Device for sharpening end mills for wood. Sharpening and manufacturing of worm cutters

Milling cutter - a tool used for processing various products. Milling cutters of various types are used, which allow you to change the external and internal surfaces with the required accuracy. To achieve high productivity, the cutter must have a high condition - be sharply sharpened. Sharpening end, wood, plastic, glass is carried out using special machines and equipment.

Tool sharpening

Sharpening is carried out to restore cutting ability, with operations performed contour-wise and separately.

Cutters received for sharpening are usually pre-grinded on a cylindrical surface using a circular grinder to eliminate damage with further sharpening of the back or front of the teeth.

End mills with a pointed tooth shape are sharpened along the back surface with a special disc-shaped or cup-shaped circle. To do this, the circle is installed with respect to the axis at an angle of 89 °, which makes it possible to achieve the required contact between the contacting surfaces.
When sharpening the back surfaces of end mills, 2 main methods are used:

• polyelement;
• contour.

When using the multi-element method, the cutting edges are sharpened separately. First, the main surfaces of all teeth are sharpened, then auxiliary and transitional.
With the contour method - sharpening is performed sequentially for each tooth in one operation. A single-turn sharpening method is also used, when the cutting edges are processed in one operation. All teeth are sharpened in one revolution, the allowance is removed using a grinding operation.

Types of tool used

On the industrial enterprises apply Various types tool:

1. Cylindrical - for processing workpieces using machines equipped with a horizontal spindle.
2. End - for milling workpieces on machines with a vertical spindle.
3. End - for sinking ledges, recesses, contours (curvilinear). Are used on installations at vertical milling processing.
4. Disc - for driving grooves, grooves on horizontal machines.
5. Keyway - for grooving on machines with a vertical spindle.
6. Angular - for milling planes (inclined), grooves, bevels.
7. Shaped - when processing shaped surfaces.

For processing blanks, equipment is used that is designed for work:

• for metal;
• on wood.

Cutters with appropriate equipment are usually produced as sets with landing dimensions fasteners of different diameters. In order for the cutter to be used for a long period, it must always be sharpened, and when carrying out a working operation, it is necessary temperature regime, which does not allow overheating, which reduces their strength characteristics.

Using equipment for sharpening hobs

When processing workpieces, worm cutters are most often used.

Characteristics worm cutters strictly regulated by GOST 9324-60 and produced:

• whole;
• prefabricated (welded, plug-in).

Prefabricated hobs (for modules from 10 to 16) are used with insert dies, which are made of high-speed cast steel or forged.
Hobs (for modules 18 to 30) are made by welding and seating teeth from carbon steel on the base.

When using worm cutters for cutting cylindrical gears, the working parts of the tooth wear out unevenly.

To increase the period of use of worm cutters, a method of height correction is proposed by changing the shape of the spatial curve characterizing the workflow. The method of axial displacement of the tool is also used, which increases the speed of operations with an increase in the life of the worm cutters.

The process of sharpening hobs is carried out along the front part, and sharpened along the back surface of the tooth. After the end of the sharpening process, measurements are taken:

• front surface profile;
• district step;
• flute matching.

Types of equipment used to fix the tool

The equipment used to mount the tool is divided into 2 types:

• packed;
• terminal.

The end equipment is attached with a collet and a chuck, and the nozzle equipment is used by mounting it on the spindle using a special mandrel.
For fixing the tool, mandrels of 2 types are produced:

• center;
• terminal.

Center bars are produced with a tapered shank, which has dimensions corresponding to the hole in the spindle, and is produced in 2 types 7:24 and Morse taper.
Allowed when using of this type mandrels to install several cutting tools with fixation with special rings.
When using a cylindrical end mill, a collet chuck is required. Usually the equipment includes 7-11 collets allowing you to pick up required size for secure fixation.

Tooling for fixing the workpiece

To carry out the milling process, it is necessary to fix the workpiece, for which they are used:

• rotary tables;
• vise;
• clamps.

Rotary round tables are used for milling workpieces with a curved surface.
This type of tables has a wide range of offsets:

• rotation;
• changing the angle of inclination of the table plane;
• the possibility of processing products in a vertical position.

Clamps or clamps allow you to fix products with the help of special elements, which in turn are attached to the table with bolts and nuts. For fixing small-sized workpieces, a vice is used, simple and with a rotary mechanism.

Using accessories

To fix parts having a cylindrical shape, a three-jaw chuck and special centers are used, which, with the help of clamps and lunettes, carry out fixation, as well as the use of dividing heads. These fixtures are used to process parts at a given angle during rotation.
The dividing head consists of the elements:

• corps;
• swivel pads;
• spindle.

