Self-programmed machining cycles speed up hydraulic cylinder manufacturing
Dedicated NC programmer makes full use of onboard CNC resources and boosts productivity of component manufacturing
Niko Streicher is a CNC programmer at Neumeister Hydraulik. He recognized that similarly structured CNC program sequences are used for manufacturing different cylinder types and he combined them to create his own user cycles. The result was a significant reduction in time and greater flexibility.
Customized hydraulic cylinders
Neumeister Hydraulik, a company based in Neuenstadt near Heilbronn (S. Germany), develops and produces customized hydraulic cylinders for mobile and stationary applications, along with the associated assemblies, control systems and valves. Although these sophisticated products are mostly assembled by hand, fully automatic welding robots and CNC machining centers are used to manufacture the components.
Components for hydraulic cylinders are made in relatively small batch sizes. The hydraulic experts usually create the required CNC programs directly on the shop floor. The CNC programmers therefore play a dual role of technology expert and machine operator for the actual machining process.
Paying attention pays off
Niko Streicher is one such all-rounder at Neumeister Hydraulik. While he was working at a turning/milling center, he noticed that similar machining steps crop up again and again in many production jobs.
Unfortunately, the turning, milling and drilling cycles offered by machine and CNC manufacturers cannot be used for these very specific machining tasks. For this reason, time is often spent rewriting these routines in existing CNC programs for use with the new component.
The familiar CNC programming ...
To create the user cycles, Niko Streicher got to grips with the highly flexible CNC high-level language programming step by step. The high-level language in SINUMERIK Operate basically consists of an extensive set of programming commands that can be used as normal G code in the CNC program. In other words, they can be used in CNC subprograms – or CNC cycles, as they are referred to in technical circles.
... plus program branching and user variables
The set of SINUMERIK high-level language commands provides control structures such as "IF-ELSE-ENDIF" and other conditional program branches that are typical for high-level computer languages. It's also possible to define your own variables. This provides the basis for systematically implementing complex manufacturing tasks in structured CNC programs. Solutions can be developed for manufacturing tasks which stretch classical G code programming beyond its limits.
„Learning by doing“
While he was programming his first user cycles, Niko Streicher realized that learning by doing is also possible in the case of SINUMERIK high-level language programming. And initial testing of his own user cycles made it clear that the idea was working. However, a new challenge presented itself.
The own user cycle: ready. And how to operate?
A CNC cycle also has to be supplied with values. And more complex manufacturing tasks usually require a large number of parameters. Generally speaking, these can be entered directly in the program code of the calling CNC program. However, this procedure is not particularly user-friendly and is also prone to errors. Not only that, the required paper documentation is completely unsuitable for the harsh manufacturing environment.
It was clear to Niko Streicher that the CNC cycles he had created could only bring about real benefits for his day-to-day work if they could be used really simply and without any errors.
Intuitive input of parameter values via user-defined input screens
SINUMERIK offers an additional onboard resource for the convenient and intuitive input of cycle parameters: machine users can create their own input screens for automatically entering parameter values in the calling main CNC program. The script language used here is the same one that is used for the input screens of the SINUMERIK technology cycles.
Niko Streicher used this script language to define screen forms for his own CNC cycles. These input screens use the everyday terms and concepts familiar from component manufacturing at Neumeister, and they also contain graphics to illustrate the precise meaning of each of the parameter values.
Happy co-workers – and noticeable time savings
The colleagues who work on the machines with him were impressed. They immediately and intuitively understood the strategies of the new cycles thanks to the input screens that reflected their everyday work practices. Niko Streicher's new user cycles significantly reduced the time required for preparing and running in the machining process, as well as the machining times themselves. And, as he points out himself, the transparent cycle parameters make it possible to assess their effects more easily, and to optimize the machining process faster than was previously possible.
My own user cycles allowed me to handle recurring CNC programming tasks more efficiently. And I could create them directly at the machine, as the tools for creating cycles and input screens are integrated in the CNC.Niko Streicher, CNC programmer at Neumeister Hydraulik
It's all there – you just have to use it
The CNC high-level language has turned out to be a valuable means of boosting production efficiency for keen and motivated machine users. User-defined cycle screens are the icing on the cake here, as they ensure that the productivity increase gained by the user cycles is also user-friendly. All the necessary tools are available onboard the SINUMERIK CNCs.
Author: Andreas Groezinger