With increasing costs and demands, companies must make use of advanced software products. How CAM can support your company and keep you competitive is outlined in the following.
Companies that do not manufacture products directly but instead manufacture mould and die components, or tooling face increasing time and cost pressures. As the quality of a huge number of cast parts depends on a single mould, there can be no doubt about it: quality is paramount in this industry. Approximately 3,800 tool and mould manufacturing companies in Germany are facing up to these challenges and rely on optimised manufacturing processes more than any other industry.
Injection moulds, die cast moulds and punching and shaping tools are key components for the production of sheet metal and plastic components used in the automotive and commercial products industries and more. Tool and mould-making is a key industry that makes a lot of other things possible. In order to produce tools that are efficient and stable in production in the long term, tool and mould-makers use state-of-the-art machines, cutters and software wherever possible. Especially when it comes to CAM software, you will find ‘power users’ in this industry. Dimensional tolerances are often under 5 μm and surface qualities for visible parts under 1 μm, as well as the challenge to achieve this in the shortest possible time, call for sophisticated machining strategies.
The need to protect cutters and machines becomes particularly obvious when we consider that the hardness of the materials used for forming and injection moulding tools is rarely less than 60 HRC, with even higher values for punching tools. The manufacture of graphite electrodes for die-sinking is another demanding task in the industry for which CAD/CAM systems such as Hypermill must provide special solutions.
Global mould and die making companies are in competition with market players from low-wage countries, among other competitors. Accordingly, they are subject to high cost pressure and have to focus on increasing productivity. High-speed cutting (HSC) and high-performance cutting (HPC) reduce processing times as well as set-up and erosion times. Multi-side machining of mould plates and inserts reduces set-up times while also increasing accuracy. 5-axis simultaneous machining also allows areas that are hard to reach to be milled, which avoids time-consuming erosion processes. Mould and die manufacturing has small lot sizes to increase pressure to obtain good results the first time. The CAM software also has to provide high process reliability through robust tool paths, collision checking and simulations. Highly reliable processes are a prerequisite for night and weekend shifts with reduced manpower.
Open Mind ensures consistent workflows with its data connection to CAD systems at the beginning of the workflow and its own postprocessors at the end, according to the company. But functions for accelerating programming are also important. Hypermill offers numerous automation options, such as feature and macro technology. In addition to the assigned geometry, production-relevant information, such as the surface, depth, or starting point, is automatically recognised and transferred to the CAM system. Processing sequences and thus programming know-how are stored in macros and a macro database. Users can call them up at any time from there. Macro technology allows users to complete NC programming in record time. This includes, for example, prismatic mould plates with all of their 2.5D geometries and many holes for cooling systems.
CAD for CAM
With Hyper CAD-S, Open Mind has developed its own CAD solution specifically for CAM users. Efficient programming is of primary importance and perfectly supported by the CAD system, the company promises.
The parting plane between the mould plate on the nozzle and the clamping side must be completely sealed during injection moulding to ensure that no seams are visible on the end-product. This requires sharp, intact edges. Hypermill provides the ‘Automatic face extension’ function to ensure this. It allows the periphery of selected milling surfaces to be extended during programming. Thanks to this CAD for CAM functionality, it is no longer necessary to modify the milling surfaces in the CAD system beforehand. As a result, this saves programming time and achieves a better milling result.
Open Mind is implementing more and more functions for processing CAD data for further process optimisation in CAM programming. The Hyper CAD-S function ‘Global fitting’ is therefore directly integrated into the CAM strategy in 5-axis tangent machining. This function allows multiple faces to be joined into one face with a defined ISO orientation.
Own electrode module
Another example of the high degree of automation is the electrode module. With Hyper CAD-S Electrode, the electrodes can be derived from the CAD data and then used to create the NC program for milling copper or graphite electrodes using predefined machining macros. All necessary technology and component data for the EDM process is automatically transferred to Hypermill, Open Mind explains.
Thanks to special strategies for high-precision machining, subsequent process steps can be eliminated. The ‘High precision surface mode’ option ensures ultra-smooth surfaces with tolerances in the µm-range. This means that tool and mould-makers can save themselves the trouble of re-polishing. The ‘Smooth overlap’ function has the same effect to improve the machining result at the joining of two machining regions (same or different cutter) or at steep and shallow area boundaries. A perfect, imperceptible transition to the adjacent surface is achieved by lifting the tool slightly.
Open Mind has a strong focus on 5-axis technology. Hypermill offers a wide range of high-performance 5-axis strategies. 5-axis machining makes it possible to machine challenging geometries, free-form surfaces, and deep cavities far more efficiently. One example of this is 5-axis rest machining with automatic indexing. This strategy independently determines the positions and areas that allow the part to be completely machined in a single operation. And having less dynamic axis motion is especially important on large milling machines. The easy-to-program 5-axis shape offset roughing and finishing is ideal for 5-axis simultaneous complete machining of form inserts and their curved faces. The Hypermill Maxx Machining performance package offers innovative strategies for drilling, roughing, and finishing. The package contains efficient solutions especially for the special challenges in mould, die and tooling applications. There are often pockets on mould bases and inserts. It is possible to reduce the amount of time required to rough them significantly, as the Hypermill Maxx Machining HPC roughing module is optimally suited for the task, according to the company. This strategy works with spiral and trochoidal tool movements, resulting in optimal milling paths, maximum material removal, and the shortest possible machining times. Perfect pocketing technology ensures the best possible utilisation of high-feed cutters. An intelligent algorithm fits the largest possible pocket into the area to be roughed and automatically generates optimal toolpaths for high feed machining. Linear and contour-parallel toolpaths are optimally linked to guarantee rapid production.
The right tool and the right strategy
Open Mind developed innovative tool path strategies for planar and other large radius of curvature surfaces. These strategies are enabled with conical barrel cutters, also known as arc-segment or circle-segment cutters. These cutters have very large radii and thus enable significantly larger step-over distances compared to ball endmill. Particularly machining steep or flat planes using the conical barrel cutter ensures enormous time savings using the Hypermill Maxx Machining finishing module. This results in optimal surfaces, extended tool life, and significant time savings of up to 90 % in comparison with line-by-line milling using ball mills.
Other examples of performance-enhancing special functions of the package: barrel cutters are used efficiently for finishing prismatic fillets. An extremely high feed rate is achieved through this plunging and pulling machining. The tilted barrel cutter is used according to the principle of high feed rate cutters in this strategy. ‘5-axis helical drilling’ is well-suited to open bores or starting holes in pockets for difficult-to-machine materials. The milling tool plunges into the material quickly, without the need for predrilling. Intelligent 5-axis orientations of the milling tool ensure friendly machining and safe removal of the chips.