Long time CAD/CAM insiders have lived through many changes and tremendous progress. However, many consider the rate of improvement to have leveled off over the last few years, with most of the dramatic improvements already made. In this article, however, we will review one dramatic improvement that may catch you by surprise, Mastercam’s Dynamic Motion technology.
Though Dynamic Motion was first introduced in Mastercam X4, it is being integrated at different levels and into more product features of Mastercam.
What is Dynamic Motion?
The processes of conventional machining, found in most popular CAM products, are generally based on the geometric boundaries of the area to be machined. The toolpath is generated by following a simple principle: the tool has to cut material by changing its direction as it follows the shape of the part, finding its way to walls, islands, etc. But the cutting tool movement may not be optimal. In fact, sometimes it is just cutting air.
Mastercam’s Dynamic Motion generates tool movements not exclusively by the shape of the part. It also takes into account the amount of material being removed — which can change in the different phases of machining.
Efficiency of Dynamic Motion
The simulation of the paths created with the Dynamic Motion toolpath showed no abrupt changes of direction and resulted in a much smoother toolpath.
That, added to the total control of the lateral forces applied by the tool to prevent overheating, should result in less wear on the CNC machines, as well as a reduced chance of premature breakage and tool wear, and obviously a drastic reduction of cycle time.
Extending Tool Life
A key advantage of Dynamic Motion, and one of critical importance on the shop floor, is how it can extend the life of tools and machines. With conventionally generated toolpaths, only the tip of the tool flute is used. This causes uneven wear and requires multiple cuts and varying depths for removing all of the necessary material. Dynamic Motion technology solves these problems by using the entire length of the flute, and also achieves the following additional benefits, including:
• Heat distribution to the chip
• Less tool changes
• Less need for regrinds
• Decrease of vibrations
• Production of a consistent chip load
Figure 3: Dynamic Mill options dialog
Dynamic Motion toolpaths have expanded to include both milling and turning. In turning, Dynamic Motion is used to speed up roughing with a button insert by cutting in both directions.
Cutting Hard Materials Not So Hard with Dynamic Motion
Hard materials such as titanium and heat-resistant alloys are often complicated to machine due to a high risk of tool breakage, forcing the programmer to change speeds and cutting depths, and, in some instances, even the tool path. Dynamic Motion toolpaths claims to makes this task easier as its advanced rules include parameters that govern constant distribution of load and temperature of the tool.
Dynamic Motion for Old and New CNC Machines
At first glance, one might think that Dynamic Motion is exclusively dedicated to high-speed CNC machines, but smooth motion, less side load, and better use of tools produce more effective and faster roughing and should benefit any CNC machine, even older ones.
Know When to Use Dynamic Motion
While Mastercam’s Dynamic Motion technology is applicable to the majority of CAM processes, it does depend on certain combinations of geometry and cutting conditions/material consequently, and there could be situations where these “smart” toolpaths create more (but faster) motion than “conventional” toolpaths. This is why traditional CAM functions continue to coexist with Dynamic Motion toolpaths. Specific conditions may require a combination of both in one NC process.
Therefore, it is highly recommended that NC programmers go through the experience of simulation or testing with both (conventional and Dynamic) processes in the same types of parts prior to implementing this new technology in production.
Figure 6: Conventional area mill toolpath
Figure 7: Application of Dynamic Motion toolpath on the previous example
Conclusion
I can say without any doubt that Dynamic Motion technology optimized the process and significantly increased the efficiency in the toolpaths of the parts I applied it to. Others are reporting reductions in cycle times of more than 25 percent. However, the NC programmer is cautioned that there may be cases in which conventional toolpaths are more efficient than the Dynamic Motion toolpaths.
Dynamic Motion also acts to greatly extend the service life of the tool.
In short, Mastercam continues in the direction of the simple and perfect machining. Its Dynamic Motion is a breakthrough in the way that toolpaths are generated. Mastercam has succeeded in creating some excitement on the shop floor.
Mastercam sponsored this article but in no way influenced the content. The views and opinions expressed herein are those of the author.