Milling in woodworking
Definition and explanation of manufacturing technology
Milling is the removal of any desired contours from a standing workpiece. It is one of the machining processes. Milling is a broaching process used to shape workpieces.
Milling is a machining process with many possibilities. In this article you can read how milling works and what you need for it. You will also learn from us the technical basics and methods that are used when milling wood.
Table of Contents
Meaning: Milling simply explained
Milling is a machining and shaping process. It can be used for all solid materials. The milling of wood is characterized by particularly simple and easy-to-use devices. This differs significantly from metal milling. Any contours are removed from a workpiece during milling. This can be the surrounding contours. Milling is also used to designate grooves, steps, pockets or hole patterns. In addition, milling machines are also suitable for leveling wavy or cracked surfaces. This makes this processing method particularly versatile.
What types of milling are there in woodworking?
There are numerous types of milling. A distinction is made according to the running direction, the type of material or the shape that you want to discharge. A major dispute is always the question of the running direction. Here you can choose between climb and up-cut milling.
Milling process overview
Milling is divided into manual and CNC processes for both metal and wood. Manual milling is guiding the workpiece or the milling cutter by hand. With CNC milling, the workpiece is clamped and processed using an automatic guidance system. For do-it-yourselfers, manual milling is usually the only option.
The manual milling process can be further divided into freehand milling and jig milling. With freehand milling, the cutter or workpiece is guided through the material freehand. Milling machines or routers are available for this purpose. For jig milling you need the eponymous milling jig. This gives the user a whole range of additional editing options. With the milling device you can carry out the following milling processes safely and with good results:
Milling process according to running direction
When dividing the milling processes according to the running direction, one looks at the feed in comparison to the direction of rotation of the milling cutter. If the milling cutter rotates in the same direction as the feed at the machining point, this is called climb milling. If the feed moves in the opposite direction to the direction of rotation, this is referred to as up-cut milling. We would like to advise you against climb milling right at the beginning. It can quickly become dangerous, especially for inexperienced do-it-yourselfers.
Up-cut milling is the processing of a wooden edge against the direction of rotation of the milling head. The feed can easily be controlled by hand. The removal is quick and large. There is one disadvantage: the edge can easily splinter when milling in the opposite direction.
The advantage of climb milling is the smoother edge. On the other hand, manual guidance is much more difficult with this milling process. The milling cutter constantly wants to throw the workpiece away. The operator runs the risk of reaching into the rotating milling head. We can therefore not recommend this milling process. It is better to mill the contour counter-current and then grind it smooth.
Technical basics of milling
A milling machine is required for milling. The simplest form of wood milling machine is the router. It consists of a powerful motor that achieves both high torque and high speed. The router is equipped with a chuck. This can be equipped with different milling cutter types. Routers are also good basic machines for table routers or routers.
The cutting width indicates how wide a groove will be that is to lead through the middle of the material. The cutting width is slightly larger than the diameter of the milling head.
The feed is the speed at which the cutter is plunged into the material. The harder the material, the wider the milling head and the more complex the contour, the slower the feed should be.
The cutting speed is the speed at which the cutter is fed through the material. It depends on the following factors:
- hardness of the base material
- width of the milling head
- Rotational speed of the milling cutter
- torque applied to milling cutter
- feed rate.
It is very important to know beforehand exactly how to set up and operate a machine. To be on the safe side, you should proceed a little more slowly. Too much feed or too high rotation speed of the milling cutter can cause damage to the machine and the product.
Milling tools for milling wood
The most important tool when milling wood is the milling head. This is interchangeable. There are hundreds of different designs and types of milling heads to choose from. Here are some examples:
- roughing cutter
- Disc grooving cutter
- rebate cutter
- end mill
- drill milling cutter
- Milling cutters with interchangeable inserts
- Milling cutters with interchangeable cutting edges
Choosing the right router bit for every job is also part of safe and professional handling of the wood router. This leads to the best results and puts the operator, product and tools at the least risk.
Milling materials used
Woodworking machines can only reliably process comparatively soft materials. Separate machines are available for metal products or minerals. Although these are technically similar, they are geared towards different materials. Milling with a wood milling machine, especially when working manually, is therefore limited to wood and homogeneous plastics. In addition to solid wood, chipboard, plywood panels or laminated beams can also be processed well with wood milling machines.
Overview of materials:
- cast aluminum
- wood materials
Milling in woodworking professions
In addition to turning or turning, milling is the most important processing method in wood processing after sawing. It gives a product its form or prepares it for further processing. Accordingly, milling machines are used in practically all woodworking professions. This includes the following trades:
- Carpenter / cabinet maker
- boat builder
- instrument maker
- stair builder
- interior decorator
and many more. Milling machines are becoming increasingly important in carpentry. They make it possible to make precise tenons and holes in beams. This brings the traditional art of half-timbered construction back to life without angles and nails. Regardless of whether a fine inlay is to be placed in a cupboard door or a tree grate is to be leveled – the router with its variations is always the best choice for complex tasks in wood processing.
Practical application: What can you mill?
Milling, especially working with a milling device, is a versatile field of activity. With the help of these simple but powerful tools, even a layman can quickly achieve good results. Typical milling applications are as follows:
- face milling
- format milling
- Profiling / profiling
- structural milling
- Grooving – Milling a groove in wood
Face milling is the leveling of a surface. With the help of the milling device, even a beginner can get a rough piece of wood nice and smooth. It is particularly advantageous that tree discs can also be smoothed with the milling device. This is not possible with a planer without damaging it.
With format milling , a workpiece is brought into the desired angularity. Milling out right angles is particularly easy. But with a little skill, you can also learn to bring in any angle you like.
Structural milling is the processing of the workpiece on the surface. This includes the introduction of hole patterns, pockets or recesses. Contour milling is particularly easy and precise on a milling device.
Historical background of milling
Milling has a long tradition in woodworking. Even Stone Age people made drills out of bone, with which they could drill holes in wood. Together with some sand and a bow, our ancestors were able to create amazing works of art with these simple means. The simple processing of wood has allowed the art of milling to continue to develop over the generations. When the first ships and wooden furniture were built, tool development also experienced further impetus. China, India and Japan emerged early on with exquisite craftsmanship. The main tools used there were knives, chisels, chisels and saws. But the art of milling was also used in medieval Asia. At the latest with the industrial revolution, the processes that we know today were developed. These were then adapted to metal processing. This is how milling became one of the driving forces behind today’s precision manufacturing.