Used abrasive compositions
The initial requirements according to GOST are resistance to frictional wear (moreover, with the combined action of high pressures and sliding speeds), low thermal conductivity and increased surface hardness.
Depending on the intensity of application, GOST 28818 allows the use of the following materials:
- Electrocorundum on a bauxite component, the basis of which is a high-percentage aluminum oxide Al2O3 with the addition of calcium oxide. This chemical compound is characterized by increased hardness, which is also retained at high temperatures occurring in the grinding or dressing zone. Marking circles made of electrocorundum – from 12A … 15A for normal, up to 22A … 25A – for white. With an increase in the index, the strength of the wheel increases due to an increase in the hardness of the base material..
- Electrocorundum on a carbide basis. Most often it contains chromium, titanium, zirconium and silicon carbides. Marking starts at 38A (for zirconium) and ends with 95A (for chromium and titanium). Carbides of these metals have an increased resistance to shear stresses, and therefore are suitable for removing the surface layers of parts that have undergone heat treatment, or for straightening them. The presence of silicon carbide (marking 52C … 65C) increases the resistance against temperature extremes.
- Spherocorundum is a material that is obtained by blowing molten aluminum oxide, resulting in the final spherical shape of the grains (in electrocorundum, the grains are mostly flat). The marking of this composition is ES, and it is distinguished by an extremely high hardness. This circumstance allows the use of spherical corundum for grinding materials of increased hardness, including even hard alloys..
- Mono-corundum (marking – 43A … 45A), where the grinding grain, unlike other types, has a monocrystalline structure. This increases the durability of the abrasive composition, but at the same time increases its cost, since the technology for growing single crystals is very complex. A more accessible variety is aggregated mono-corundum, in which poly- and monocrystalline areas are combined in a certain way..
The grain size is set in accordance with GOST 3647, and is also noted in the marking.
Fastening of the abrasive component to the base is carried out using rings, flanges, fiberglass discs, etc..
Marking is determined by GOST 2424, and includes the following varieties:
- for operations of rough (rough) grinding of metal, internal or external, dressing mainly with the periphery – circles with a straight profile (PP);
- for processing threads, and other periodic profiles on metal – conical double-sided (2p), or disc-shaped (t);
- for sharpening and dressing cutting saws of friction – conical one-sided (3p);
- for centerless metal grinding – wheels with one- or two-sided grooves (pv);
- for face grinding with a flat surface – annular (k).
Decoding the abrasive grinding wheel
A separate category is sharpening, dressing, and grinding of friction surfaces of metalworking machines. Such circles are called cup circles, and are marked with CZ or CK..
Grinding wheel label decoding
The above nomenclature refers to solid wheels that perform an operation with their entire working perimeter (dressing, rough grinding). When using inlaid grinding wheels, special segments are used, which are installed in the corresponding seats of the wheel body on a machine or typewriter. They are produced in accordance with the technical requirements of GOST 2464. Stacked segments can be used to process hard-to-reach surfaces (for example, rail depressions, narrow grooves in metal or stone). Grinding segments are more economical in dressing and allow for easier routine maintenance of the machine.
Grinding wheel marking scheme
Abrasive Grinding Wheels
Abrasive grinding is one of the main types of rough grinding, which is performed with the aim of reducing surface roughness, straightening, and eliminating periodic relief that appears on a part after machining on machines. The laboriousness of the final readiness of the product depends on the correct choice of the grinding wheel, and its ability to better withstand the emerging frictional loads..
Types and technological application of grinding wheels
Abrasive rotating grinding is carried out using:
- cutters (cones);
The quality after grinding depends on the grade of the grinding wheel. There are three known of them: A, B and AA. Grinding wheels of class B have the lowest accuracy, and AA wheels have the highest accuracy (they are usually equipped with precision grinding machines). The accuracy of the grinding wheel is determined by its geometry, the composition of the abrasive material on the wheel, as well as the grain size.
In the practice of grinding or dressing on machine tools and hand-held machines, one-time fastening of the composition to the base is often used. In fact, it is sanding paper with a velcro backing. Such velcro “circles” are used mainly in everyday life, for hand-held machines, moreover, with a slight removal of metal, in particular, when straightening.
