The random orbital sander is a tool that is absolutely necessary sooner or later during the renovation of various premises. It is considered an effective and versatile tool for polishing and sanding surfaces. When the focus while working is on the quality of sanding, the eccentric sanding is incomparable. This is its main difference from all other types of sanders. It is able to guide the surface to perfect smoothness without sawing and visible scratches.
With our big random orbital sander test 2021 we want to help you choose the right random orbital sander for you. We have compared a classic, a cordless and a compressed air random orbital sander with each other and listed the respective advantages and disadvantages to make your purchase decision easier.
- 1 Weekly newsletter with the best personal finance tips
- 2 Summary
- 3 The Best Random Orbital Sander: Our Choices
- 4 Buying and evaluation criteria for random orbital sanders
- 5 Decision: What types of random orbital sanders are there and which one is right for you?
- 6 Guide: Frequently asked questions about random orbital sanders answered in detail
- 6.1 What is a random orbital sander suitable for?
- 6.2 What should a good random orbital sander cost?
- 6.3 How does a random orbital sander work?
- 6.4 What does eccentricity mean on an eccentric sander?
- 6.5 What should the power of an eccentric sander be?
- 6.6 Random orbital sander or orbital sander: What are the differences?
- 6.7 The sanding discs: What should I look out for?
- Eccentric machines are universally applicable. They are not only suitable for sanding wood and metal, but also for painted surfaces. They are often used for polishing finished surfaces.
- Eccentric sanders are only suitable for dealing with flat surfaces. It cannot be used in corners, which means it is not suitable for sanding muntins and shelves.
- With a total power of 280 watts + an oscillating circuit of 3 mm + 125 mm sanding disc, the random orbital sander is perfectly adequate for a high-quality result and productive work.
The Best Random Orbital Sander: Our Choices
Buying and evaluation criteria for random orbital sanders
In order to make the right decision when choosing an orbital sander, you should first look at the important evaluation criteria.
The criteria you should look for when buying a random orbital sander include:
To avoid spending money on unnecessary features, it is worth taking a closer look at these characteristics.
Oscillating circuit & idle speed
Oscillating circuit is also called eccentricity. Another explanation is the imbalance of the sanding disc. The value varies from 2 to 8 mm. The greater the value of eccentricity, the more productive the sander.
Productivity as well as the level of finish are directly dependent on this amplitude. A tool with high amplitude and corresponding productivity is required for grinding in materials with high hardness.
When choosing a random orbital sander, you should always pay attention to the idle speed. This is the rotation frequency. This is the number of revolutions of the eccentricity per minute.
- For machines with a "regulation" option - between 4,000 and 14,000 Rpm
- For unregulated machines - about 12,000 rpm
Many units have electronic stabilisation that reliably controls the number of revolutions.
For random orbital sanders, this parameter offers from 130 to 900 watts.
But usually the power of several machines varies between 220 and 450 wat ts. The "strength" of the tool has a direct effect on its power. So it is not surprising that 400-watt machines have a sanding disc with a diameter of 150 mm.
The 3 main diameters of sanding discs are - 115, 125 and 150 mm. A small disc is usually for amateurs, the medium are semi-professional tools, and large - professional sanders that can easily handle large surfaces.
- "125 mm" - most commonly used size. There are enough compact, lightweight, relatively inexpensive machines. Many models of this size have a handle. The smaller size makes it easier to work in places with limited access.
- "150 mm" - these machines are relatively large, are made on a two-handed circuit (with the front and rear handle). However, larger diameters increase the efficiency of grinding as they are equipped with a 300-500 watt motor.
The size of the sole should always match the power capacity.
The weight of a random orbital sander can vary between 1.2 - 3 kg.
Sometimes it is necessary to polish the ceiling or elements at height. That's when you need a simple tool to do difficult tasks.
Small machines are better suited for everyday tasks, do not overload the hand and lead to productive work. After all, it is uncomfortable to work with a heavy tool suspended in the air.
