Most of the five-axis “magic” is managed by software in the CNC control and CAM software systems. The machine tool should be selected for sizes, speeds and capacities. And five-axis machine costs are coming down, and quality is improving with the implementation of CAD and simulation in the design process.

However, there are a few interesting software functions that help to make five-axis programming economical.

Most CNC controls have a utility function called tool center point management. Depending on the control manufacturer, this function may be named RTCP, TCPC or TCPM. The utility performs many functions with similar behavior no matter the controller. The key function performed by tool center point management systems is to allow the CNC control to accept fixture offsets and adjust NC data—on the fly—while working in five-axis mode; thereby, allowing one set of post-processed data to work for an entire batch of parts.

The benefit is that an operator need not align a workpiece precisely to the rotary table centerline. A part can be mounted and probed, and the offsets from center can be loaded into the control registers and processed with the NC data during operation. This function can reduce idle time on a milling machine while mounting a part and have the machine tool focus on chip removal. This is a more economical approach than purchasing a secondary pallet and table to allow part mounting while the part on the first pallet is being machined.

Taken one step further, the tool center point management allows a series of parts to be mounted without being precisely located on the machine or without being precisely mounted relative to the remainder of the production lot. So not only can we reduce the labor for mounting parts and the machine idle time, this control function can reduce the cost and preparation time for mounting fixtures and otherwise non-critical mounting surfaces on the workpiece.

In addition to software impact on the economic return from the CNC control system, the CAM software used to generate NC code can greatly impact the performance and economics of five-axis milling. A cursory review of CAM software from the Internet or brochures, or at a major trade show, indicates that nearly all market participants offer five-axis technology today.

So how do you then choose a CAM software product? One factor might be price, and this would seem consistent with a view toward economic implementation of five-axis technology. However, the retail price of a software package is only a first cost and is not the true implementation cost. Studies have shown that the license fees may comprise 25 to 30 percent of the actual implementation costs, with the remainder attributed mainly to training costs and ramp-up costs (inefficient labor utilization until a user is fluent and performing with high productivity).

On this basis, the evaluation of software products may be very different. For example, some enterprise products have up to four weeks or more of training duration and may require additional systems consulting work. And this general training format may not guide a user’s implementation on their particular products and applications. A simpler system may be quick to learn, but the user may struggle to get good results from the system or not have technical capability to control the cutter as desired.

But the larger impact on economic implementation of five-axis machining may be in the technical details of the selected software. Though nearly all software offers five-axis capaiblities, not all software is created equally.

Many customers take months or more to evaluate five-axis software products. So the answer to the question will not be found in the next few paragraphs. Each organization will have different requirements and will weigh various factors differently. But we list some key questions that can help guide a prospective purchaser to select an economical five-axis milling solution.