Turning on CAM technology

May 1, 2002
Advanced turning systems demand targeted CAM software and high-end operator training.

Advanced turning systems demand targeted CAM software and high-end operator training.

Effective CAM Systems for multi-axis mill/turn operations, such as ESPRIT, supply an ANSI/ISO-coded library for regular turning tools, inserts, and holders, as well as a full suite of milling tools for three-axis C and four-axis Y mill/turn operations.

The ESPRIT Sync List, which features a barchart displaying cycle times for each operation, is also connected to simulation and post processing; thus, users can view each canned cycle and all the tooling.

The upside to advanced turning machines is that they have high-end capabilities that make them useful and valuable to a wide range of manufacturers. But to truly cash in on a machine's functionality, shops need advanced software and trained operators. Otherwise they may face a bevy of problems like slow programming and setup, dulled-down machine capabilities, and limited part-production potential. When it comes to CAM software, advanced turning machines need systems that support their complex functionality. Software, therefore, has to understand specific machine-tool-configurations and features like turrets, spindles, synchronization, live-tooling parameters, and parts-handling issues. It is also critical that the software defines toolpaths for the machine's advanced turning and part-handling functions and performs accurate toolpath simulation and verification including interference detection and realistic display of machine components. In addition, the CAM system should produce quality NC code from the postprocessor that does not require manual editing and takes advantage of an advanced turning machine's special code requirements.

And it doesn't end there. In a perfect world, the CAM system drives any combination of axes, supports all of a machine's canned cycles, and has a complementary set of canned cycles to supplement the control. But the final requirement is the real trick — end users want a system that is easy to use and program. That's because they know the challenges they face when training operators, and how important training is to the success of their operations.

This is the reality for end user Tim Fennell, Art Director/CNC Programmer at Quality Aspirators (QA), Duncanville, Tex. His company uses Citizen L32 and M32 Swiss-style lathes to produce surgical suction tips for the dental industry.

While Fennell touts the importance of a CAM system's features, he says it is having a trained operator who understands both turning machines and CAM systems that ultimately lets the shop tap into advanced capability. "Obtaining a working knowledge of the advanced turning machines and the CAM software helps surmount functionality problems," he explains. "These machines are capable of performing multiple operations with the same tool by simply changing the mode or placement of the code within the program. Almost every part has multiple ways in which it can be produced. Deciding which one gives the best results requires a working knowledge of the machine and its modes, along with putting that logic into your CAM software so that correct code is output."

Even a highly trained operator can encounter programming challenges when entering code for part machining. And if part programming is complicated, usually so is machine setup. That's why most shops use advanced turning machines for longer runs.

This is the case for L&P Machine Products, a division of Legget & Platt (L&P) of Carthage, Mo., that manufacturers engineered products and is planning on implementing long runs on its Mazak Integrex lathe with live tooling. Programming times will inspire L&P to work with long runs, but part complexity will dictate in the future whether or not the machine is programmed by operators or CAM programming takes place.

Randy Rauh is president at CIM Integrators Inc., Owasso, Okla., where he has sold and serviced CAM software for the last 14 years. Slow programming is an issue he understands, and he blames the long-run-machining trend on sub-standard CAM technology.

"Due to some backlogs from CNC programming shortfalls, we see machines mostly used for long runs. However, when the CAM technology is successfully implemented, these machines handle a broader range of part quantities."

Successfully implementing the proper CAM technology is complicated, but doable, according to Rauh. The problem, he says, is that users rely on on-board conversational programming instead of off-line CAM programming.

"G-code programming of advanced turning machines is sometimes too difficult for most manual CNC programmers. Most CAM systems offer only minimal support for these machines; therefore, a majority of those programming advanced turning machines rely on on-board conversational programming. The problem with this is that, in most cases, conversational programming does not take advantage of CAD data. As a general rule, the machine is usually sitting still while conversational programming is taking place. This means shops relying on conversational programming at the machine spend more time in overall setup than those using an external CAM product. Shops should do whatever it takes to keep the spindle turning, and programming off-line with a CAM system can lead to higher productivity."