Grinding cloth wheels for profile grinding
On the contrary, when removing a significant amount of metal, home craftsmen often use cones – attachments for an ordinary electric drill, which outwardly resemble a milling cutter. The roller cutter, rotating at high speed, performs rough grinding of surfaces after drilling or milling work. The cones are compact and have a small working surface diameter. Rollers, however, cannot provide high torque..
Role of ligaments
In addition to the cutting substance itself, the method by which it forms the abrasive mass is also important. GOST allows the use of bakelite or ceramics as bonds. The bakelite version is good for its higher density, therefore, the wheel is characterized by increased weight, suitable for work on metal, but with a limited peripheral rotation speed (especially if a hand grinder is used). The use of ceramics makes the grinding wheel lighter, and the permissible speed of its rotation on the machine increases accordingly. However, the abrasion resistance as well as the hardness of the ceramic wheel is reduced.
How We Make Our Wheels
The bundle also determines the method of attachment to the base of the case. For example, foil bonding is suitable for ceramic bonds, but not suitable for bakelite bonds..
A special type of ligament is fiber. Such a base is used in the so-called “cold” grinding of metal on a machine or machine, when cleaning the stainless steel surface or the weld zone. In this case, the processed material practically does not heat up, since the depth of the grinding zone is insignificant (the process is actually closer to polishing). Marking is carried out in accordance with the standards of GOST R 51967.
Other types of binders are also limitedly used – from various epoxy compositions, magnesite, porcelain.
FELT FORMA – How we make felted wool boots – wet felting process
How to choose the right size and type of tool
The choice depends on the processing conditions, the main equipment used (machine or manual machine), as well as on the material to be grinded..
The manufacturer also matters. Among consumers there is a jargon designation of the instrument – “Luga” and “Volga” circles. In the first case, the manufacturer is OJSC “Luga Abrasive Plant”, and in the second – OJSC “Volzhsky Abrasive Plant”.
The products of the Luga plant are used for both circular and flat grinding. Luga circle is suitable for both a machine tool and a manual typewriter.
Cutting abrasive wheel device
When choosing a domestic manufacturer – Volga or Luga – they are guided by the following practical recommendations:
Buying an optimal circle according to GOST of one standard size (Volga or Luga) is an unrealistic task in most situations. When using a manual clipper, you need a wheel that can withstand the maximum number of revolutions, and when working on a stationary machine, you will need a tool that can withstand higher pressures.
How to make a do-it-yourself grinding machine: instructions with step-by-step photos
How to make a do-it-yourself grinding machine: instructions with step-by-step photos
Magnetic plates are used in the processing of metals on various types of machine tools. First of all, these are grinding machines, where the use of a magnetic fixation method allows you to provide maximum access to the treated surfaces and exclude their mechanical damage. They are also used on milling and turning machines, during welding, during assembly operations and in other cases..
Magnetic plates are widely used due to reliable fixation with a relatively compact size. Another important advantage is maintaining the accuracy of the installation throughout the entire life of the product. This type of equipment is rarely included in the basic set of the machine, and therefore they must be purchased and installed separately, taking into account the size, clamping force and other parameters of the product..
You can make a simple typewriter from your PC’s hard drive. To do this, you will need the hard drive itself, an abrasive, a PC power supply. It will be designed to work with small details. When disassembling the disc, glue the abrasive onto the rotating surface. After that, the structure must be connected to a power supply unit (power supply), and then the entire structure must be fixed on the working plane of the table, equipped with a speed controller, a switch.
Do-it-yourself wood sander
Grinding machines are represented by the following types:
- eccentric or orbital;
When making a typewriter, you will need:
- electric motor;
- source of power.
The power unit must be taken from household appliances, for example, from a fan, the power supply is a computer, the battery is a household one. As a basis for the above elements, a wooden board is suitable, on which the battery with an electric motor should be fixed with screws. The “start” button must be attached to the base with self-tapping screws. Wire strands are secured with industrial staples.
