Grinder head on the angle grinder with your own hands

Homemade Grinder. Important points.

There are many designs of homemade grinders. Someone makes them using the motor from an old washing machine, someone makes from an old angle grinder or drill, but all these models are united by the same technical details. Let’s break them down in more detail.

Some specific sizes are the same for all grinders does not exist, they can be purely individual in each case. When choosing the size and design of the belt-sanding machine it is necessary to be guided by the free space in your workshop and the rule, the longer the belt, the more resistant to abrasion it will be and, accordingly, less often it must be replaced. If you are going to buy pre-bonded bands for the grinder, then the machine must be designed with the size of these bands in mind. If you are going to glue the tapes yourself, then the size of the machine can be arbitrary, but it is best to stick to the standard sizes of the tapes.

Abrasive belts for grinder width come in two sizes: 50 and 100 m. The length of such belts can be 610, 915, 1230, 1600, 1800, 2000 millimeters.

It is best if you have the abrasive tape of necessary length, then it will be easier to adjust the size of the grinder for it.

The main components of the grinder are the machine frame with the turntable and belt clamping, motor with drive roller, tensioning roller, barrel roller and, if necessary, additional driven rollers. Barrel roller can be simultaneously a tensioning roller.

The most compact Grinder can be made with only two rollers, one driven on the motor shaft and the other tensioned barrel-shaped.

Grinder. belt grinding machine

Belt grinding machine with washing machine motor.

Same machine with washing machine motor. View from another angle.

The machine is built with a plywood frame.

Grinder.

Grinder with furniture gas spring.

This machine is made with rollers from car timing system.

Another belt grinding machine with plywood frame.

Grinder with angle grinder motor.

Compact machine with furniture gas buffer.

Compact belt grinding machine on two rollers.

Machine with plywood frame.

If the Grinder is to be used with long abrasive belts, then it cannot do without additional driven rollers.

Why a barrel-shaped roller?? Nearly impossible to keep all castors perfectly parallel to each other when setting up the machine. The belt tends to come off the rollers for this reason. To eliminate this disadvantage, a barrel roller is used. By adjusting the tilt of its axis, it is possible to “force” the abrasive belt to stay in place.

To adjust the barrel roller axis, you can use the principle of an ordinary door hinge. The axis of the roller is welded to the moving part of the hinge, and the adjustment is made with a bolt. Which rests on the moving part of the hinge.

The picture shows the barrel roller of a grinder.

Note barrel roller and adjusting bolt.

Barrel roller with adjustment mechanism.

Barrel roller grinder.

The abrasive belt tensioning mechanism can be made in several ways. The most common is by means of a spring, the second is by means of a furniture gas shock absorber, and the third is by means of ordinary rubber, such as from a bicycle camera. If a furniture gas shock absorber will be used, you should know that it does not work well at low temperatures.

It is recommended to make the belt stop in two layers. The base of the stop should be made of metal sheet and glued to it a smooth porcelain tile. That way the stop will be practically not heated during the intensive work on the grinder. Also porcelain tile wears much slower than metal. It can be easily replaced as it wears, you just need to warm up the joint with a construction dryer and it will come off. It can be glued on the usual silicone sealant for marble, such as Silirub MA from Soudal.

The stop must be adjustable in relation to the belt. It must be moved tangentially to the belt, or at a slight offset of 0.5 mm. This overhang does not cause excessive belt wear, but allows longitudinal grinding of long strips and prevents them from snagging on the convex parts of the rollers.

How to calculate the drive roller diameter.

To calculate the diameter of the drive roller, you need to know the speed of the belt with which the Grinder will work and the number of engine revolutions.

The belt speed should be chosen according to the belt manufacturer’s recommendations. For example, for 3M Cubitron steel belt a speed of 22-25 m/s is recommended, for aluminum zirconate belts a speed of 30-35 m/s is recommended by the same manufacturer. The belt speed depends not only on the type of abrasive, but also on the grit size. And so on the average it is recommended on carbon steel 32. 38 m/s, alloyed and stainless steel 18-30 m/s, Titanium.15 m/sec, non-ferrous metals 35-45 m/sec, plastics 10-30 m/sec, malleable iron 38-34 m/sec, gray iron 35-45. As for the wood, it is recommended not to exceed 20 m/sec. You also need to know that different wood will burn at different speeds.

