Five Axis Made Easy
- February 8, 2012
By Jeff Fritsch, CAMplete Solutions
More than ever, it is crucial that North American part manufacturers constantly improve their technology and processes to compete globally.
As production runs shorten and part geometries get more complex, five axis machine tools are starting to go mainstream. The efficiency and ROI possible with what once were considered specialty machines, is now making an impact on many shop owners.
Even though the benefits of five axis are attractive, many potential new users look at five axis technology with caution. Adding that fifth axis drastically increases the level of complexity and programmers have to now consider things that they may not have needed to consider before. New users can expect a learning curve with five axis, and it’s important to minimize errors during that time, and get a return on the heavy investment made by purchasing such equipment.
Why Five Axis
The biggest benefit of five axis machining is the ability to machine complex shapes in a single set-up. Having this flexibility and versatility gives greater machine throughput compared to performing the job in a series of set ups, and virtually eliminates the time and cost of preparing fixtures.
Another important advantage is the ability to significantly shorten cutting tools, since the head can be lowered towards the job and the cutter oriented towards the surface. Shorter tools automatically mean higher cutting speeds can be achieved without putting excessive load on the cutter, increasing tool life and reducing breakages. This also reduce the tool vibrations typically seen when machining deep cores or cavities with three-axis machines.
What Makes it Scary
When a company makes the plunge into the complex world of five axis machining, the possibility for errors becomes much higher than with three axis programming. Programming in five axes can make some new users a little nervous.
A number of tools are available to make this task less intimidating, like powerful CAD/CAM software, but it’s important to make sure what you have programmed is actually what will run on the machine in the way it was intended.
This is exactly where the post-processor is often the weakest link, but it doesn’t have to be. The post-processor is the ultimate link between the programming software and the machine.
Considerations for five axis machining should not be restricted to a machine alone. It is important to recognize, understand and continuously view multi-axis decision-making as a true optimization process. Also being able to predicatively analyze the exact machine behavior is essential.
A Good Simulation Software Saves the Day
A verification software like CAMplete TruePath is not only able to generate the proper code for the exact machine installed on the shop floor, it is also able to check programs for machine-specific errors. TruePath takes data on the design, the tooling, the fixturing and the machine, and tells you whether the program is viable or not.
A comparison between the real machine, left, and the 3D model right.
As the name indicates it, TruePath represents accurately and exactly what will happen on the machine, taking much of the anxiety out of the programming process. In addition to avoiding problems on the shop floor, various machining/fixturing strategies can be tested without having to physically prove them out on the machines and tie production up.
A profitable investment in five axis machining depends on planning and systems integration. Verification software should support all major CAM systems on the market, and not rely on their built-in post processors. The native data is read directly, post-processed and the resulting G-Code is verified in the machine context.
However, a simulation platform is only as effective as the level of detail it offers. It must support the specific G and M codes required by each machine. This includes advanced features, such as tool center point control for five axis machining, tilted work plane, and any other special function of the controller, as well as the particular machine kinematics. This can only be achieved by directly importing the controller parameters into the post-processor to produce code for the exact machine on the floor.
The core combo of post-processor and verification in CAMplete TruePath is based on the exact manufacturing CAD data used from the machine tool builder to build the machine you purchase. This eliminates the approximations and guesses of using a model designed by a third party.
Transition Made Easy
When purchasing five axis milling machine, you should understand the impact of the post-processor and how to ensure its accurate output in the machine context. Machine shops and their employees should be focused primarily on making parts for their customers, and not being a software developer. Today’s machines have many options and complex logic, and having the peace of mind of knowing your programs will run the way they are intended to, the customer can focus on programming, metal cutting and productivity, and not debugging or trouble-shooting the black box that the post-processor is.
Jack of all Trades, Master of None
Unlike the CAM software company who has to support thousands of machine configurations to different level of complexity, a dedicated verification software focuses only on the machine put on the shop floor. The focus on a particular dedicated solution proves to be beneficial to the end user by providing a proven superior solution that works from the day of installation. And in today’s market, making sure your machines give you the capabilities your competitors don’t have is key to your success.
Jeff Fritsch is product manager with CAMplete Solutions Inc., Kitchener, ON.