How Does Dynamic Milling Work?

There are a lot of machining terms that get thrown around, and chances are you’ve heard of dynamic milling. So, what is dynamic milling, and what do you need to use it?

What is a Dynamic Milling Strategy?

Faster CNC milling machines and advancements in their control software have led to a newer machining strategy: dynamic milling. It’s a strategy that takes smaller, deeper cuts. It offers a more efficient way to make parts (in most cases) and improves material removal rates. This approach relies on radial chip thinning.

What’s radial chip thinning? This method creates a smaller chip by using less than half of the cutting tool’s diameter. When less than 50% is used, the average chip thickness is less than the advance per tool flute. It’s important to remember your chip thickness still needs to meet the recommended chip load since you should always leverage the cutting tool’s capabilities.

With a smaller chip, its size may not be enough to hold the heat produced during milling, which could lead to your workpiece and tool absorbing the heat. To avoid this, you use faster feed rates. That way, there’s not much time for the heat to transfer before your coolant system blasts away the chips. Faster feed rates speed up the operations, so your run times are reduced.

DATRON AG discusses dynamic vs conventional pocketing strategies in their Tech Talk series

What Are the Benefits of Dynamic Milling?

• Removes more material with faster feed rates
• Constant chip load reduces tool wear and extends tool life
• Less stress on the machine, spindle, and workholding
• Get quicker cycle times with faster feed rates

The decreased stepovers and deeper stepdowns of dynamic milling benefit your CNC machine, workholding, and tools. Radial chip thinning keeps the chip load constant on your tool, so you never overload it. Maintaining a constant load puts less stress on the machine, spindle, and workholding. Also, this milling strategy uses more than just the tip of your cutter than traditional strategies like conventional pocket milling. Distributing the cutting force more evenly amongst the CNC tool will prolong its life.

What Do I Need for Dynamic Milling?

• Capable CAM software
• Carbide CNC cutting tools
• Milling machine capable of high acceleration and deceleration
• Machine control with high processing capacity

This strategy does have some requirements, which is why it’s not always an option for machinists. The milling machine needs to be rigid with repeatable feeds and speeds, but it doesn’t necessarily have to be a high-speed CNC machine. However, the machine does need to be capable of high acceleration and deceleration. Dynamic milling programs have lots and lots of code, so the machine control needs the processing capability to read lines quickly and keep up with the commands. The DATRON machine lineup is a good example of machines capable of dynamic milling. In fact, the next© control even has a mode for it.

Your CAM software calculates how to create tool paths to make the desired part, so it needs to be capable of writing a dynamic milling code. The tooling matters, too. The tool’s design, like geometry and coating, should be optimized for material removal.  We suggest using solid carbide tools, like DATRON’s line of carbide CNC cutters. Using higher quality tools means more durability and a longer tool life. So, you aren’t buying and replacing the tools as much.

So, should you always use dynamic milling? Ultimately, it depends on the operation and your machine capabilities. Certain shapes will not be milled faster using this method. If you’re not sure which milling strategy to use on your DATRON machine, our application engineer team is ready to answer questions just like that. For more general machining tips, you can explore our blog.