The formula for calculating the speed of the belt:

where D-diameter of the drive wheel in mm, N-rpm.

The formula for calculating the diameter of the drive roller:

Where V is the speed of the belt in m/s. N-turns per minute.

Example calculation. You need to calculate the diameter of driving roller for steel processing (22-25 m/sec). Electric motor 2800 rpm.

The speed of the belt for different materials can be adjusted by changing the diameter of the drive roller or by adjusting the speed of the motor. Also, it should be understood that as the diameter of the drive roller increases, the load on the motor increases and if it is small capacity, such as from a washing machine, it will often stop even from a small load.

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What you need to make a mini grinder

Described today attachment for angle grinder turns angle grinder into a mobile Grinder, which allows you to perform operations with small parts. It will require a minimum of material to make:

  • strip of metal with a thickness of 4 mm;
  • Profile pipes with sides 15×15 and 20×20 mm;
  • bearing (inner diameter of 8 mm);
  • high nut with 14 mm thread.

The tool will become clear in the course of the article. The only thing you can say is that you can find everything in almost any garage.

Making the base for the nozzle on the angle grinder

The main task in the first step is to properly bend a strip of metal. It must fit the diameter of the angle grinder, namely to take the place of the handle clamp.

It can be bent to the desired shape using any suitable pipe. However, the ring must not completely encircle the circumference. You need a place for the profile pipe that will be welded to it afterwards. How everything should look before the welding stage, you can see in the photo-example.

Angle grinder clamp on profile tube

However, it is not possible to clamp such a ring on the circumference, which means that it is necessary to make some kind of a clamp. To do this, you need to drill through the profile tube in the area of the welded steel ring. Next, we make notches (one along and one across the profile pipe). It may be difficult to understand the location of these cuts in the text, so let’s show by example.

Now it remains to make a thread on one side of the kerf, and expand the second hole. It turns out that when screwing the bolt into the thread, it can reduce the circumference of the clamp by the width of the saw. At this stage it is worth checking whether the clamp is well clamped. If the design is loose, you should increase the width of the kerf.

Longitudinal tube and its purpose

The cross tube is ready, but now you need to weld a longitudinal tube to it, which will support the sandpaper belt. It should run exactly in the middle of the guide pulley (we’ll talk about making it later).

After the longitudinal profile tube is welded in place, you can cut off the excess, plug the hole from the end and deburr all the seams. This will make the product look much neater.

Principle of the grinder design and principle of its work

In order to properly understand the design and principle of operation of the grinder, let’s look at its construction. The main task is to find a powerful motor, which must be equipped with a drive.

Important! The torque is transmitted to the rollers, which set the grinding belt in motion.

So, the main elements of the grinder, in addition to the motor, are:

  • Straight roller with a pulley.
  • Tension rollers.
  • Abrasive belt.
  • Base.
  • Device for tensioning the belt and rollers.
  • Table for clamping the workpiece (some models can be equipped with a turntable).

Once the machine is plugged in, the rollers set the grinding belt in motion. over, the position of the rollers can be shifted to control the tension of the abrasive belt.

In some cases, the table can rotate by 180 °

When assembling the grinder yourself, it is important to position the rollers strictly perpendicular to each other to prevent the belt from tilting, which can lead to belt breakage.

Tip! Before deciding on the size of the belt and width of rollers, think about what surfaces you plan to work, their dimensions and the volume of work.

The choice of the belt determines the speed and quality of machining. Most often in machines of this type the following belt sizes are used: 610, 915, 1230, 1600, 1830 mm in length, in width there are only two options. 50 and 100 mm. Bottom blade must be elastic.

Fabric backing withstands surface tension better

Grinder “by Chapay”. a brief overview

Andrei Chapay has developed his own version of the Grinder. The model is so beloved by craftsmen that its name soon became a nickname. Handyman even developed a whole line for the trimmer units, which are now dispersed to workshops around the world.

Grinder “by Chapay” is a universal machine with a turntable that allows to work on different surfaces

For your information! The most common models of grinders: “HF-10”, “HF-12”, “HF-16” (professional series), as well as new mobile versions of 610 series grinders “HF610-63” and “HF610-71”. are made with zinc coating.