The working part of the tool is a grinding wheel, which you can purchase yourself. The abrasive disc will be driven by an electric motor using two bushings.
You can strengthen the design of the device if you take a motor from a washing machine as a motor. In addition to polishing discs, in this case, grinding and abrasives can be installed on the tool..
Homemade belt sander
How to make a mini sander with your own hands
First, you need to find some Styrofoam to prepare the base for the device. After that, you need to cut a hole to install the switch in it. Then you will need electrical tape and a power source, for example, the famous Krona battery. We fasten the power battery (Kronu) to the foam base with electrical tape. We take the cork from under the champagne and the core of the handle. We cut the rod to the desired length, after that we put the handle rod on the cork with a blunt end and insert the tip of the rod into the hole for the motor shaft. After that, you need to cut a strip of abrasive tape with scissors to fit the size of the plug. After you have cut the tape, it should be glued around the cork around the circumference. This cork construction will be the working part of the machine. We carefully inspect all the wires and connect them with twists, insulate the connections with electrical tape. We are trying to launch the resulting device. Now you have your own mini car. Such a device is useful for performing simple small jobs for which an ordinary grinder will be too large and inconvenient. If you are an observant and patient, as well as a diligent person, making a sander with your own hands is not at all difficult. To do this, you only need dexterous hands and a little patience..
The main factor in choosing a grinding wheel is the parameters of the material being processed and the scope of application (machine tool, hand tools). Another important factor is the quality of processing, which is determined by the grain size of the wheel. The larger the grain size, the higher the rate of removal of the surface layer, but the lower the surface quality. For this reason, fine grinding wheels are used for fine grinding..
The table below provides information on the choice of grit depending on the grinding operation..
It is desirable that the circle corresponds to the material for which it is intended. This is indicated in the manufacturer’s recommendations, in particular in the form of an image on the label. Pay attention to the permissible rotation speed, which is an important condition for safe work..
The profile of a circle determines its applicability for certain operations. Let’s list the most commonly used types of profiles:
- Flat with a straight profile – internal or centerless grinding, torus machining and other operations.
- Flat double-sided with tapered profile – machining gears and simple threads.
- Flat grooved – cylindrical grinding, end trimming.
- Cylindrical and conical circles – tool sharpening and other operations.
- Disc wheels – sharpening tools with multiple cutting blades.
You can determine the main parameters of the circle by its symbol, which is indicated in the product labeling. The symbol corresponds to GOST R 52781 and indicates:
- circle type;
- geometric parameters (outer and inner diameter, height);
- type of ligament;
- structure and degree of hardness;
- highest permissible processing speed.
The exception is wheels with individual markings, which have wheels of foreign manufacturers. When purchasing this product, you need to study the information in the catalogs and on the packaging..
Grinding wheel grit
Granularity is one of the main parameters for choosing a grinding wheel for performing certain operations. It is determined by the size of the grain, subdivided into fractions in accordance with the group of grinding material and is indicated by the corresponding numerical value.
There are three main groups in total – grinding grains, grinding powders and micro-grinding powders. In the first two groups, the grain size is determined by the smallest grain of the fraction in hundredths of a millimeter. So, for example, 40 means a particle size of 400 microns or 0.4 mm. In the third group, micro-grinding powders, the numerical value determines the largest grain size in the fraction in microns and has the additional designation M. For example, M20 is a circle with the largest grain size in the 20 micron fraction.
The table below shows data on the grain size of the groups in accordance with GOST 3647-80 and the international standard ISO 8486.
- Scope of application
- Grinding wheel grit
- Selection rules
A grinding wheel is an abrasive tool consisting of grains of a certain fraction, cemented together by a binder. It is a body of revolution with a standard outer and inner diameter, with a certain surface configuration that is optimal for performing certain operations.
Scope of application
Grinding wheels are used for preliminary and finishing processing of products made of ferrous and non-ferrous metals, plastic, wood and other materials. The scope of a circle is determined by its grain size, diameter and surface shape. With the help of a circle, it is possible to process flat and shaped surfaces, ends, threads, holes, etc..
