Belt grinding machines allow you to remove the effects of corrosion, paint residues, and carry out the operation of grinding surfaces made of various materials (metallic and non-metallic structures). The element for carrying out such work is a sanding belt. Manufacturers offer a wide range of such products. The belt for the grinder is selected based on the requirements for solving the tasks, the quality of processing, and the type of material being processed.
Types of grinder belts
Sanding belts for grinders are classified according to the following indicators:
- purpose (type of operation performed, quality of processing);
- geometric parameters (length and width);
- permissible speed;
- type of abrasive;
- method of applying an abrasive coating;
- the company producing such products;
- cost.
Based on the type of operations performed, grinder products are divided into four categories:
- pre-processing (creation of finished forms or blanks);
- rough surface treatment;
- preparatory operation before final grinding;
- fine or final polishing.
Each operation uses its own sanding belt. The solution to the first problem is carried out using a rough (stripping) tape of grade P24. For roughing, smaller grades P36 are used. Preparatory operations are carried out on P80–P120 belts. Finishing is carried out using belts of the smallest abrasive. For this purpose, diamond tapes of grades A3k0–A100 can be used.
The permissible speed of movement of the grinder belt is determined by the substrate material and the strength of the entire structure. A durable fabric or synthetic fiber-guided base is used as a substrate.
Based on the type of sanding material and the method of its application, the abrasive belt is divided into categories.
VIEW Grinding belts on AliExpress → The following is applied to the surface as abrasive chips:
- natural stone (for example, silicon carbide or garnet);
- ceramic chips;
- alumina;
- diamond chips.
It is applied to the surface in two ways: open or closed. Each of them provides a certain degree of coverage of the substrate. The first applies abrasive to no more than 60% of the surface of the abrasive material. The second provides full coverage.
The geometric dimensions of the grinder abrasive belt depend on the technical characteristics of the grinding machine. The main parameters are length and width. All of them are standardized and have several established sizes. They are available in two widths: 50 and 100 millimeters. Length is a more variable value and is equal to 610, 915, 1230, 1600, 1800 millimeters. For some specialized machines, a belt of a given size is produced: 2000 mm with a width of 50 mm.
Depending on the characteristics, a choice is made for processing wood, metal, and polymer surfaces. In some cases, sanding tape is used to polish the surface.
Ready-made attachment for angle grinder
The simplest thing is to purchase a ready-made grinding device and mount it on an angle grinder. The photograph shows that installation of the mechanism does not present any particular difficulties. It is enough to attach the bracket with rollers to the angle grinder, having first removed the protective casing. The drive wheel is fixed to the angle grinder shaft. Sanding paper is put on the rollers, and the sanding machine is ready for use.
However, such a device cannot always be bought in a store, and the cost of such a gadget is significant.
An attachment consisting of a rod with two rollers allows you to reduce costs, but at the same time limit the possibilities of using the grinder. The device allows you to make a grinder from an angle grinder in a matter of minutes. The device has a standard mount suitable for mounting on an angle grinder.
The design of such a mechanism is intended for cleaning welding seams. Polishing wooden products with such a gadget is quite difficult. However, if it is rigidly mounted on a table, it can be successfully used as a sharpening machine for straightening cutting tools or sharpening knives, axes, etc.
What you should know when choosing a tape
To obtain good polishing quality, it is necessary to navigate the grinder parameters, equipment characteristics and features of the surface being processed. When selecting a sample, it is necessary to analyze the following parameters:
- what type of product is needed (coarse, medium, fine or diamond abrasive);
- calculate the belt speed (it must withstand a shaft rotation speed of more than 1500 rpm);
- determine what abrasive resistance the selected specimen has;
- find out the value of the maximum permissible elongation and tensile strength (products with an indicator of at least 15% are considered good);
- on what basis the abrasive is applied (by what method and its composition);
- use the marking to determine the length of the tape;
- whether the width of the belt suits the dimensions of the machine used.
Calculation of parameters and assessment of the main characteristics of the grinder must be made before purchasing the product. This will get rid of problems that may arise when replacing it or using it incorrectly.
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Safety precautions
When working with a homemade grinder, you should not neglect safety precautions and personal protective equipment. Persons under 18 years of age should not be allowed to work. When using the device, be sure to use safety glasses and earplugs to protect your vision and hearing from the harmful effects of external factors. We should not forget about a mask that protects the respiratory system from dust.