Additionally included is a disk. It is installed in place of the main roller for sharpening knives and removing rust. One of the most popular grinder models. it is made on a reinforced swivel base. The frame is equipped with two uprights. The base for the frame are two metal sheets 12 mm thick.

The price of such a sample can not be cheap. Approximate

Materials, Accessories and Tools

At the preparatory stage you need to prepare everything you need to make a grinder:

  • Circular saw. It can be replaced with a homemade sawing machine, made from an electric jigsaw.
  • Milling and drilling machine.
  • Pliers, screwdriver set, marking tools.
  • Vacuum cleaner for thorough cleaning of parts.
  • Thick plywood (at least 20 mm).
  • Fixing elements.
  • Tape for the future grinder.
  • Lacquer.
  • Closed bearings.

If you already have all this, let’s start the production of the machine. It should consist of the following structural elements:

  • angle grinder, on the shaft of which the leading roller is installed;
  • A solid base on which to move the workpiece;
  • movable bracket to adjust the position of the angle grinder and its movement on the base;
  • two driven rollers.

Grinders by Chapay

There are now many belt sanding tool designs available. Some are more successful, others are too complex to implement.

Designs of grinders by Chapay are recognized as successful. The developer offers professional tools and versions for home workshops. An essential advantage of these models is the large range of changing machining angles. The original design of the turntable was created for this purpose. To expand the capabilities, the devices are equipped with special disk fasteners. The pivoting frame made of two 12 mm thick sheet metal plates provides high tool reliability.

In addition to professional units, Chapay has developed mobile versions (GCh610-63 and GCh610-71). They are convenient in operation and have good consumer characteristics.

Design features of the grinder with their own hands: photo

It is recommended to take into account all the nuances of the design of the factory units. This makes it possible to make the most efficient table grinding machine. The standard equipment of this type of machine includes a support table. In addition to its main purpose, this surface performs another auxiliary function: it is used to fix the workpiece to be processed.

In factory machines, such a table can rotate relative to one axis. The angle of rotation, as a rule, is 90°. It makes it possible to grind two planes of the workpiece (located perpendicularly) without changing the position of the part fixed on the rotary surface. When assembling a simple grinder with your own hands, you can make a static table. This will greatly simplify the assembly, but the finished unit will have less functionality.

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There are other, no less important parts that are included in the construction of such machines. Let’s consider what other constructive elements should necessarily have any Grinder, used for grinding workpieces made of different materials:

The main task in the manufacture of the grinder. to find a powerful motor, which will need to be equipped with a drive

All these parts are quite easy to make with your own hands. Belt grinder during operation can produce dust or sparks. It depends on the material of the part processed on such a machine. Because of this, experienced craftsmen strongly recommend using special glasses. In addition, it is recommended to arrange a protective wall, for the manufacture of which acrylic glass is used.

Portable units come with a housing made of steel. The grinder’s stand must have holes, which are necessary for fixation of the machine on a wooden surface (by means of screws). When choosing a belt, note that its length depends on the power of the machine (and vice versa). The higher the index, the more powerful the drive must be, respectively.

Safety precautions

When working with a homemade grinder should not neglect safety precautions and personal protective equipment. Should not be allowed to work under 18 years of age. Always use protective glasses and earplugs to protect your eyes and ears against harmful external factors. Also wear a mask to protect the respiratory system from dust.

In the video, shown below, you can learn in detail how and from what to make a device for grinding. It also gives all the basic dimensions of the machine’s parts.

Grinding machine from the angle grinder

Angle grinder is convenient as a drive by its design feature. It is enough to make a metal base for rollers, to tension the tape, and to fit the dimensions of the leading roller under the guiding SCHMU, and the machine is ready. To see in more detail the drawings of the grinder, made with their own hands at home from the angle grinder, you can see in this photo.

Also on sale in tool stores you can find ready-made attachments for angle grinder.

How to make rollers for the grinder with your own hands

Preparation of rollers for the grinder is one of the most time-consuming stages of work. Most often for grinder make four rollers with different sizes. from 70 to 150 mm. Most often metal is used in the work, in the first case steel is used, titanium or duralumin is best suited. And the width of the rollers depends on the size of the sanding belt.Many craftsmen use both metal structures and wooden ones, the main thing is to ensure the quality of attachment of the “barrel” to the working surface.

