How Does A Planer Work?

June 27, 2022

Thickness planer and hand planer.

You may be familiar with the word plane, yet you may end up a bit scratching your head when you hear the word “planer”. Of course, if you are a certified woodworker, you will exactly know what the word planer connotes. But if you are a newbie in carpentry, you might wonder about its functions. 

How to Use a Planer?

A planer is a tool designed to remove the thin, rough wood layer off the top sheet, plank, or board. You can use it to smoothen the surface of wood, including hardwood, plywood, and MDF. Some types of planers can also work well on composite and laminate boards. 

If you are fond of working with wood, you will come across a woodworking project that requires you to smoothen and shape the wood components you will use. You may also end up rounding rough corners or even flattening warped wood.

How Does a Surface Planer Work?

If you are new in woodworking and you want to find the best planer to use in your project, you may end up more confused, given the wide variety of forms and designs of planers at hand. You may opt for a manually operated planer, for example, that requires no electricity or settle for the more expensive bench planer or table model. Later, you will learn more about how the expensive bench or table models works. 

If it is your first time using the bench or table model of planers, you first need to set the table to the desired height. Do not forget to switch on the machine. Once you’ve turned on the electric planer, you can then feed the board into the machine until the in-feed roller comes in contact with the board. 

The in-feed roller then would grip the board and pull it past the rotating sharp cutter head. As the board makes contact with the sharp cutter head, the blades shave the rough material off the wood’s top sheet. On the other hand, the out-feed roller pulls through the board, eventually ejecting it from the equipment.

To create a uniform and flat thickness throughout its length, you must have a board with one perfectly flat surface that you can use as the reference face. You can then lay the board flat on the table with the reference face facing the table. It would then be best if you run the board through the planer again to flatten the rough opposite side. 

Now, you may be asking how to make a reference face when both sides are rough and not flat. The answer is simple. It will be best if you run the board first over a jointer. A jointer may be a separate machine or part of the planer as a jointer/planer combo. In this way, you will have a reference face on one side of the wood. 

How Do Thickness Planers Work?

A planer is a machine you can use to provide wood with uniform thickness. You will find the planer more complicated in design than a jointer. Nevertheless, it has a more straightforward functionality. To use the planer, you only need to set the flattened board on the planer table and push the board onto it. The feed roller of the planer grabs the board and pulls it onto the cutter head of the planer. 

You will see the cutter head above the bed, and it reduces the size of the wood into a uniform thickness. You can set the distance of the bed to the cutter head. This distance becomes the resulting thickness of the wood. 

The planer, of course, can only remove a certain amount of wood in one pass. Thus, to get the desired uniform thickness of the wood, you need to make multiple passes.

If you inspect the different components of a thickness planer, you will find three essential elements: the cutter head, the roller set, and the table. The cutter head features cutting knives that remove wood. It is a cylinder that spins at tremendous RPM and cuts the wood as it gets fed through the planer. 

The roller set draws the board toward the cutting head and out on the other side. This roller set consists of two rollers that apply downward pressure onto the wood to keep the wood flat at the bottom. The table is adjustable relative to the position of the cutter head. However, some thickness planers have fixed tables with adjustable cutter heads. 

You will find some industrial thickness planers as you shop around for thickness planers. These thickness planers can accept wide and thick wood. Moreover, you can remove a large wood amount using these thickness planers in a single pass. 

Besides, these industrial thickness planers come with powerful motors. They are also heavily set and designed for heavy-duty tasks. 

If you’re a DIYer, you can go for portable thickness planers, which have become widely available recently. These portable thickness planers are less expensive. Nevertheless, they operate noisily and come with universal motors instead of injunction motors. 

You will also find planers with jointer and thickness planer functionalities. So, instead of buying two separate machines, you will have both functionalities in a single device. You will often find this type of machine in Europe.

Planer Vs Jointer: How Do They Differ?

The planer and jointer might look the same to a beginner in woodworking. But they are entirely different from each other. The jointer, for example, flattens the surface of the board while straightening and squaring an edge. It provides the wood with a flat surface on the bottom of the board, but it doesn’t provide a uniform thickness. 

The thickness planer, however, provides the board with uniform thickness, but not necessarily flat and square surfaces. For this reason, you will need a jointer and a thickness planer to produce a board with a uniform thickness and flat surfaces. 

The difference between the jointer and the thickness planer becomes apparent if you’re working on a bowed wood. The jointer, for example, provides the wood with a flat bottom surface that you can use as a reference when you pass the wood through a thickness planer to achieve a flat board with uniform thickness.