A three-jaw chuck is attached to the spindle, designed to fix the workpiece, the other end, which rests against the headstock. The block can rotate with fixation at the required angle. When processing a long workpiece, steady rests are used for fixing.

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We sharpen:

• incisors
• dolbyakov

Correctly performed tool sharpening reduces its consumption and, accordingly, increases its resource. Therefore, it is necessary to carefully monitor the condition of the cutting edges and perform timely sharpening of the tool, avoiding excessive wear and, moreover, its breakage.

Sharpening and manufacturing of worm cutters

The production complex of the Spetsstanmash plant offers a full range of services for the manufacture and repair of metal parts and structures, including: the production and sharpening of milling cutters for metal, wood, cast iron, aluminum, graphite or plastic.

The cutter is important tool in industry and workshops. Represents a detail of various shapes, with distinctive feature sharp teeth. Its main function is the mechanical processing of the harvested material.

The principle of operation of milling is the translational rotational movement of the teeth of the cutter.

Depending on the type of tool used, the result is obtained:

• small grooves or grooves when using end mills;
• milling large surfaces;
• baguette cutting, window frames, gear, etc. by means of spiral cutters,
• cutting with a disk cutter (plinth, panel, clapboard lining, wall beam, etc.).

An important characteristic of the cutter is the material of its manufacture, in particular the cutting part. These can be teeth made of high-speed steel, mineral-ceramic, cermet or diamond.

Diamond cutters are considered the most durable due to natural physical characteristics. But, they are the most expensive. All other materials become dull after some time during operation, especially if they are not used correctly. Purchasing new tools is expensive, but our skilled craftsmen and high-precision modern equipment allow the quality to perform such a type of repair as sharpening knives for cutters of any geometry:

• sharpening of worm cutters
• sharpening of disk cutters
• crown cutters and other types.

Professional work on sharpening cutters increases the durability of the part, and significantly reduces the consumption of cutting teeth.

Sharpening worm cutters: from 600 rubles / PCS. (depending on wear)
Minimum sharpening time: from 10 working days
Minimum order amount: 3500 rub.
* The exact cost can be found using the form or by phone

The cutting tool becomes dull sooner or later. If it is disposable, then there is only one way out - to the landfill. But the cutting edge of expensive devices can most often be restored. in this article we will tell you how to give them a "second youth".

Different cutting tool requires differentiated approach when sharpening. Today we will talk about the restoration of chisels, planers, wood cutters and metal drills.

Sharpening chisels and planers

Lead in working condition a chisel or a planer knife is not so difficult. The sharpening procedure consists of only two stages. When working on sharpening a tool, you will need a regular grinder. Chisel or planer knife for soft rocks wood is sharpened at an angle of 250 °. For hard rocks - 350 °. When sharpening, always hold predetermined angle, which is not so easy. To simplify the task, special devices for sharpening chisels can be used, allowing you to work in the range from 25 to 35 °. To prevent overheating, periodically cool the instrument in water.

Do not immediately grind the edge of the iron until the cutting part appears. When bringing its thickness to half a millimeter with a square, check that the axis is perpendicular to the cutting edge. Final sharpening is best done by hand or on a low-speed, water-cooled grinder, bringing the tool to the required sharpness. cutting edge.

When sharpening a round chisel with an outer edge, the tool moves along the bar from edge to edge along the entire length of the stone, describing the "eight". Burr with inside the groove, which is necessarily formed during sharpening, is removed using a shaped whetstone. The final sharpening of the cutting edge is carried out sandpaper varying degrees of graininess.

Sharpening cutter for wood

For sharpening shaped end mills, it is not necessary to have special tools. It is enough to have a diamond bar laid on the edge of a table or workbench. The cutter is sharpened by holding its front surface along the bar, previously cleaned of resin residues, dirt and dust with a solvent.

If there is a guide bearing, it must be dismantled before sharpening. An attempt to save a couple of minutes will result, if not in its deformation, but, quite possibly, in a damaged cutter. In the process of sharpening, the bar is slightly wetted with water, and after completion of work it is wiped dry. As the front surface is ground down, the edge of the cutter will sharpen and its diameter will decrease slightly.

When sharpening tools, you should use whetstones of different grain sizes, depending on the desired end result and the cleanliness of the surface to be treated. When sharpening incisors to maintain symmetry, a multiple number of movements is performed with equal pressure. Depending on the material from which the cutter is made, instead of a bar, abrasive paper mounted on a strip of steel or a wooden lath can be used.

If you have a low speed grinder at your disposal, then installing the appropriate abrasive wheel can reduce manual labor to no.