The main field of application of grinding wheels is mechanical engineering and machine tool construction. Depending on the geometry, they can be equipped with sharpening machines, hand-held electric or pneumatic tools. They can also be used for manual operations. A wide range of tools allows for a wide range of operations – from roughing and roughing to finishing sanding and polishing.
Operation and technical conditions of grinding wheels are regulated by a number of Russian and international GOSTs. In particular:
- GOST 3647-80 and the corresponding ISO 8486. regulates the graininess of the wheels.
- GOST R 52588-2011 – defines the safety requirements for the tool.
- GOST R 52781 – regulates the specifications of grinding wheels.
There are other standards that define the parameters of different types of grinding wheels..
# homemade # instructions # repair_technique # inventions
# homemade # instructions # repair_technique # inventions
Homemade nozzles / cutters / consumables for the engraver, drills and drills
Homemade nozzles / cutters / consumables for the engraver, drills and drills
The article will touch upon the topic of how to make consumables with your own hands. It’s no secret that the Chinese tips are of very low quality, while the branded ones have a bite. So in some cases it will be more profitable to do it yourself. Under the cut you will see my homemade nozzles and also interesting solutions from the Internet..
Petal circle for engraver
Native emery on a rubber drum do not last long, so you need to find an alternative solution. Cut a small diameter circle out of plywood:
We give a smoother shape:
We make cuts with a hacksaw for metal:
We glue emery into the resulting slots on epoxy resin:
Larger nozzle. So that the “spreading” does not turn out as in the previous version, when gluing the emery needs to be pulled off with an elastic band. This is due to the fact that the base of the fabric absorbs the resin from the cut and coarsens.
The advantage of the petals is that they serve an order of magnitude more than ordinary emery on a drum of the same diameter.
Emery for drills from rollers from a tape recorder
Older reel-to-reel tape recorders have large rubber rollers with a metal sleeve. We put a bolt on the sleeve, and glue emery on the rubber:
Cutting discs for engraver
The topic is fairly common, but I’ll tell you for completeness..
We take a thin cutting disc for an angle grinder, a compass with two needles, an awl, and unnecessary scissors:
1) Draw circles with a compass (you should not make too large circles, it is inconvenient to work with them. The optimal size is a little less than a standard circle) Make sure that the center of the circle is in the middle of one of the squares of the reinforcing mesh.
2) Cut the disk into sectors with scissors, and then cut out the circles themselves that are in the sectors. For this work, metal scissors are suitable, but you can also do ordinary clerical ones, only they become more blunt from this, so we take those scissors that we do not mind.
3) With light rotational movements of the awl, we begin to make a hole alternately on both sides. The hole diameter must be equal to the screw diameter. If the hole is slightly larger, it will break.
4) We grind a circle at low speeds on an unnecessary whetstone:
And we get reinforced cutting wheels:
Making such circles is much cheaper than buying them. They also last longer than purchased unreinforced circles..
Decorative sanding attachment
A self-tapping screw without a cap is screwed into the cork, and a washer is glued to the base. The chuck jaws will rest against the washer and prevent the self-tapping screw from screwing in deeper.
It is most convenient to use such a nozzle on a drilling machine. Instead of a self-tapping screw, you can screw a felt nozzle into the cork:
Drill polishing head
Another fairly common topic. The felt from the felt boot is clamped with a bolt with wide washers. A polishing paste is applied to the felt, for example GOI paste.
The following are some examples of abrasive nozzles taken from the Internet..
Drill grinding drum
Grinding drum for engraver
On a lathe, a metal drum with a slot is turned into which the edge of the nadjack is tucked in, and it is wrapped around the drum. Fixation takes place with an elastic band. The same structure can be made from plywood, as shown in the previous version..
Grinding cylinders for engraver
Comrade Marshall proposes to make cylinders in this way, I quote:
In order to make this type of expenditure, we need: strong, but as thin as possible fabric (preferably cotton), a skin of the desired grain size, and most importantly, a tube of a suitable diameter, on which the cylinders will be located during gluing.