Short story success
QA's Fennell has taken to his system's ease-of-use and functionality to such a degree that he uses his advanced turning systems for short runs on prototype work and new designs. According to Fennell, setup of the machine simply requires inserting the new tool and "touching that tool off to the diameter of the stock."

When it comes to a CAM system, he reports, "Using ESPRIT CAD/CAM software, I produced parts and prototypes that used the advanced features of the L32, even with no machining background. On the Citizen, much of the functionality has been made extremely easy. If I program a front drill/turn/tap routine and later decide to do that routine as backwork, I simply cut-and-paste the code to the new area, and change the tool numbers with no further programming."

For Fennell, learning how to manage his CAM system and his turning machines meant under-going thorough training on both the CAM and turning systems. The manufacturer of Fennell's CAM system was an integral part of that training, as was the machine tool manufacturer.

"With the help of our CAM supplier and machine tool representative, we were drawing, posting, and making parts within a few days of machine installation," he remarks.

Machine tool dealer Don Thompson feels that all parties with equipment dedicated to the production process should be involved with the training. He works as an applications manager at Joachim Machinery, Torrance, Calif., which sells machine tools like Okuma CNC lathes and mills and Wasino mill/drill lathes.

"Some of the biggest obstacles faced by turning machine customers, like programming the milling capabilities and balancing cycle time between both spindles, are resolved by training," comments Thompson.

Chuck Mathews, Vice President for DP Technology, a CAM software developer from Camarillo, Calif., supplies Fennell's ESPRIT-CAD/CAM software system. He agrees with Thompson and adds that when users don't get the most out of their advanced turning operations, it is sometimes a matter of a poor CAM system and often a matter of poor training. "Most customers do not use their machine to its full potential due to limitations within the CNC programming group, skill levels, lack of training, and insufficient capability within their CAM system."

He lists employee skill level and time allotted for training as the top two issues end users need to address to ensure successful advanced-turning operations. But understanding how to train is also important. In regards to that issue, he reports, "Students must learn the fundamental principles behind the technology. For example, to program a machine tool, one must be well-versed in geometry and trigonometry, so that he/she can truly under-stand the coordinate system a machine uses — Z, X, C, Y, and B."

Rauh's training philosophy is in line with Michael Stratton, CNC programmer at L&P. They both feel that actual machine experience is equally important to a working knowledge of geometry or trigonometry. And future operators have to train on the machines they will be working with.

Can't we all just get along?

CAM manufacturers need to make sure their software is keeping pace with advanced-turning functionality, or else it becomes useless and outdated. The best way to do this is to work with machine tool builders to best meet end user needs.

It sounds easy, but it's not just a matter of getting together once a year. Instead, it's a true collaboration, which can be a fairly involved process. Thompson points out that CAM developers must work with machine tool builders to develop post processors that can handle machine capabilities. Mathews, as a CAM manufacturer of ESPRIT, similarly calls for a "coordinated relationship" in order for "CAM software and machine tools to perform together in an optimum fashion."

But Rauh, an ESPRIT reseller, explains that while there must be a constant dialog between the CAM vendors and machine tool developers, establishing that dialog is not simple. While CAM vendors offer their technology to multiple machine tool builders, the builders are oftentimes more exclusive with their partnerships.

"Machine tool manufacturers must adopt a policy of cooperating with CAM vendors and work with them when they release new technology to the marketplace. CAM vendors don't limit their support to only one brand of machine. So why would some machine tool manufacturers pin their hopes for a CAM solution to best showcase their technology on one CAM vendor?"

Despite industry politics, Fennell at QA knows what would help his shop optimize operations. He would like to see the relationship between the CAM vendor and machine tool manufacturer go a step further.

"I would like to see CAM software developers include the posts for advanced-turning machines along with examples and tutorials of sample parts for that particular machine, showing how to set and use the software in different situations. This means the software developers will have to understand the logic of the advanced turning machines and include that logic in the post along with enough information and examples to show the end user how to take advantage of these features."

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