At first glance, the principle of operation of sanding machines is the same. They smoothen the surface of a material with an abrasive tool. However, you need to clearly understand the purpose of each type of these power tools if you want to make an informed choice.
In each specific task, one type of sander will show itself brilliantly, while the other will not give the expected result. For example, random orbits cannot handle internal corners while orbital sanders can do the job. On the other hand, random orbital sander are first choice if a surface needs to be super-smooth.
In this article, we will discuss the differences between the orbital sander and random orbital sander. These handheld tools differ in the type of abrasion movement, as a result in the sanding pattern, and in the possible applications. Let us examine the differences and similarities of both tools and determine the scope of application for each of them.
Check out our article Orbital Sander vs Palm Sander if you consider a palm sander as an alternative. *people photo created by freepik - www.freepik.com
Most modern sanders are equipped with a dust removal system. A construction vacuum cleaner is either connected through a special pipe, or a dust bag is included. This makes the work process cleaner, the tool itself is controlled better, and the consumption of abrasive tooling is reduced. It is also much healthier but wearing a mask is recommended anyway (read more about DIY safety in our dedicated article).
By the type of power supply, orbital and random-orbit sanders are divided into electric and battery tools. The advantages and disadvantages of the wireless versions are obvious: It has better mobility and retains independence from the power grid. However, the running time is limited by the battery charge.
What Is an Orbital Sander?
This machine has a mass from 1 to 3 kg, equipped with a rectangular sole with a clamping mechanism on the edges, which is able to fix most standard sanding paper. There are also models with the option to fix the snap to the sole with Velcro, which requires a Velcro-compatible sand paper though.
The Bosch GS20-40, one of the most popular orbital sanders on Amazon.
The sole makes reciprocating movements in a circular orbit and due to this, sanding or polishing is performed. The power of the electric motor of this tool usually ranges from 150 to 600 watts. The sole can be of two types: standard - 100 X 200 mm, and mini versions with a base of about 100 X 100 mm.
Here, the choice is simple: mini surface sanders are suitable for narrow spaces, they are lighter and more maneuverable than standard ones.
This standard sander is designed for the delicate processing of large flat surfaces, so it allows faster progress on larger chunks like floors or slats. With the help of a fine grit abrasive, they perform a final polishing of various surfaces: wood, plastic, and stone.
Advantages: the ability to sand and polish internal corners, the availability of consumables and attachments as well as the reasonable cost of the power tool itself.
Disadvantages: high noise relative to the random orbit.
What Is a Random Orbital Sander?
Random orbital sanders are considered the most effective and versatile tool for polishing and sanding surfaces. In professional and manufacturing environments as well as in private use, they show the best results in surface finish quality.
Polishing and sanding are possible thanks to a combination of rotational and eccentric movements of the rounded sole. The sole rotates in orbit and simultaneously scrolls around its axis. Such a complex movement of the abrasive allows you to sand effectively with a minimum of flaws.
The machine, weighing from 1 to 3 kg, is usually equipped with a round sole with Velcro, which is attached to the abrasive wheel on a felt basis. Soles come in two sizes - diameters: 125 and 150 mm. Machines with a sole of 125 mm are lighter, designed for smaller areas and for more delicate work than sanding machines with a sole of 150 mm. Electric motors consume from 200 to 900 W. A high-power machine provides greater performance. When installing the equipment, it is important that the holes on the sole of the tool coincide with the holes of the abrasive wheel, otherwise the process of dust removal will be difficult.
This sander is used for rough or delicate abrasion on large surfaces, for interlayer processing of materials and coatings, for polishing, processing large surfaces along and across fibers. Often machines of this type are used in carpentry and car painters.
The Advantages: Random orbits do a great job in all kind of projects between large and rough surfaces (where you might consider a belt sander) and small complex surfaces. This tool is the first choice when a particularly smooth result is important. The noise and vibration levels are less than other types of sanders.
The disadvantages are obvious: these sanders are not suitable for processing internal corners and grooves. Productivity is small in comparison with belt sanders (learn more about their “siblings” with a belt).
Sanding sheets are available in many different grits (check prices on Amazon).
Orbital Sanders vs. Random Orbital Sanders
Now, Let’s compare their features head-to-head so you practically understand why and how to use each of them.
1) Type of Abrasion Movement
The classic orbital sander usually has a square grinding plate. This sanding plate oscillates eccentrically. The sandpaper is usually clamped by clamps or fixed with Velcro. It has a square bottom and it stands by just moving back and forth in the same motion over and over again.
The orbital sander has less abrasion than the random orbital sander due to its oscillating motion. It has a tendency to leave marks that are obvious that it was just moving back and forth in the same motion Ideally, you will use the orbital sander if you want to work along edges.
In contrast, the random orbital sander has a rounded sanding pad. This sanding pad rotates eccentrically. The sandpaper is usually stretched with a climbing. Due to its rotating movements, the removal is significantly higher than with the orbital sander.
A random orbit sander tends to be far more aggressive in performing the sanding. Therefore, if you put the same grit sandpaper on a random orbit versus an orbital sander, the random orbit is going to take down the sandpaper grit much faster.
2) Sanding Results
When working with the orbital sander, it may happen that in some places the sanding pattern is not uniform.
Due to the reduced removal of the orbital sander, the surface must be processed more often than with the random orbital sander. With the random orbital sander, the sanding pattern becomes a lot finer than with the orbital sander and the surface (eg. tabletop) gets a nicer and finer sanding pattern.
3) Different Uses
We will divide the two sanders into different categories. Both types of equipment are best suited for surfaces of wood or plastic. However, more time is needed with the orbital sander because the removal rate is lower than with the random orbital sander.
For large surfaces such as table tops you should prefer the random orbit. If you want to work on workpieces with a complex surface or with many corners, you should use an orbital sander.
The orbital sander can also be used for other applications, such as polishing or sanding a drywall.
Orbital sanders are the cheaper options with prices ranging from as low as $25 up to a couple hundred dollars for top-notch tools. However, quality orbits for DIYer are available for $50 to $80 (check current offers on Amazon).
Random orbital sanders come with similar price tags but there are much more different models available on the market. Check prices on Amazon or read our expert reviews of the most popular random orbits to understand the differences.
In principle, the devices have very similar fields of application. The orbital sander is very well suited for corners, complex surfaces and smaller objects to be sanded. The random orbit, on the other hand, is the better choice for large surfaces and where a smoother outcome is a priority. The removal rate and the abrasion pattern are also a lot higher or better with the orbital sander. Therefore:
- If you need an universal tool for sanding a large number of different materials, you should choose an orbital sander (check latest deals on Amazon).
- If the tool should be universal, but used on rather large and even surfaces, and if there are high expectation on the quality of the sanding, you will want to make a choice in favor of a random orbit sander (check out available models on Amazon or read our expert reviews).
So, what types of sander do you mostly use in your garage or workshop? Let us know in the comment below!
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