So, take the fabric and cut it into long strips 12 mm wide. Then we cut these strips to the size of the diameter of the tube with an overlap of about 1-1.5 cm, pull them tightly onto the tube (so that they do not chatter) and glue our pieces right on the tube using ordinary PVA. Further, the task is a little more complicated: you need to correctly make a stencil, according to which the skins themselves will be cut in the future. The stencil is shown in the figure on the right under the tube. We do this: take, cut off a piece of skin the same width as the takan, but 1 cm longer. We apply it over the glued fabric and mark the place where the joint of the two ends of the skins should be. After that, we do the necessary geometric actions: from the point of the proper joint, we draw a fishing line across the skin, from the other end of the skin, at the same distance we do the same, after which we draw diagonals in the formed rectangles and cut off pieces of skin along these diagonals. Now, when you apply your stencil over the fabric glued to the tube, you get a precise diagonal connection of the ends of the skin. Now you have a stencil that you can trace with a pen along the contour on the back of the sandpaper..
Further, it is quite simple: we glue the strips of fabric until there is no space on the tube. Next, cut out pieces of skin using a stencil and glue them over the fabric with the same PVA or better “Moment”. To prevent the skin from unfolding before it sticks, you need to press it with an elastic band or a strip of electrical tape. After drying, it may turn out that your craft is stuck to the tube, so after applying the glue, it is necessary to turn the blanks around its axis a couple of times at different times. Also, in order to avoid gluing the workpiece to the tube, you cannot use super – glue and the tube should not be wooden.
Milling cutter from a lighter wheel for a drill or engraver
If the nozzle will be used in a drill, then we put the wheel on the bolt, if in the engraver – instead of the cutting wheel:
This cutter easily cuts wood, plastic and soft metal..
Dowel drill bit
We grind off all unnecessary irregularities from the cap. With the cut-off wheel of the engraver, we make cuts at an angle and get a cutter:
A variety of drills and cutters. It is convenient to use a center cutter to cut holes in materials with a small thickness. In a metal block, you first need to drill holes for a drill and a cutter, then for clamping screws and cut a thread in them.
If the center cutter will be used in a drill, then instead of a drill, you need to install a metal bar. The cutter is made from the shank of a broken drill.
They can also cut washers, for example, from fiberglass from soldered boards:
One book suggests making a cork cutter. As far as this is a good idea, I cannot download, since I myself have not tried to process anything with such a cutter. I think that for very soft materials it will work.
A couple of designs of cutters from the Internet
Electric razor cutter
Comrades on the forum suggest using an electric razor knife as a cutter. But there is one problem – the direction of rotation of the knife is reversed, so a drill with a reverse is needed..
Milling cutter from a hacksaw blade
Add your attachments and suitable options from the Internet to the comments.
There are three main designs of wood grinding machines:
1-Disc machine 2-Band machine 3-Drum machine
A disk machine is a rotating disk, on the plane of which an abrasive (sandpaper) is fixed. Grinding is done by applying the edges or side surfaces of the part to the disk, for which a table or support bar is installed approximately in the middle. This design is ideal for sanding straight or convex edges..
The belt type consists of two drums installed either vertically or horizontally. One of them is drive, the second is tension. The abrasive is a loop of sandpaper that is glued together in a pattern. The loop is installed on both drums and pulled. After starting the engine, it forms a constantly moving abrasive strip. Grinding is done by pressing the tape to the surface of the part using a special clamp (“ironing”). It moves left and right, ensuring that the sandpaper is pressed against all areas of the treated surface..
The drum machine is used for grinding concave edges. It is a rotating cylinder of relatively small diameter (6-8 cm), on which the abrasive is installed.
The simplest designs are disc and drum. Making a band machine is much more difficult, but its efficiency is much higher. Such installations allow high-quality grinding of panels and parts of a large area, providing high surface quality..
Wood sander: how to make it yourself?
Sanding wood is a mandatory procedure prior to finishing. To carry out the work, special machines are used, operating on a different principle and grinding material in a different direction. However, the price of such devices is quite high. It is not always advisable for a home craftsman to purchase equipment that will be used from time to time. It is more correct to make a wood grinding machine with your own hands, which will be much cheaper and will allow you to get a completely effective device.
