22/07/2008 -
Multifonction machines (often called mill turn machines) are nowadays a very profitable investment for many companies. Mill turn machines are capable of combining milling and turning operations and can thereby machine complex parts in just 1 operation. It is important to realise, however, that these machines require not only specialized and highly trained staff but also a CAD/CAM software adapted to mill turn machining which enables the simulation and synchronisation of different machining stages when the machining program is generated on the computer. 2 major reasons behind the success of these mill turn machines are :
- The possibility to machine parts in just one operation greatly reduces preparation times. Often long preparation times lead to high costs especially in the production of small series.
- Mill turn machining guarantees higher precision machining as it is not necessary to machine the part in several operations which implies less handling of the part during the different machining stages.
These 2 factors offer a competitive advantage for many small sub-contractors who manufacture very complex, high precision parts in small series of 1-100 parts.
The need to choose the correct CAD/CAM software The purchase of sophisticated machining centres is a very important investment for companies and represents a big challenge for these companies: Modern machining centres and mill turn machines are very expensive and in many cases need to work 24h a day so that the investment is profitable. In fact this is one of the main reasons that companies stop direct programming on machines. In addition, machines are often equipped with numerical controls that operators do not know very well. One of the main reasons however why companies stop direct programming on their machines is the complexity of multi-axes machining using 2 spindles which makes mental calculation of different operations impossible. The right CAD/CAM software is therefore essential to get the most out of your mill turn machine. In many cases companies spend alot of time choosing the right machine but they only think about the software afterwards. "Not too long ago I spoke to a prospect who programmed his Index G160 machine with a text editor. Seeing as he could not simulate his programs his machine preparations times were as long as 80 hours depending on the part. This is too long and a company making small series cannot survive with such preparation times." Another important reason for the use of a CAD/CAM solution stems from the diversification of machines now used in companies. Many companies now use several machines from different machine tool manufacturers but wish to use the same software to program these machines. In addition, using a "neutral" software to program has another advantage - the same program can be used on different machines to better exploit all company machines. «TopSolid'Cam has functions to allow the transfer of a part completely programmed on one machine to another and to adapt the machining" explains Mr. Heinemann. "I don't need to change the machining program, all I have to do is adapt it with the right post-processor."
Turning expertise One of the key competencies of a CAD/CAM software for complete machining is its capacity to manage milling and turning. The majority of software solutions on the market today offer very strong milling strategies but are less competent in turning. Missler Software in fact developed very strong competencies in turning from early on and today is one of the leading providers of CAD/CAM for turning. Many TopSolid customers chose TopSolid'Cam because of its strong turning capacities. In TopSolid'Cam turning operations the part is put on a virtual machine and the software proposes adapted machining cycles. In addition, TopSolid'Cam indicates which operations can and cannot be carried out with the chosen machine. This differentiates TopSolid'Cam from other software solutions which do not have integrated simulation capacities. "TopSolid'Cam does not simulate a machine like in some software solutions, it programs a virtual machine which thereby enables the operator to verify and control the toolpath during programming." Another strong point of the software is the possibility to manage the stock so that all machining operations take into account the correct stock model.
Realistic machine environment The quality of the post-processor determines if the machining simulation reflects what really happens on the machine. The generation of high-performance post-processors necessitates a deep understanding of machines and numerical controls. Missler Software and its resellers work closely with the principal machine tool manufacturers on the market "Depending on the numerical controls used there are many different settings which can mean that a post-processor works perfectly on one customer site but not on another." Tool modeling is also very important and may be considered as being as important as machine modeling. In order to generate correct simulation results all tools used need to be represented as accurately and realistically as possible. All operators should be able to represent their tool and tool paths in the CAM software. TopSolid'Tool offers a good tool database and responds to the needs of most TopSolid'Cam users. For more detailed tool databases Missler Software has developed interfaces with external databases such as Gedix, Tool Expert and Walter TDM.
Maximise productivity Simulation in mill turn machining does not only concern avoiding collisions. Taking into account time and cost constraints it is also important to synchronise machining operations in terms of spindles and different axes. Starting with the values in the tool database and tool change-over times TopSolid'Cam calculates the length of the operation very precisely and graphically represents the machining sequences. The operator can interactively shift the operations in order to obtain a balanced repartition of the tools. TopSolid'Cam indicates when certain operations cannot be shifted because the tool is already being used. In order to really get the most out of your mill turn machine you need to reunite the following criteria: trained and skilled staff, a well-adapted CAD/CAM software capable of simulating machining operations, good support from the CAM developer who is familiar with the machine tools on the market and is capable of using this knowledge in the software and post-processors. A company that is capable of meeting all of these criteria will benefit from important productivity gains, especially for the machining of complex parts in small series.
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A CAD/CAM software is essential to program complex multifunction machines Download imag |