In the video below, you can study in detail how and what to make a grinding device from. It also gives all the main dimensions of the parts of the mechanism.
How to glue tape with your own hands
The retail chain sells various abrasives ready-to-use. They can be in rolls or already glued to a specific size. However, it is not always possible to find the required copy. Sometimes it becomes necessary to replace a failed tape during operation with a serviceable one. In these cases, the abrasive strip is made independently. This is a simple process, but requires knowledge of the gluing procedure, the availability of appropriate glue and accuracy. To solve this problem you will need:
- tape for gluing abrasive materials;
- glue (the choice is quite wide: from specialized to universal);
- degreasing liquid (gasoline or white spirit);
- a clamp or weight for compressing the glued parts while the glue dries.
Gluing is carried out in several stages:
- Mark a strip of abrasive for the grinder along its length. It should be noted that to make the connection stronger, the joint of the strip is glued at an angle. The angle of inclination may vary. The larger it is, the longer the contact length.
- Cut out the backing. Its length depends on the selected material. It determines the reliability of gluing.
- Degrease all surfaces that are planned to be glued. The quality of processing affects the final result.
- Gently press the substrate and parts of the abrasive strip. It is advisable to place the joint under a press or use a clamp. If this is not possible, use any load.
- After completion of the work, the structure is left under load for several hours. The required time, procedure and rules for working with a specific glue sample are given in the instructions or written on the packaging.
If gluing is carried out carefully, a homemade strip will last no less than a product manufactured at a specialized enterprise.
Grinding machines of this class have wide capabilities. For a more complete analysis of their application, it is advisable to generalize the experience of a large number of users. Share your opinion in the comments, this will reveal additional grinder opportunities.
Rotary table device
The rotating attachment for the grinder is rather a luxury, but a nice one. Such a system will greatly expand the functionality of the machine and make it easier to work with complex parts. The purpose of such a rotating mechanism is to change the axis of the working surface, in other words, the plane on which sharpening takes place. Very often you can find a rotary table mechanism like this, not very easy to implement, but understandable.
Rotary beds or grinder tables are not used in many homemade models; this is the prerogative of professional machines designed to solve several problems
As we have already noted, a professional grinding machine is not a cheap pleasure. However, if you professionally want to provide services related to the use of mechanisms, then you will have to consider ready-made options for machines. Such solutions are quite universal and, with proper patience and skill, can pay for themselves. Let's take a brief look at some of the models that are currently popular. Prices for professional and semi-professional units vary from 45,000 rubles to 130,000 rubles.
Grinder "Lefty"
Characteristics: motor – 1.5 kW, belt length – 1250 mm (up to 1600 mm); The model is interesting for its ability to use additional equipment (wheel, contour), which is included in the kit.
Grinder-sharpener “Kraton” BG 14-05
Characteristics: the device is used for sharpening metal tools and wooden parts; power consumption – 2 kW, movement of the sanding cloth – 14 m/s; disc diameter – 150 mm; tape width – 50 mm; Features: rigid cast base, adjustable stops and protective screen.
Grinding machine BISON ZShS-330
Characteristics: machine type - disc-and-belt; circle – 125 mm; speed – 2950 rpm; tape size 762×25 mm; power - 330 W; belt speed – 810 m/min.
Sharpener METABO BS 175
Characteristics: sharpener type - with grinding. tape; circle - 175×25×32 mm; circle diameter - 175 mm; circle thickness - 25 mm; landing diameter -32 mm; speed – 2980 rpm; power - 500 W.
Grinder GRIT GIS 150
Characteristics: rated power consumption - 4 kW; voltage/current type at 50 Hz - 3×400 V(3~); voltage/current type at 60 Hz - 3×440 V(3~); Idle speed at 50 Hz - 3,000 rpm; Idle speed at 60 Hz - 3450 rpm; tape dimensions - 150×2000 mm; weight - 93 kg.
And if you still decide to assemble the grinder yourself, we recommend studying several solutions, including in open Internet sources. The fact is that many ideas were created by their inventors for a specific type of work, which means they may not be suitable for solving your problem. Many grinder parts can be purchased ready-made. For example, rollers can be purchased separately or ordered from professional craftsmen. Don’t forget that the main goal is not so much the ability to save on assembling a particular unit, but to simplify the work and make it as safe as possible.