Features and specifications
The main feature of wood grinding machines is a specific way of adjusting the quality of processing. It occurs by changing the grain size of the abrasive. Usually, the process begins with coarse-grain sandpaper, then its size is gradually reduced and the procedure is completed by grinding with a fine sandpaper. In total, 2-3 shifts are used, but there may be more gradual methods..
The second feature is the way the abrasive is installed. If a pre-glued loop is installed on a tape machine, then a circle of sandpaper should be fixed to a plane on disk structures. The best way is to use Velcro, but the easiest way is to stick the abrasive onto the adhesive or double-sided tape. The second method is easier, but also more expensive..
The technical characteristics of each machine are slightly different from each other..
For disk installations:
- Working body diameter.
- Rotational speed.
In order to get a grinding machine of any design, a base (bed) is needed – this is a body on which a structure for an abrasive part will be installed and a place for installing a motor will be allocated. The base blank can be wooden or metal. For a self-made unit, such dimensions of the bed are enough: 50 × 18 cm with a thickness of 2 cm.
It is best to make a base of metal. Such a design will be more reliable, it will be used for a longer time, it will not succumb to deformations of various types. But within the framework of home use, a wooden machine will also become the best option, especially if the model is not stationary (sometimes it will be moved or transported).
In addition to the material for the manufacture of the bed, other devices are also needed – a motor, rollers, an abrasive element.
DIY grinding machine – manufacturing instructions
In the process of working with wood products, the moment comes when you need to make the surface perfectly smooth and remove some defects. For this, special grinding machines are used. For non-professional use, you can make a do-it-yourself grinding machine. A tool for a tree of such a plan can have a variety of designs that you can form yourself. Moreover, each design involves working with certain types (length, density, shape) of wooden parts.
Disc sander manufacturing
Making a disc sander with your own hands at home is the easiest way. Usually a body is formed, and an angle grinder or drill is used as the main part that drives the abrasive wheel. But an asynchronous motor from an old car can also be used..
You can use a new generation of motors that correspond to the required parameters, but it is worth preparing for the brushes on it to wear out quickly.
If everything will be created from scratch, then you should act according to the following plan:
- Prepare a rough drawing to create a disc sander.
- After careful measurements and drawing up of drawings, it is worth getting to work. A base is formed from vertical and horizontal parts, which must be fixedly fastened to each other, by means of metal construction corners. A round hole is cut in the vertical part, where the motor pulley will be output. The “propelling element” must also firmly attach to the horizontal part of the base.
- The next step will be to attach the disc-shaped part to the moving part of the motor. You can make a disc out of plywood and attach it to the motor pulley with bolts. In this case, the bolts must completely coincide with the surface of the disc..
It remains to cut a circle of the required diameter from the abrasive cloth and attach it to the disc part. Such a machine can be operated from the network. If you wish, you can complicate the design by thinking over a push-button control panel.
Design features and operating principle of the machine
The device of a grinding machine for wood is not complicated, since the main task of any model is to process one or another type of wooden part, forming the required surface parameters for finishing. Thanks to processing with a grinding machine, the surface of the wood becomes perfectly smooth, and the parameters of the workpiece are additionally calibrated.
In production, a device of this type is used, which is equipped with a disk, a belt, a bed (for tilting processing). The functionality of homemade devices is not so wide, but this is usually enough for processing wood parts. There are several options as to how the homemade woodworking machines are arranged..
Usually, homemade grinding machines are made using improvised tools. But in any case, you need either an axis for attaching the grinding wheel, or 2 shafts, between which the grinding belt will be pulled. To set in motion a base with a grinding element, it is necessary to additionally prepare a motor with a power of no more than 1 kW.
A do-it-yourself wood grinding machine has the following principle of operation – due to the use of a belt with different abrasive spraying, the required surface treatment occurs. If a belt abrasive element is used, then its fixation is performed by pulling it between two drums. A hard backing is required to hold round abrasives.
Types of grinding machines
When working closely with wooden parts and objects, the master needs to know what kind of grinding machines for wood are in order to select the most optimal device for himself.
