UPDATE EDITION 04/2015
Orbital drilling: A circular path for optimum results
Many industries, such as the aerospace industry for example, nowadays rely on composites and the advantages offered by such materials. Among other things, these composites are lighter and more flexible than traditional materials. However, the different properties of these new materials also mean that new machining techniques are necessary. The use of classic spiral drills leads to the formation of cracks and thus to undesirable flaking in composite materials due to the different degrees of hardness of the respective materials. This means that precise drilling is not possible. Orbital drilling provides a solution to this problem.
With orbital drilling, the tool drills into the composite material in a spiral on a helical path. This prevents delaminations and burr formation when the tool leaves the workpiece. The process therefore protects the material and thus also leads to cost savings – particularly for high-quality and expensive composite materials. At the same time, the axial force is reduced to approximately a tenth of the normal force by the orbital movement. This reduces the requirements in relation to the overall machine rigidity and in turn permits flexible realisation of applications on a robot. In addition to enhanced efficiency, the service life of the cutting tools is also increased.
The advantages of this method are clearly evident, for example, when machining carbon fibre composites, which are used in many different applications. These materials have a low mass in combination with high rigidity and are therefore preferred for use in lightweight construction.
If extremely high precision is required when drilling rivet holes in the aerospace industry, for example, orbital drilling is the ideal solution. This is because it is possible to set an extremely precise and stable diameter in the NC program by means of the helical path radius. Our goal is not just to exploit these many different benefits, but to also develop them further. That is why we are continuing development of orbital drilling technology in cooperation with our French agency PRECISE France S.A.S. The product: our motor spindle family Type 4015 DC. A particular highlight here and optimally suited for this application is the Type 4015 DC-R-HSK63 with standardised HSK-63 tool holder.