Volume & vibration
Many users complain that their hands get tired quickly during work and that they suffer pain from excessive vibrations. To solve this problem, manufacturers equip tools with an anti-vibration system that works on the principle of dynamic counterbalance.
Before buying, it is also helpful to read the reviews of a particular model to consider the vibrations during operation.
Working with a machine that vibrates strongly in the hand is not only uncomfortable, but also not good for your health in the long run. Switch on the machine when you buy it and hold it in your hand - vibrations should be completely absent.
The optimal volume of the machine varies between 60-80 decibels. We would still advise you to use headphones.
Working with a sander is not possible without creating large amounts of dust and waste. Equipping the tool with an adapter through which the hoover can be connected makes the process of dust removal much easier. Working with the tool becomes much more comfortable.
The high efficiency of dust removal is ensured by holes in the working disc.
The holes in the sandpaper must exactly match the holes in the sanding disc, both in diameter and position. This should be taken into account when buying replaceable sandpaper.
Decision: What types of random orbital sanders are there and which one is right for you?
Let's analyse the 3 different types of random orbital sanders with their advantages and disadvantages:
|The classic random orbital sander||Universal:can sand as well as polish||Depends on cable length|
|The compressed air random orbital sander||Compact + Lighter weight||Depends on compressor power|
|The cordless random orbital sander||Mobility:does not need a cable + Does not depend on a power outlet||Battery lasts only a limited period of time (about 1 hour)|
The following information will give you the knowledge you need to decide which of these machines is right for you. You will learn what the main differences are, as well as their strengths and weaknesses.
Guide: Frequently asked questions about random orbital sanders answered in detail
What is a random orbital sander suitable for?
The Universal Power Tool handles a wide range of tasks. Typical jobs for which a random orbital sander can be useful:
- Careful sanding and polishing of metal, wood, plastic, etc.;
- Cleaning the surface of paint and varnish;
- Finishing walls and ceilings;
- Refinishing of plastic and plexiglass.
At the same time, this type of sander is only suitable for dealing with flat surfaces. It cannot be used in corners, small grooves and recesses, which means it is not suitable for sanding glazing bars and shelves.
What should a good random orbital sander cost?
The prices for a random orbital sander start at 40 €. The appropriate price for a random orbital sander can best be determined according to the following 3 consumer types:
|Craftsman type||price range|
|The occasional user||€40-100|
How does a random orbital sander work?
The special structure of the movement path prevents small particles from damaging the surface.
In oscillating movements, the vertical axis, which passes through the centre of the sole, shifts relative to the other axis of the motor. The displacement is indicated by the amplitude of the eccentric oscillations. (Oscillating circuit)
What does eccentricity mean on an eccentric sander?
The greater the eccentricity value, the more productive the sander.
On the "slow speed", when the vibrations are concentrated on a smaller area, the sanding will be finer. However, this does not mean that machines with low eccentricity should not be considered when buying. They are quite suitable for small volumes of work where speed is not as important as the accuracy and quality of the grinding and polishing.
What should the power of an eccentric sander be?
For everyday use at home, 5,000 to 8,000 revolutions are sufficient.
To roughly finish metal surfaces or to sand seams after welding, you need about 12,000 revolutions. Soft wood or plywood needs a specific average speed.
Random orbital sander or orbital sander: What are the differences?
|Orbital sanders||Eccentric sanders|
|1. Has a square sanding plate||1. Has a round sanding plate|
|2. Has a circular oscillating motion||2. Has an eccentric oscillating motion + a circular motion|
|3. Has a lower stock removal rate||3. Has a higher stock removal rate|
|4. Are good for small work surfaces and narrow edges||4. Are good for finishing large flat work surfaces|
They differ both in shape and working principle.
The sanding discs: What should I look out for?
Typically, there's a plastic disc that fits tightly against the soleplate on top. This mechanism helps to make the rotation of the sole around its axis smoother, which in turn affects the quality of the sanding.
The advantage is that work breaks are reduced and the likelihood of spoiling the surface is reduced.
Image source: Kovtunenko/ 123rf.com