According to the principle of the device, the types of wood grinding machines are divided into 3 types: belt (grinder), disc, drum.
- The band machine is considered the most common. The coated abrasive belt is mounted on two shafts that drive an asynchronous motor. In this case, the grinding element can be located in a horizontal or vertical position. In the process of work, the tape does not sag, but processes the wood without the occurrence of a large frictional force. This design can be used when machining long workpieces..
- The disc unit, or as it is also called a disc grinder, is equipped with an axis to which the abrasive wheel is attached. During operation, the disc begins to rotate around its axis. In the process of work, you can adjust the speed of the wheel with an abrasive coating without reducing the speed of the axis itself.
- The drum machine is designed in such a way that abrasive belts are wound in a spiral on adjacent rollers. In turn, these elements are distant at a certain distance from a flat surface (table top). By adjusting this distance, you can calibrate wooden parts.
There are other types of portable grinders as well. Often, drills and screwdrivers are equipped with special nozzles with abrasive spraying..
The device and principle of operation in each version is different from each other. Moreover, wood will be processed in different ways..
The easiest way to create a disc sander. But a do-it-yourself grinding and grinding machine, based on a belt design, will be much more functional and in demand in a home workshop than any other.
Step-by-step manufacturing instructions
Initially, you need to prepare a drawing of a grinding machine for wood with your own hands. Without a basic sketch, it will not work to create a fully functional machine. The drawing must be accurate – all parameters and dimensions must be indicated. An example of such a drawing:
First, it is worth calculating the motor power, which will be enough for work. This can be done using the following formula:
Explanation of the designations used in this formula:
q is the pressure of the area of a wooden part on the plane of the canvas (N for each square centimeter).
S – the area of the part that interacts with the abrasive, measured in cm².
K is the index of the working part of the abrasive relative to the part. This takes into account the density of the wood fibers and the grit size of the abrasive. Indicators can fluctuate within 0.2-0.6.
k – coefficient of friction of the seamy part of the abrasive on the working surface.
U – the speed of rotation of the abrasive belt (m / s).
n – efficiency of the entire system.
If you calculate all these indicators and correctly build a drawing, then you can get an effective and functional homemade grinding machine. To make a grinding machine with your own hands, it is worth choosing the necessary tools and materials, deciding how and under what conditions the device will be used.
How to make a belt sander
Grinder is a belt sander for universal use (sanding wood, metal, carbon fiber) has a small size and functional design, which is easy to transport if necessary.
It is quite simple to make such belt grinders with your own hands, working according to the following algorithm:
- Initially, you need to prepare a drawing for the tape emery with your own hands. In it, you need to work out all the parameters as accurately as possible and specify the dimensions. In this case, it is worth considering what functions the device will most often perform..
- After creating a detailed and understandable drawing, it is worth preparing all the necessary tools and materials for work: chipboard (metal), screws, bolts and nuts, propylene pipes, bearings and a building corner. An important step will be precisely the choice of a suitable engine, which should have a power of no more than 1 kW and operate from a 220 V. If the motor does not correspond to the parameters, then this can significantly aggravate the principle of using the device as a whole. The most suitable option is a motor from an old washing machine..
- The main body is made of chipboard or metal, which will correspond to the parameters specified in the drawing by its design. The motor is fastened to the base with bolts and nuts, and the construction angle is also attached. It is the last element that will be the limiter for the tape..
- Next, rollers are formed under the tape, you need to insert a polypropylene pipe with a diameter of 20 mm into a pipe with a diameter of 32 and additionally insert a tin tube into a smaller base for more reliable fixation. Put the structure on the spline part of the motor. According to the same principle, but using bearings, the driven shaft is assembled.
- The last step is to attach the abrasive belt..
The wood sander can now be used by plugging it into a regular socket. If you make a metal case, you get something like this:
To further simplify the manufacturing principle (make only the body) of the belt model, you can use a drill, screwdriver or angle grinder. To use an angle grinder for sanding wood, you do not need to make a frame to which the tool will be mounted. But the drill must be fixed in the case at least made of wood. Such constructions will look like this:
Making grinding machines of various designs and capacities at home is not difficult. It is enough to build an accurate and correct drawing, choose the right engine and build a base structure for attaching the abrasive elements. As a result, such a device will become simply irreplaceable when working with wooden parts. The functionality of such devices is slightly different from the factory models, but this characteristic is compensated by the efficiency and simplicity of the design (availability) of the device..
