Routing Methods in Woodworking

Where there's planing, there are shavings – and that also goes for the 'successor' of the classic plane, which is often a computer-controlled milling machine today. With modern milling tools, you can carry out a variety of machining operations, allowing you flexible and precise high-level production in woodworking.

What are milling processes and which method is best suited for your purpose? In this article, we'll explain which milling processes help you achieve quality results and give you an overview of milling techniques in woodworking. You'll also learn the advantages and disadvantages of each milling process and what you should consider before choosing one.

Table of Contents

• Definition
• Overview of Milling Processes
• Classification
• Routing Methods in Woodworking
• Milling Processes by Direction of Cut
• How do Milling Processes Differ?
• Milling Processes – Pros and Cons
• FAQ

Definition: What are Milling Processes?

'Milling process' refers to a machining technology where material is removed from the workpiece by the circular motion of a milling cutter. You can use it to process wood, metal, and plastic. In woodworking, milling tools are used in furniture and interior construction or window manufacturing to achieve functional and decorative effects with special milling inserts. Only a targeted selection of milling processes and milling inserts will ensure you get a high-quality result.

Overview: What Milling Processes Are There?

The milling process you choose depends on your project's requirements. You can machine workpieces on milling machines using these methods:

• CNC Routing
• Profile Milling
• Face Milling
• Form Milling
• Circular Milling
• 3D Milling
• Face Milling
• Thread Milling

Tip: The router table (a portable table-top router) offers you a semi-stationary system that combines precise routing with a stable worktable and great flexibility.

Precise Milling onrouter table

How are milling processes categorized?

Material, intended use, and shape all play a role when machining a workpiece. These parameters help you find the right milling process.

Simple, cylindrical, and flat surfaces:

• Face milling for flat surfaces and steps, with a straight-line feed
• Cylindrical milling for cylindrical surfaces (e.g., round tenons, internal or external curves)

Milling profiles:

• Profile milling with a special profile milling tool that gives your workpiece a contour in a single pass

Curved surfaces, especially in mold making:

• Form milling using controlled feed movement for complex, spatial structures (e.g., NC form milling, copy milling)

Highly productive and efficient:

• CNC milling, 3D milling are fast, versatile, and precise, especially for complex shapes or series production parts

Overview: Milling Processes in Woodworking

When you're using milling machines in wood processing, you expect efficient and precise results. Each milling process is designed for specific machining operations to produce workpieces cost-effectively.

CNC Routing

These are computer-controlled milling machines with high-speed spindles and plenty of tool stations. They're great for furniture making or other woodworking shops that benefit from their versatility and speed.

Circular Milling

With special cutter heads, you can create round tenons or cylindrical shapes. You can also use them to clean up round saw cutouts.

Form Milling

Form milling is suitable for complex, three-dimensional designs or profiling. It's usually done on CNC machines to achieve high precision.

Thread Milling

Milling in screws, threads, or spindles using suitable thread mills (e.g., multi-range or drill-thread mills). In woodworking, dovetail cutters are often used to create strong dovetail joints.

Face Milling

Face milling is the most important milling process across industries for producing smooth, flat surfaces. Users most commonly use milling heads with a 45° lead angle, which allows for low vibrations with good productivity.

Face Milling

This is for large-area material removal. You can achieve smooth surfaces with consistent quality. There's a wide range of tools available with different rake angles.

Profile Milling

Many decorative milling operations in the furniture industry are performed using profile cutters. Curves, slots other decorative elements on moldings and cabinet fronts are typical applications. Typical radii range from 4 to 18 mm.

3D Milling

Nowadays, 3D milling is affordable even for small businesses. It allows for an extensive variety of shapes and automated processes, especially with form milling. You can use it to realize even unusual customer requests.

Milling Processes by Direction of Cut

The milling direction is defined by the feed direction and the tool's rotation direction. This is important in woodworking because you should ideally mill in the direction of the wood grain. We distinguish between:

Climb Milling

The feed runs opposite to the cutter's rotation direction. The chip thickness increases, which can raise heat and friction and lead to vibrations – especially with thin workpieces. So, make sure you precisely adjust the feed rate and RPM.

Conventional Milling

The cutter's rotation direction and feed direction are the same. This means the cutter 'pulls' itself through the material, creating a polishing effect, but it can be harder to control. There's a higher risk of accidents, and in some environments, climb milling isn't even allowed.

Milling operation onrouter table

How do Milling Processes Differ?

Each milling process is designed for a specific application: whether you want to create profiles, steps, surfaces, or threads, each process uses different cutter heads and settings. Key factors are the cutter position, arc of engagement, angle of engagement, and choosing between climb or conventional milling. When combined with CNC systems, you can achieve very precise and diverse machining operations.

Milling Processes – Pros and Cons

When selecting a milling process, you're looking for the optimal balance between cost-effectiveness and machining quality. Unlike metalworking, wood milling doesn't use liquid cooling. This is crucial for hardwoods to prevent the tool or workpiece from overheating and getting damaged. So, make sure you have a coordinated combination of feed rate, spindle speed, and cutter diameter.

Whether you choose climb or conventional milling depends on your experience. Conventional milling is safer, but it puts more stress on the cutter and workpiece. Climb milling is gentler on the material, but it requires more routine and a precisely adjusted machine setup.

FAQ

How are milling processes classified?

Classification is typically based on:

1. Type of material processing (e.g., face milling, peripheral milling)
2. Feed rate and direction (conventional milling, climb milling)

Milling processes are also often classified by milling machines, milling tools, and materials.

What milling processes are there?

The most common processes include: CNC milling, profile milling, end milling, form milling, circular milling, 3D milling, face milling, and thread milling.