient to attach one solid block to the ruler with a slot for the cutting part of the tool.
The work is carried out in the same way as when milling under a ruler. In non-through milling, the part in a position slightly inclined to the ruler is rested with its end against the stop in front of the cutters, then it is pressed against the guide ruler. In this position, the part is pushed onto the cutters to the opposite stop.
When straight-line milling, especially when milling narrow parts - posts, layouts, etc., it is imperative to use upper and side clamping devices. If there are no such devices, attach a planed block strictly parallel to the guide ruler at a distance from it equal to the width of the parts being processed, and between the block and the ruler the parts are pushed under the cutter. In most cases, a second bar is attached on top, which simultaneously serves as a clamp for the workpiece and a safety device that ensures safe operation.
Milling curved edges. Milling of external curved edges is carried out on a template using a thrust ring placed on the working spindle under the cutter. To reduce friction, a ball bearing is often used as a thrust ring.
A template for milling one curved edge of a part (for example, a bracket for a shelf) consists of a board 25-50 mm thick, the edge of which is processed according to the curvature of the part intended for processing. The template contains longitudinal and end stops and one or more clamps according to the dimensions of the part. The best clamps in terms of speed of action are eccentric ones. To prevent the eccentrics from leaving dents on the surface of the workpiece, wooden pads are suspended under them on springs. To protect against rapid wear, the working edge of the template and the working surface of the eccentric are often covered with tinplate. The workpiece, sawn on a band saw along curved edges with an allowance for milling, is laid and clamped on the template and, together with it, is fed to a rotating cutter. The edge of the template must be pressed against the thrust ring during the entire feeding time. The cutters of the cutter will process the edge of the part according to the curvature of the template edge.
The described method performs both smooth and profile processing. The milled edge can have any curvature, but with a radius of curvature not less than the radius of the thrust ring.
Mandrel (overtaking) along the perimeter of shields and frames is also done on a template using a thrust ring. The templates used are made in the form of precisely machined panels to size. The shield or frame is attached (pricked) to the template using pins. In this case, place a shield or frame on the machine table under the template. The thrust ring is placed over the cutter.
The shield or frame being processed is pricked on the inside, since there are still traces of the pricks. Less noticeable marks are left by flat, oval or rhombic tattoos, if they are correctly positioned relative to the fibers in the shield or frame; round and square tattoos leave more noticeable marks.
When working on milling machines, it is necessary to especially strictly observe safety rules, since the cutting tool cannot be completely protected, and milling is carried out at a high number of revolutions. The machine operator is obliged to ensure that the installation of the support is accurate and reliable, that the upper part of the spindle does not vibrate during operation and that the cutters do not hit, and that the guards for dangerous places are in good working order. He must check the fastening of the insert spindle, the installation and fastening of the cutting tool, and tighten the bolts and nuts. You can only work with a serviceable, balanced, well-sharpened cutting tool that does not have cracks, nicks, or burns.
Accessories for milling machines for mechanized feeding, machines with a feeding mechanism. The machine tool industry currently produces devices for mechanizing feed on milling machines of older designs; new milling machines are produced with a constant feed mechanism. The following devices are quite widely used.
An asterisk is put on the working spindle instead of a thrust ring, or the ring itself is made in the form of an asterisk. During operation of the machine, a sprocket or star ring from a special mechanism rotates with a small number of revolutions in the direction opposite to the rotation of the spindle. At the same time, it interacts with the template used for milling. In the working edge of the template, covered with sheet steel, nests are arranged, the size and location corresponding to the sprocket teeth and their pitch. The template, pressed against the thrust ring by the teeth of the sprocket, automatically moves towards the cutters of the rotating cutter.
The feed speed of the sprocket can be from 5 to 15 m/min depending on the type of wood, the depth and width of the milling, as well as the number of revolutions of the sprocket.
Double roller attachment: works in the same way as the feed rollers of other machines. Usually two pairs of rollers are used, placing them on both sides of the cutter.
A single-roll device with a horizontal roller position above the work table: in addition to feeding straight parts to the cutter, it presses the parts against the work table in addition to the upper clamping devices. Roller devices are used to feed straight parts; They operate from individual electric motors with a power of 0.5 kW. Feed speed up to 25 m/min. The surface of the rollers is covered with rubber. A caterpillar-conveyor device with spring stops is installed above the workpieces or on the side. Along with feeding, this device presses the parts against the table or guide line. It works from an individual electric motor.
Mechanical feed machines. The machine tool industry produces milling machines with mechanical feeding of workpieces using a rotary table. The FKA rotary milling single-spindle machine is equipped with a round work table rotating from an individual electric motor.
The table is equipped with pneumatic clamps. The machine can process one or more parts of different shapes. Templates with parts are fixed on the machine table along its circumference. The spindle, under the action of a load suspended through the block or by the force of a spring, is pressed by a thrust ring against the working edge of the template. As soon as the thrust ring comes into contact with the template, the table rotation motor automatically turns on and processing of the part begins; With the ring removed, the electric motor is automatically switched off.
The table rotation speed can be reduced during part processing. This is used when milling corners to prevent chipping. The spindle makes 6000 rpm, the power of its electric motor is 4.2 kW; table rotation electric motor power 1.2 kW. Table diameter 1000 mm.
The FKA machine has high productivity. The work of the milling machine is reduced only to cleaning up the processed parts and placing new ones into the templates. This is done while the machine is running.