Types of Planers

The planer, as a tool, has evolved throughout the centuries. There are myriad types of planers; some are manually operated, while others are electric-powered. Manual planers include hand planers, two-handed planers, combination rasp planers, flat plane bottom-edged wood hand planers, and hand scrapers. On the other hand, electric planers include handheld electric planers, bench planers, molding planers, stationary planers, metal planers, etc. We will discuss in this article more on electric planers and how they function. 

Problems of Using an Electric Planer

There is an issue that you may run into if you are feeding a board which has a lower face that is not flat. When the feed roller presses, for example, on the board against the planer or table, you may end up deforming the board instead of flattening the upper surface. The board may also spring back while the machine ejects it. And this may result in an uneven upper surface.

Another problem when utilizing a thickness planer is that of snipe. A snipe is a deeper cut on any of the board’s short sections at each or either end. Misalignment or incorrect feeding on the in-feed or out-feed tables or inappropriate high rollers setting may cause the onset of snipes. Yet, you can correct the snipes by keeping the board for later trimming.

What Are The Differences Between Surface Planer and Thickness Planer?

When buying a planer, you will undoubtedly encounter along the way electric-powered planers that are marketed as thickness planer or surface planers. These two may look the same, and many manufacturers may interchangeably use these two phrases for marketing their planers. Yet, there are remarkable differences between these two models of planers that would be good to note:

The Surface Planer

You may get intimidated by the surface planer’s imposing design if you are a beginner in woodworking. Yet, the surface planer is a machine that focuses more on working on all surfaces. It has the cutter head on the table’s bed surface to create an even surface out of rough lumber. It is good to note that the surface planer is a bit better when it comes to producing the reference face compared to the thickness surface. 

The wood’s reference face is the side of the wood that is already flat and is used as a reference when flattening the other side of the lumber. You will need the reference face when smoothening all sides of the lumber. The good thing about the surface planer is that it can create a reference face in a single pass. 

The surface planer model also has a more specific target. It only targets a small area of the wood surface at a time. This type of planer may be manual or electric. 

The manual model requires you to use pressure to smoothen and cut across the wood surface. On the other hand, the electric model features a motor that produces the needed pressure to work on a specific surface. Moreover, the surface planer’s cutter head may not go deeper compared with the thickness models.

Thickness Planer

The thickness planer, on the other hand, may look like the surface planer. This type of planer is designed to trim lumbers and boards to produce consistent thickness along the board’s length, resulting in a flat surface on both sides.

The thickness planer also has some remarkable advantages over the surface planer. First, it can create a board that features a consistent thickness. Second, it can also avoid producing tapered boards. Moreover, you can use it for initially preparing an un-planed board. Strictly speaking, the thickness planer only focuses on thickness.

The thickness planer may not be as good in creating a reference face as compared to the surface planer. Yet, it also has some remarkable advantages over the surface planer. First, it can create a board that features a consistent thickness. Second, it can also avoid producing tapered boards. Moreover, you can use it for initially preparing an un-planed board.  

One distinct characteristic of a thickness planer is that it has a cutter head with several knives that vary in number depending on the manufacturers. It also comes with rollers that let the wood travel smoothly through the cutter head once the board is pushed. Other models come with an automatic feeder that, instead of pushing the board, pulls it in and pushes it out on the other end.

Another distinct feature of the thickness planer is its tray or base. The table model comes with a table tray or base wherein you can lay the wood. Other models have metal trays on which you can sit the wood. These metal trays extend out to allow you more elbowroom to work on the wood in some instances.


Whether a thickness or surface model, planers will definitely make your woodworking tasks easy and manageable. Planers can help prepare the boards for your projects. With their use, you can remove any amount of rough surface as needed. You can also assure yourself that you can remove splinters before using the boards as your project’s components. By learning how to use planers, whether it is electric or manual, you are in a better position to start your woodworking projects and avoid the usual pitfalls that come with the use of different types of planers. 

As you learn to distinguish between the jointer and the planer, you will discover that both machines are essential to achieving quality wood projects. The jointer, as mentioned above, provides your wood with a flat face and squared edges, while the planer provides your wood with a uniform thickness. Their operations and functionalities, of course, are not interchangeable. 

These two machines are expensive, and if you’re a DIYer, you might not yet have owned any of these two machines. The good thing is that you can now find portable thickness planers that combines the functionalities of both the thickness planer and the jointer.

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