Grinding machine for plaster: features and operating principle

In order to complete wall finishing projects with smooth, even surfaces, a plaster grinding machine is a necessary tool. The quality of your plastering job can be greatly enhanced by knowing how this equipment operates, regardless of whether you’re a professional or a do-it-yourself enthusiast.

The salient characteristics and basic principles of plaster grinding machines will be discussed in this article. Gaining knowledge of these elements will make it easier for you to select the best tool and apply it efficiently for your particular requirements.

Plaster grinding machines are a necessary tool that make the process of leveling and smoothing plastered surfaces easier and faster while maintaining a high-quality finish. Its primary advantage is its capacity to sand big areas quickly and accurately while applying constant pressure, which also helps to cut down on manual labor. Users can achieve professional results with minimal effort by understanding its operating principle, which involves rotating discs or belts that grind the plaster evenly.

The device of grinding machines

An electric drive powers the plastering machine.

• Built-in machine, previously produced, and now conservation stocks are used:

1. single-disk – SO-112B;
2. double-disk – SO-86B, with internal and external disks.

• With a drive for rotation of the grinding disk by means of a flexible shaft.

The plastering and grinding machine in this instance is linked to the external network:

• With alternating current with a frequency of 50 Hz by means of a frequency converter and a voltage of 220/380 V.
• Through three-phase asynchronous electric motors with a squirrel-cage rotor, the operation of which is carried out with a high-frequency current of 200 Hz and a voltage of 42 V. Such low voltage is electrically safe for the operator.

The devices have an electric cable with a plug that connects it to the power source.

The photo below the letter "a" displays the single-disc plastering and grinding machine SO-112B. It features:

• Grinding disc. It is made of foam plastic or chipboard.
• The disc is driven by an electric motor.
• The output shaft of the gearbox is connected to the disc by an elastic rubber suspension.
• The elastic flexible connection allows the disc to install itself on the surface being treated, regardless of the position of the machine body, which reduces the resistance of the disc to rotation during grouting.

Plastering and grouting machine SO-86B with two discs beneath the letter "b" Within this apparatus:

• A two-stage gearbox from the electric motor provides separate drive of the inner and outer grouting discs rotating in opposite directions.
• Both discs are rigidly connected to the output shafts of the gearbox.
• When the inner and outer discs rotate, the resultant of their moments is zero. This makes the machine more stable, reduces the load on the operator"s hands, which increases labor productivity and improves the quality of work.

Advice: Water must be supplied to the machines so that the surface being grouted is wetted, as this will enhance the quality of the grouting. Water is delivered to the treated area at a pressure of 10–30 kPa; the water supply switch controls the volume of water, which is dependent on the surface condition.

• Water is supplied to the machines from the water supply through a rubber hose.
• The drive switch and water supply switch are installed near the right control handle.

What is the principle of operation of the machines

When the gadget is powered on:

• Torque is transmitted from the motor rotor shaft to one of the gears of the reducer located on the gear shaft.
• One gear enters into internal engagement with the outer disk.
• The second engages with the gear, which causes the disk located inside to rotate.
• The grouting disks rotate in different directions. This causes the plaster mortar to be leveled and rubbed.
• Water is supplied to the grinding discs to improve the quality of the surface.

The leveled compositions are ground and leveled when the grinding disc on the carrier disc rotates over the surface to be processed.

Advice: You can easily grind both vertical and horizontal surfaces with the plaster grinding machine. This is because of the device’s small weight, dimensions, and soft grinding disc suspension.

The SO-86 plastering and grinding machine has evolved into the standard tool for employing a single aluminum disc design. Polymer cement screeds and plastered surfaces are both smoothed and ground with it. Without raising the price of processing, this modernization of the working body has raised the caliber of surface finishing.

How to prepare the machine for work

Advice: After removing the grinding discs from the machine, install the left handle after buying it from the manufacturer.

• The completeness and reliability of fixing the parts is checked.
• External inspection determines the serviceability of:

1. electric cable insulation;
2. protective tube;
3. plug;
4. absence of defects in the housing and handles.

• Check the clarity of the switch.
• Control the operation of the machine when idling.
• Determine the direction of rotation of the disks.

Advice: If the direction of the arrow does not coincide with the rotation of the disks, you need to swap any two wires on the plug connection contacts.

• Check the smoothness of rotation of the disks for grouting by turning them by hand.

Once potential issues have been ruled out, you can start grouting the surface by hand.

How to grout the surface of walls

The guidelines for grouting the coating recommend:

• Connect the machine to the power grid.
• A rubber hose is attached for water supply.
• Bring the machine to the place of grouting on the wall of the plaster.

• Turn on the electric motor with your right hand.
• For some time it works idle so that the grinding discs gain the highest rotation speed.
• The machine moves smoothly over the surface being treated.
• The treatment area is moistened with water if necessary.
• The force applied to the handles of the device during work should not exceed 32 N or 3.2 kilograms.

Advice: When working, make sure that the trowel disks’ whole surface is in contact with the surface being treated. This will allow you to assess how worn they are.

• Worn disks should be replaced simultaneously. In this case, the ends of the screws that secure the inner trowel disk should protrude above the bosses of the disk made of aluminum by up to 0.5 millimeters.
• After replacing defective trowel disks, they must be trimmed in assembled form so that the surfaces of the two disks are in the same plane.
• Upon completion of work, the electric motor is turned off.
• The machine is disconnected from the network.
• The sleeve is disconnected from the water container.
• The machine is cleaned of dirt and plaster mortar.
• The power supply cable is wiped with a rag, carefully wound up.
• All components are placed in a case.
• Before storage, all faults detected during operation should be identified.

What safety measures must be observed during operation

In order to maintain safety when using a trowel, it is not permitted to:

• Operate the device in explosive areas where there is a chemically active environment that destroys metals and insulation.
• Work with a machine that has at least one fault and without periodic inspection.
• Ground the machine.
• Connect the unit without a frequency converter to the lighting network.
• Leave the machine unattended when connecting it to the power supply.
• Twist or pull the power supply cable, cause mechanical damage to it.
• Lay the electric cable near hot and oily objects.

A switch must be used to turn off the machine when:

• Contact of the half couplings of the connection with a plug.
• Connecting the unit to the power source.
• Unforeseen stoppage of the unit.

In the following scenarios, the device is plugged in and disconnected from the network:

• Replacing the grinding discs.
• Elimination of any malfunctions.
• Breaks during work.
• Moving the machine to another location.
• Completion of work.

If even a single one of the following issues arises, using the machine is forbidden:

• Damage to the plug connection.
• Defects in the cable insulation or protective tube for it.
• Unclear operation of the switch.
• Lubricant leaking from the gearbox or ventilation ducts.
• Appearance of smoke or odor, which is typical of burning insulation.
• Appearance of increased noise, unusual knocking, vibration.
• Appearance of cracks or even breakages in body parts, handles and discs.
• Loosening or damage to the grinding discs.
• Periodically, the machine must be serviced and checked by specialists.

Plaster grinding machines are an indispensable tool for professionals and do-it-yourselfers alike, as they streamline and expedite the process of smoothing surfaces. Compared to manual methods, it requires less effort to achieve a high-quality finish because of its efficiency and ease of use.

Selecting the ideal machine for your project can be facilitated by being aware of its features and principles of operation. Using a grinding machine correctly guarantees a smooth, even finish whether you’re working on walls, ceilings, or other surfaces.

You can save time and achieve professional-quality results on your plastering projects by purchasing the appropriate equipment and learning how to use it. It’s a useful tool that produces dependable and consistent results, which not only makes your work easier but also more fulfilling.

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