Simulate the Machining Process
A constant evolution and a true passion for hydraulics: by following these guidelines, Casappa, a leading manufacturer of pumps and hydraulic motors with its headquarters in Collecchio, Parma, Italy, has transformed itself to a group of 1300 employees and a turnover of 227 million euros. The company offers a wide range of pumps and motors for a large variety of applications. Casappa heavily use several software technologies, some of them very innovative and exclusive. Amongst the more traditional applications, beside the classic CAD/CAM used to create NC programs, there is Eureka
, a piece of software developed by Roboris, a small, dynamic Italian company located near Pisa.
The Reality On Screen
Eureka is able to check any NC program within a full three-dimensional simulation of the machine. It offers a simple, intuitive interface suitable for all users, from the machine operator to the R&D department.
Testing before putting the program in the machine avoids the risk of damaging expensive workpieces, broken tools and equipment and even machine crashes, due to programming errors.
Andrea Basili, technical director at Casappa SpA explains how they got involved with Roboris software. "It all began with the development of a post processor for our CAD software. Normally we place several pieces on the tombstone of the machine, but the tool path had to be replicated for each piece. Roboris developed the post processor. After the first meeting with this Tuscany company, we quickly saw that Eureka could be very useful to simulate the behaviour of the machine tool.
For many years now we have been using parametric programs written manually and using uncommon ISO language, very different from today's Fanuc or Siemens. Those programs are often very large, with a lot of conditional jumps and sub-routines. Thus, they are very hard to understand and modify." Casappa's catalogue is organised into families of parts, inside which there are many variants, even hundreds. Each piece is different from the others and the ISO programs are built ad-hoc.
Besides the obvious advantages of the simulation, Eureka is particularly appreciated by Casappa on the training side, because non-highly skilled operators have to manage 20 year old CNC machines. Basili continues, "The software allows us to see on the screen all the movements of the machine, because the entire machining process is perfectly simulated. Although pieces are built with very tight tolerances, parts do not have strange shapes, but a series of removals, drilling, milling pockets, tapping, boring - in all possible combinations.
In other words, the ISO programs can also be written manually. Therefore, a tool which tests the program before putting it in the machine with the certainty that we will get what we see on the screen gives us a great advantage."
Another reason for Casappa to choose Eureka is the possibility to use the software at various levels, starting from the complete simulation of the entire machine with the three-dimensional model of workpieces, tools, spindles, equipment, including material removal. On the other hand, an operator who has worked there for years and knows perfectly the type of work in progress, does not require a detailed simulation.
For example a sketch of the tool, like a simple cylinder, could be enough. Eureka can add, delete or change any kind of tool, defined by numerical values directly inserted in appropriate form, or importing its graphic shape form file. Every tool of the company can be stored in a database and retrieved when required.
Basili confirmed that, inside Eureka, it is very easy to modify the ISO code. "Macro, cycles, sub-programs, the simulator executes the G codes and acts like the real machine. Axis position, the state of variables, offsets and any other simulation parameters can be monitored in a status window. It is a powerful debugging tool. Moreover, an accurate simulation allows an estimation of the cycle time. Our technical office can check if it is compatible with the desired time and if the movements of the machine are optimised and so on."
Even the Robot Becomes Virtual
Mirko Sgarbi, Administrator of Roboris, emphasises the ease of use, the quality of G-code interpreter and the flexibility of the software. "Eureka can be easily customised at any level and it requires only a short training course. Excluding some 3D data importers (CATIA, SOLIDWORKS
, Inventor, Iges, Step etc), the software is entirely developed by Roboris and this gives us full control over the software."
In addition to the NC verification, Eureka has other modules that transform it in a visual post processor both for CNC machines and robots. In this case, the input is a machine-independent APT file and the output is the machine program in its controller language. Roboris has developed its own technology (Robot Milling) that allows you to treat an anthropomorphic robot as a CNC machine tool The strength of the software is to be not only a post-processor.
Eureka processes the APT calculating the best robot positions that satisfy the CAM requirements. In the meantime it checks for out of limits, singularities, material removal in rapid and collisions. If errors occur, powerful but easy-to-use interactive tools aid the user to overcome the problem. The same with external axes and in reverse mode with the workpiece mounted on the robot.
Even machining with blade cutters using all the degrees of freedom of the robot can be performed. At the end, when everything has been tested, Eureka generates the robot program (ABB, Kuka, Fanuc, Motoman, Staubli, Kawasaki, Comau) splitting huge toolpaths in smaller programs to fit the controller memory requirements.