Dynamic milling
What is Dynamic Milling?
Dynamic milling is a modern machining method developed in collaboration with tool manufacturers and CAM software developers. This method is specifically designed for the efficient roughing of difficult-to-machine materials such as hard steels and heat-resistant superalloys. However, dynamic milling is also excellently suited for milling other workable materials. The core of the method is utilizing the full cutting depth of the tool, which allows for even tool wear and extends tool life.
Technical Features of Dynamic Milling
The basic principle of dynamic milling is a large axial (ap) and small radial (ae) cutting depth compared to traditional machining methods. This means the tool is not used at its full width, and material removal happens in smooth, flowing toolpaths. In dynamic milling, straight-line motions are avoided, and machining is mostly done via climb milling. After each pass, the tool returns at high feed to the start of the new cut, using a curved entry and exit motion onto the toolpath.
Practical Applications of Dynamic Milling
Dynamic milling is widely used in machine shops and manufacturing plants. The tool diameter (Dc) should not exceed 70% of the width of the area being machined. The lateral step-over for dynamic high-speed milling (ae) is usually about 5-20% of Dc, depending on the tool and the material. For example, when milling closed pocket shapes, it is recommended to use air cooling rather than a coolant emulsion to prevent chips from interfering with the machining process.
Compatibility and Optimal Use of Dynamic Milling
Dynamic milling often requires advanced CAM software, such as Mastercam, which can generate the necessary NC code. This NC code is often long and more difficult to read without CAM software, making manual editing virtually impossible. In addition, older machines may struggle to read and process lengthy NC codes.
Advantages and Disadvantages of Dynamic Milling
Advantages:
- Higher cutting speed: Allows for larger machining parameters.
- Greater feed per tooth: More efficient material removal.
- Increased chip flow: Continuous material removal.
- Shorter machining time: Improves process efficiency.
- Better chip control: Reduces tool wear.
- Lower heat generation: Extends the life of tools and workpieces.
- Lower tooling costs: Tools last longer.
- More reliable machining process: Less vibration and higher precision.
- Lower power requirements: Reduces energy consumption.
Disadvantages:
- Lengthy NC code: Requires significant memory and processing capacity.
- Complex machining programs: Requires CAM software.
- Manual editing of NC code impossible: Relies on the output from software.
- High memory demands for machine controllers: Increases the memory requirements of machines.
- Compatibility with older machines: Older machines may struggle with lengthy and complex codes.
Summary
Dynamic milling is an advanced and efficient machining method that maximizes the cutting depth of the tool and offers significant improvements over traditional machining processes. The advantages of the method—such as higher cutting speeds, better chip control, and lower heat generation—make it a popular choice in machine shops and manufacturing plants. However, effective use of dynamic milling requires advanced CAM software and modern CNC machines capable of processing complex and long NC codes.