Drawing of the roller for the grinder with dimensions

When creating a drawing for making the rollers, remember that the rollers should be barrel-shaped, this will all ensure that the belt is held. The drawing is a prerequisite for the work, because, most likely, you will have to go to turners. If you want your machine to work well, you should not skimp on it, and you should choose bearings of class 6 or higher.

The pulley for the grinder with their own hands

The pulley for the grinder after the motor itself is one of the most costly elements of the grinder. The finished part costs at least 2,000.

Options for metal pulley and rollers

How to make rollers for the grinder with their own hands

Preparation of rollers for the grinder is one of the most labor-intensive stages of work. Most often for the grinder make four rollers with different sizes. from 70 to 150 mm. Most often metal is used in the work, in the first case steel is used, titanium or duralumin is best suited. The width of the rollers depends on the size of the belt.Many craftsmen use both metal and wooden designs, the main thing is to ensure the quality of fixing the “keg” to the work surface.

Drawing for a grinder roller with dimensions

When creating a drawing for making rollers, remember that the rollers should be barrel-shaped, this will ensure that the belt. The drawing is a must, because you will probably have to use a turner. If you want your device to work qualitatively, it is worth not saving on this, in addition, you should choose bearings of class 6 or higher.

Grinder pulley with your own hands

The grinder pulley, after the motor itself, is one of the most costly elements of the grinder. The finished piece costs at least 2,000.

Metal pulley and pulley options

Making the belt

For self-gluing the belt will need glue, sandpaper of two “adjacent” types in terms of grit, and a piece of cloth.

It is necessary to cut the grittier sandpaper into strips of the desired length and width. Then grind the abrasive layer on both sides for 2-3 cm. Glue a piece of cloth to the stripped edges and let dry. We cut the “patch” from finer sandpaper and glue it on the cloth.

Grinder with minimum investment

What to make the drive for the grinder from

The drive is the most important part of any machine. It is very important to choose the right motor for the machine. Grinder requires a motor of one and a half to three thousand revolutions per minute, power from 0.75 kW.

You can use high-power motors, a kilowatt or more, but there is a risk that the sandpaper will tear

The power of the motor determines the performance of the appliance. Very handy, if there is a possibility of manual adjustment of the drive, for tasks of various kinds. Proceeding to the manufacture of a simple grinder with their own hands, rummage through the junk in a garage or shed: probably there are suitable motors from units that have served their time.

Is it necessary to make the self-made Grinder with the engine from the washing machine?

Let’s start with the controversial issue of making a grinder with their own hands on the basis of the motor from the washing machine. It is controversial for one simple reason: during the work on the device a lot of dust and shavings, particles of paint and other waste is formed. They get clogged in the holes of the motor from a washing machine, and the construction quickly fails. But, nevertheless, some craftsmen have such units, and they work successfully. An example of such a device in this video:

Step-by-step recommendations on how to make a Grinder from a drill

Drill. a must-have tool in every home. Often something in it breaks, the housing or the armature, or maybe a new, more powerful and convenient model just comes out, so that the old one gathers dust somewhere in a box in the garage.

Using a drill drive, you can build a pretty powerful Grinder

How to do it in practice. let’s break down the process in detail in the photo and video instructions:

Grinder from an angle grinder with your own hands: drawings and ready-made attachments

Angle grinder, or in common parlance angular grinder. practically a ready-made basis for LSM. On its basis, the machine is assembled according to the same algorithm as the above device from a drill. The scheme is as follows:

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As a result, you will get a mini-grinder, made by your own hands, which will sharpen knives and scissors. There is an option not to bother with self-made, and buy the factory nozzle. It is attached to the angle grinder with the bracket. To find such a device is not easy, but in our age of Internet commerce nothing is impossible. Such a gadget is convenient because it is possible to use a working angle grinder, not breaking the design of the serviceable device in principle.

Such Grinder is suitable for smoothing seams after welding. For other works you will need to think about a stationary attachment

How to make a Grinder from a grinder with your own handsInstruction

Another uncomplicated variant of homemade LShM. from an ordinary grinder. Almost all you need to do is to fix the device on the workbench and adjust the system for turning it on and off. Read more about it in the video.