Sharpening a drill for metal

Over time, drills become dull and many simply throw them away, buying new ones. However, almost always the drill can be given a "second chance" and extend its life. To do this, it is enough to process a dull surface on a grinding wheel.

Before starting work, stock up on a container of water into which the drill will be dipped from time to time to avoid overheating. Sharpening is carried out sequentially and begins with the processing of the back surface, gently but tightly pressed against the surface of the grinding wheel until a regular cone is formed.

After that, its cutting part is sharpened and the final finishing of the back surface is carried out. During sharpening, you must constantly monitor the jumper at the tip of the drill. For drills with a diameter of 8 mm or less, it should not exceed 0.4 mm. For large samples, the size of the bridge varies from 1-1.5 mm. Keep in mind that drilling does not produce a tip, but the sides of the drill!

electric grinder

Structurally, electric grinders are extremely simple.

They consist of induction motor, grinding wheels and casings. Having transferred the conversation to the plane of choosing a specific manufacturer and model, it should be noted that if you are planning to buy a device for personal purposes, then the brand is not decisive. Such equipment is included in the network for a short time and has a rather large resource. The price of a sharpener directly depends on its diameter.

The larger it is, the more expensive the device. When inspecting an electric grinder before buying, try to move the shaft. If it not only rotates, but also “walks”, discard it and choose further. Of course, it is best to include a sharpener in the network, but not every store will meet you halfway in this matter.

Electric grinders or grinding machines are divided into three groups:

1. High-speed sharpeners equipped with interchangeable holders for various kinds tool.
2. Highly specialized machines designed for a specific tool (for example, drills).
3. Low speed water cooled machines.

If high-speed sharpeners spin up to 3000 rpm, then such machines rotate at a maximum of 150 rpm and can sharpen any cutting tool. Low speed and water cooling - ideal conditions for a quality cutting edge.

Enough is being produced today a large number of cutters of various sizes. They can be classified according to functional and constructive qualities.

Sharpening of end mills is carried out using special devices for such tools. In some cases, sharpening can be done manually.

The cutters have a relatively large length and uneven teeth for cutting. In the process of sharpening, you will need to take care of the movement of the base of the circle along the edge. In this case, it will be necessary to sharpen the shaped cutters that have a backed corner. You should know that sharpening is quite difficult. To preserve the profile of the structure and facilitate the sharpening process, the backed teeth will need to be sharpened exclusively along the front base. Sharp teeth, which have a flat or curved shape, must be sharpened exclusively along the back base. Slotting and parting cutters can be sharpened on the front and back bases of the teeth.

Tooth geometry

The geometry of the teeth of the cutter: a - sharpened tooth, b - backed tooth.

To sharpen correctly, you need to know the geometry of the teeth of the cutter. According to the design of the teeth, cutters with backed and sharp teeth are distinguished. In the latter, the part of the rear base, which is adjacent to the cutting edge, is a plane. Teeth with sharp ends in most cases are sharpened along the back base, but they can also be sharpened along the front base of the tooth.

The backed teeth, which come with end mills, have a back base made in the Archimedes spiral. It is quite difficult to process a shaped base technologically, therefore it is possible to sharpen cutters with backed teeth only along the front base.

Regardless of the number of teeth in the cutter, each of them can be considered as a separate tooth, which is characterized by typical parameters for a tooth - the angles of the front and back, the size of the grinding area, and the angle of the teeth.

The sharpening platform is an element of the back base of the tooth, which is subjected to grinding during sharpening along the back base. On this basis, the maximum wear of the teeth will occur. Its size affects the magnitude of the friction force between the tool and the workpiece, so the base must be maintained in a specific range.

The scheme of sharpening prefabricated cutters on a universal grinding machine.

The basic rake angle is the angle between the tangent to the front base and the base of the axis. It can be measured in a plane that will pass through a given point perpendicular to the main cutting edge.

The main back angle is the angle between the tangent to the back base at given point the main edge for cutting and the tangent to the plane of rotation of this point. This angle helps to reduce friction between the tool and the workpiece.

With the help of the auxiliary rear angle, it is possible to characterize a large gap between the milled base and the body of the clove. It is necessary to sharpen the tool along an additional angle with a specific amount of damage to the tool and an increase in the area for sharpening. The purpose of this action is to reduce friction between the tooth and the workpiece to be milled. You should be aware that not all tools of this type have this angle.

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How to sharpen end mills for woodworking?

The shape of the teeth can be straight or helical. The inclination of the tool teeth can be described as the angle between the developed edge of the helical type and the axial part of the tool.

The values ​​of the tooth angles will depend on the type of tool, the grade of alloy and steel from which it is made, as well as the type of material that the tool is intended to mill.