The F2KA double-spindle rotary milling machine differs from the single-spindle one in its more advanced design, greater power and higher productivity. He has one spindle for preliminary, rougher processing, the second for final, clean processing. Both spindles are moved onto the workpieces by supports protruding from pneumatic cylinders.
The machine bed consists of two interconnected parts resting on a common foundation plate. A table is mounted on one part of the frame, and the working part of the machine and the electric motor of the table are mounted on the second. A cylinder with compressed air is also located here if air is not supplied to the machine from the general plant air duct.
Table diameter 2000 mm, table rotation speed up to 20 m/min. The speed of each spindle is 6000 per minute. The power of the electric motor of each working spindle is 8 kW, the electric motor of the table is 2.5 kW.

USING MILLING MACHINES TO PERFORM VARIOUS JOINERY WORKS

In carpentry, a milling machine is considered universal. In addition to milling along a ruler and a thrust ring, it can be used to produce frame tenons - single to double, box tenons - straight and dovetail-shaped; choose eyes and sockets, as well as grooves - straight and dovetailed; cut drawers to size in length and width; saw the boxes to height. When processing bars, you can replace the jointer and thicknesser with a milling machine. Temporary workshops at construction sites and enterprises with a small production volume must have a milling machine.
Most of the special work on a milling machine is performed using various devices. Devices for producing frame tenons. A carriage with longitudinal and end stops and an upper clamp for making tenons and eyes for short bars. The carriage with the bars laid on it is moved along grooves in the table or along guides mounted on the table. It is best to use a lever device to press the material. A slotted disk for tenons and lugs is put on the spindle. The working techniques are the same as on a cross-cut machine.
Carriage for making tenons on long bars. Its structure is the same as that of the SHO-6 tenon cutter carriage. The carriage is movably attached to the side edge of the milling table. Working techniques are the same as on the SHO-6 machine.
A wooden carriage secured with two hinges on the wall or on a special stand. It can be made on your own directly at the construction site. Carriage for making beveled tenons (for example, on the side frames of a chair). Its structure is the same as that of the carriage for producing straight tenons, with the only change that a wedge-shaped stand is mounted on the feed slide, inclined towards the cutters at a bevel angle of the tenon. To produce tenons with a bevel in the opposite direction, direct the sled with the other end or turn the wedge-shaped stand over.
Currently, the industry produces a single-spindle milling machine FSh-3, specially adapted for the production of frame tenons. The machine is equipped with a tenoning carriage with a quick-release clamp. With this milling cutter, enterprises with a small production volume can completely do without a tenoning machine.
Devices for producing box tenons. Tsulaga box for producing straight box tenons. The processed shields (box walls) are placed in a tsulaga on the edge, clamped with an eccentric or wedge and fed to the cutters along the machine guide, along a specially installed guide bar or along a thrust ring. Slotted discs or hook cutters are put on the spindle through spacers. Carriage with screw, eccentric or pneumatic clamp for feeding shields under cutters. The shields are laid in the same way as in a tsulag box. The carriage is moved along a slide mounted on the work table.
To feed panels up to 150 mm wide in batches up to 200 mm thick, the industry produces a removable carriage with a lever for moving it and a quick-release eccentric clamp. Carriage weight 20 kg.
A device for producing through and semi-concealed dovetail tenons. This device, produced by industry, produces simultaneous tenons on two boards up to 400 mm wide and up to 25 mm thick, clamped in a mutually perpendicular position with the front sides facing inward to the right angle being formed. The thorns are cut in pairs. The cutting tool is a milling cutter that works with the side edges and teeth at the end. These cutters are often called face or zinc cutters. The device is removable and weighs 8 kg.
Devices for performing various other works on a milling machine. A template for making bars and laying them out while simultaneously cutting them off the board. This work is carried out using a typesetting cutter from a profile cutter and saw. The board is fed along a guide ruler on a template with a side roller clamp. The pressure roller has a ridge around its circumference, which enters the cut, preventing the board from moving vertically.
A device for removing the tongue and processing the ridge without readjusting the machine. The device, which looks like a box with a horizontal longitudinal partition, is mounted flat on the desktop, that is, with the wide side. The box has a through round slot through which a spindle with cutters passes. The vertical outer wall of the box serves as a side support for the workpieces. In both compartments of the box there are upper clamps in the form of scallops - wooden or metal.
A milling cutter for removing a tongue is attached to the spindle at the bottom, and a milling cutter for cutting a tongue at the top. The part (plot), passed through the lower compartment of the device, comes out of it with a tongue on the edge.
Turning the part over with the second edge facing the spindle, pass it through the second compartment of the device. From there the part comes out with a ridge on the second edge.
The device for running around the perimeter of the baseboard box and cabinet cap with rounded corners is a quadrangular board with rounded corners and four stop blocks in the corners. The shield must be precisely processed. Having placed the processed plant on the thrust blocks and fastened it to the shield with clamps or pins, overtaking is carried out with rounding of the corners along the thrust ring.
Device for cutting boxes to height. The device is made in the form of a frame onto which the box being processed is placed. Having fastened the box to the frame with an eccentric clamp, it is fed to the saws along the guide ruler. The box is cut simultaneously from the top and bottom with two saws mounted on a spindle.
The above describes only devices that are widely used. There are a lot of attachments for a milling machine, varied in design and purpose.