Working in a home workshop, I often thought about the need for a special grinding machine, which will be in demand when processing the edges of wooden balusters, handles and other furniture parts. Such equipment will be useful both for finishing cleaning of various steel surfaces, and for polishing the blades of kitchen knives. Even with the restoration of a bronze samovar faucet, such an assistant will not be superfluous. If you have one, you do not need to sand by hand, polish or clean something by clamping the brushes in the chuck of a drilling machine or drill.
Homemade grinding machine: 1 – support; 2 – rack (4 pcs.); 3 – spacer plate (8 pcs.); 4 – shaft assembly; 5 – cheek (2 pcs.); 6 – electric drive assembly; 7 – area of the site; 8 – platform assembly Chuck adapter (1 pc.) Nut (1 pc.) Nut (left thread, 1 pc.) Pulley bushing (1 pc.) Spacer bushing (1 pc.) Bushing for sanding stone (1 pc.) Shaft (1 pc.)
Pressure washers (2 sets) Arbor for felt and rubber (2 pcs.) Shaft with working tools: 1 – left polishing chuck on a rubber base; 2 – felt disc; 3 – plywood disc with sandpaper; 4 – the right cartridge for a petal disc
On the shaft with a disk cutter, I cut the flats on a turnkey basis and assembled it, putting on a pulley, a spacer sleeve and two housings with bearings.
The flats on the shaft are machined with a disc cutter
I bought a 380 V electric motor with a power of 0.37 kW at 950 rpm at a flea market. After lowering on the pulleys, the motor should give the shaft 600 rpm.
Well, then everything turned out to be easier than I thought. From two corners and a pair of steel cheek plates I welded a platform for fastening the bearing housings. Marked and drilled four holes with a diameter of 11 mm. Then I cut out the base plate from sheet steel 10 mm thick, making four holes with a diameter of 12 mm in it at the corners. Using chalk markings, I welded four vertical posts from a 35 × 35 mm corner to the slab.
On top of the corners I set and welded the finished platform. After checking the vertical and horizontal lines, I welded everything completely. I added spacer plates for frame rigidity and cleaned out all welds. Then I painted the finished frame green, and the bearing housings yellow.
When installing the shaft assembly, I put a V-belt over the frame. I cut the protruding edges on the support platform of the end mount of the engine. I tried on the engine in place to the frame with a belt on the drive pulley. With a sharp scribe, he marked the centers of the mounting holes and removed the engine. On the basis of the outline, he specified the tension grooves, drilled, cut off, cleaned … And put the drive motor in place, pulled the V-belt, secured the position by tightening four M10 bolts with nuts and washers. After completing the assembly, he transferred the machine to a prepared place by the window on which window hinges from TBM-Market were used, and attached it to the concrete floor.
It remains to install a protective cover over the driven pulley, the starting machine and supply 380 V to it with a 4 × 0.75 mm 2 cable.
The right chuck is fitted with a flap disc … … and the left chuck is fitted with a polishing wheel with a rubber base
As a working tool on the right side, I put a plywood disc with a diameter of 220 mm with coarse and fine sandpaper glued to it. I clamped a flap wheel in the right chuck. On the left side there is a felt disc with a diameter of 160 mm and a width of 50 mm, made of gray felt boots, and in the cartridge – a polishing wheel on a rubber base with a diameter of 120 mm. Over time, there will be other tools: a cutting disc, diamond and rubber, a set of sharpening stones on a leg and a small felt circle on a leg.
Fastening the machine to the workshop floor
Already from the next day after the trial run, the new machine did not stand idle. He helped make new oak handles for the old charcoal iron. During the restoration of the knife, he removed the rust from the blade with a petal circle and processed the wooden handle with “sandpaper” of a large circle. It’s good that I have such an assistant.!