When milling viscous materials, the main rake angle should be selected in the range of 15-20° or more. For instruments from solid metals for steel milling, the angle will be 0° or -5°. The rear angle varies over a wide range.

Items you will need:

1. Diamond beam.
2. Table.
3. Water or soapy solution.
4. Solvent.
5. abrasive paper.
6. Hardwood plank or steel strip.
7. abrasive circle.

It is possible to sharpen shaped end mills without special devices for sharpening, along the front base, with a diamond bar of small thickness. The beam must be installed on the extreme part of the table. If the tool has a large recess, then the tool must be fixed along the table.

Heat resistance table various materials, °C.

When sharpening, the timber will need to be moistened clean water or soapy solution. After sharpening, the tool will need to be washed and dried.

In the process of sharpening the front base, the edge will become sharper, but the diameter of the tool will decrease slightly.

If a bearing is installed on the tool, then the first step is to dismantle it, and then sharpen it. Trying to save time in this case may end up with a damaged bearing and a broken cutter.

Be sure to clean the cutter from excess resin from trees. For this, it is best to use a solvent.

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In the process of sharpening tools, it will be necessary to use bars of different grain sizes. The grit will depend on the thickness of the removed layer of material and the desired cleanliness of the base. Before sharpening, you will need to make sure that the timber has the right shape.

Figure 1. Grinding wheel shapes.

If the cutter teeth are made of relatively soft material, instead of a bar, you can use abrasive paper, which is glued to a flat base. As a base, you can use a plank of hardwood or a steel strip.

End mills for milling wood are sharpened on a special device with a low speed of rotation of the circle. In this case, you will need to use a suitable abrasive wheel.

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Sharpening wheels

Sharpening of modular cutters can be done with circles of white or ordinary electrocorundum, diamond and others. For example, using electrocorundum wheels, you can qualitatively sharpen milling cutters for working with metal and wood, which are made of tool or other standard steel. Elborovymi circles have the ability to sharpen high-performance steel structures. Silicon carbide and diamond wheels are used for sharpening hard metal cutters.

By increasing the temperature, the hardness of such a device decreases. A temperature of 1000°C can reduce the hardness by almost 2 times. At a temperature of 1300 ° C, this indicator will decrease by about 6 times.

Figure 2. Sharpening of the end mill: a - the main cutting edge, b - the auxiliary cutting edge, c - installation diagram of the cutter for sharpening the teeth of the auxiliary cutting edge.

The use of water to reduce the temperature in most cases leads to rust on the workpieces and corners of the machine. To eliminate corrosion, soap and some electrolytes must be added to the water, which can form films for protection. When grinding, a solution with soap or soda is almost always used. If fine grinding is performed, then a low-concentration emulsion should be used.

In order to increase the quality of grinding with an abrasive wheel and reduce significant damage, it is recommended to select the maximum grit that can provide required class the cleanliness of the base of the cutter used.

The circumferential speed of the wheel during sharpening of hard metal teeth should be approximately 15-18 m/s. For example, in the process of using a circle with a diameter of 12.5 cm, the engine speed should be approximately 1600-2700 rpm. If it is necessary to sharpen more brittle materials, the operations must be performed at a lower speed. When using hard metal tools, the use of a hard mode leads to high stresses and cracks, and in some cases damage to the cutting edges. Wheel wear in this case will increase.

The shape of the circle for sharpening the back corner of the teeth on the basis of a cylindrical shape should be cup or plate. To sharpen the front corner, you need to use a disc-shaped or flat-shaped circle.

The existing forms of grinding wheels can be seen in (Fig. 1).

The cutter is a type of round rotary cutter. It always has a circle in its cross section, and the shape itself can be any, including very complex ones. Along the circumference are furrows (there are different depths) or teeth. They process the material during the rotation of the cutter. is a complex and painstaking process. It is important that not only the specialist has a certain level of skill, but also sharpening tool met the highest requirements. Otherwise, chips, cracks or unsharpened areas will remain on the cutter after processing, which will directly affect the further execution of milling work.

Varieties

Incisors are the most different types- end, end, disk, slotted, cylindrical, slot. And this is not all varieties. They are also divided according to their purpose and are angular, shaped, keyed, for T-shaped grooves. Another division - according to the type of surface to be treated:

• for metal;
• on wood;
• on plastic;
• on glass;
• other.

Sharpening cutters for metal complicated by a large length of the cutting surface. Such work is possible only with the use of special tools. In some cases, you have to grind by hand, but for this you need to have a lot of experience. Otherwise, all previous work will go down the drain. Notches, notches, chips and cracks will appear on the grooves (teeth). The part will have to be re-grinded, which invariably reduces its size.