How to make a Grinder with your own hands: drawings with dimensions from different authors

Each craftsman brings something different to the design, so before you take on making a grinder grinder with your own hands, explore the options. Here are some blueprints for example:

How to glue the tape for the grinder with their own hands and special requirements for it

Developing a homemade Grinder with their own hands, it is better to provide for the use of a belt of standard-sized emery board. Standard dimensions are length 1830, 1600, 1230, 915 and 610 mm and width 100 and 50 mm. Then you will not have to puzzle over how to make a grinder belt with your own hands. The belt, homemade or factory-made, must meet the following requirements:

  • an elastic base of fabric;
  • High ability to withstand angular speeds;
  • abrasion resistance;
  • the possibility of lengthening it without violating its integrity by 10-15%;
  • Minimize heat when working for extended periods of time.

Tip! Do not use belts longer than 1230 mm for your self-made tool, because you have to increase the size of the construction, and this imposes additional requirements on its placement.

When making your own ribbon, try not to make more than one joint. All glue points stretch during the sanding process, and the tape loosens

  • Cut a strip of sandpaper of the desired length and width from a sheet of sandpaper. the edges of the tape make a slanting cut.
  • Tape the edges together and pre-glue them to the abrasive side with painter’s tape.
  • Secure the cut with a few drops of superglue.
  • Apply glue to the cut and a piece of silk ribbon, press the surfaces together.
  • Wrap the gluing place with paper and fix it with a press overnight.

The fabrication process

Sheet metal thickness of 10 mm must be used for the power parts of the machine. To draw the contours of such parts for further cutting, you can refer to the drawing. There is no need to accurately observe the dimensions, because they will depend only on the size of parts that you are going to process on the belt grinder. You can draw the contours of the parts on a sheet of metal with a marker, and use an angle grinder and an electric jigsaw to cut them out. It is much easier to cut such parts with a plasma torch, but not everyone has such equipment at home.

Read also: Tungsten electrode sharpener

Base, machine housing parts and motor before assembly

To make the base of your homemade grinder more solid, it is better to use a sheet of metal 12 mm thick for its manufacture. To assemble the base of the grinder you can use screw joints, but then you have to drill a lot of holes, which will greatly weaken the entire construction. It will be much easier and safer to assemble the base of your machine with electric welding.

A lot of time will be needed for the semicircular grooves on the parts of the belt grinder, which provide rotation of the platform on which the rollers are placed. To make such grooves yourself, you will need to tinker with a drill, burrs and a file, as well as use a drilling machine. You can make it a lot easier on yourself if you entrust a qualified miller to make these grooves.

Layout of a machine made of plastic: thanks to the swivel unit, the Grinder can be in an upright position.

To make the rollers of your homemade mini-machine, it is best to use titanium or duralumin (D16). If you can not find blanks made of these materials, you can use steel, but then the rollers should be as light as possible, choosing the metal from their insides. To make the rollers of a homemade machine you will need the help of a qualified turner, just take care to prepare a drawing for him.

The largest roller band grinder, which will be fixed to the shaft of the motor, in any case will need to make steel, as titanium dummy of such a diameter is very difficult to find, and duralumin may not withstand significant loads. For the whole homemade machine you will need to make 4 rollers, whose dimensions (diameter) are: drive roller. 150 mm, tensioner. 100 mm, two small. 70 mm. If you are going to make a mini-machine, the diameters of the rollers can be smaller.

When you assemble your homemade machine with finished rollers, it is very important that they are positioned strictly in one line. Otherwise you will be constantly confronted with slipping of the belt. The width of the rollers depends on the size of the sanding belt you are going to use on your equipment. When you will make a drawing for the manufacture of pulleys, then be sure to take into account that they should have a barrel-shaped shape, this will ensure a reliable retention of the grinding belt on them in the process of work. In order to give the rollers this shape, a slight bevel is made at each edge of them: 1-2 mm.

The finished rollers of your homemade belt grinder should have a smooth surface, this should be told to the turner, who will make them. The bearings on which they will rotate, should only be of the closed type, otherwise they will quickly be clogged with dust generated during the grinding machine. To keep your homemade equipment running long and smoothly, you need to choose bearings with at least class 6. The rollers of the grinding machine rotate at high frequency, so the bearings for them must be of very high quality.