Hastings-based Hivac Engineering is a well-established specialist in the manufacture of ultra-high vacuum chambers and equipment used in surface science, semi-conductor and synchrotron particle acceleration. For the latter think CERN and the Large Hadron Collider in Switzerland, or closer to home Diamond Light Source in Oxfordshire.
The type of work that Hivac Engineering undertakes, therefore, is generally low-volume, R&D, but to extremely tight tolerances on large components.
Many of the products manufactured by Hivac Engineering are welded assemblies, made up from a number of machined components, some of which are straightforward, others can be complex. This work is a mix of made to drawing and in-house design, where it employs 3D CAD and Finite Element Analysis. A common thread throughout, though, is the finished accuracy of the welded assemblies, which have to be finished machined, creating a requirement for large capacity, and accurate, machine tools. “Our investment in machine tools is driven by market requirements, if we need a machine we will buy it, but due to the nature of our work, the majority of it being stainless steel, but we also machine refractory materials such as tantalum, molybdenum and high temperature ceramics, such as Boron, Macor and Shapal. As a result we need robust machines that are capable of not only accommodating the parts we make, but also of being able to achieve the quality of machine finish that our customers and products require,” says Paul Lennard, Managing Director, Hivac Engineering.
Investment in machine capacity at Hivac Engineering backs up this point with a heavyweight XYZ 2010 vertical machining centre and an XYZ XL 1100 extra-large lathe being the most recent additions. Key to the decision to buy the XYZ 2010 VMC was its construction, which features a solid cast base, rather than a fabricated one. This 20,000 kg machine provides Hivac with a robust machining platform, added to which is the standard 1000 mm travel in the y-axis, which when combined with the 2000 mm and 800 mm travel in the x and z axes creates a large machining envelope, yet the footprint of the machine is relatively compact for a machine of this capacity. Hivac also took the 4 th axis option with the machine as well for even greater versatility. “We need machines that are capable of machining straightforward and complex parts, and with the XYZ machines this is what you get. This is helped by the use of the Siemens ShopMill 828D control system, which we find extremely easy to use thanks to the conversational programming and operators who are unfamiliar with it quickly get up to speed.”
Changes in personnel and production requirements were also a driver in the choice of the XYZ XL 1100 lathe that was installed in October 2015. Much of the large diameter turning work at Hivac Engineering had been done on manual machines and due to the skill requirement for this work this was becoming a bottleneck. This led to Paul Lennard looking for an alternative and the criteria for the lathe was much the same as for the machining centre, it had to be robust, easy to use and have a relatively compact footprint. “The XYZ XL 1100 met all those criteria as it is an 8000 kg machine, with a solid cast construction, with the bed length that we specified the footprint is only 3930 mm by 2300 mm by 2200 mm, but we can swing 1100 mm over the bed.”
The XL 1100 makes use of the Siemens 840D control, in this case with the ShopTurn variant. Both the ShopTurn and ShopMill controls make use of Siemens JobShop Concept that simplifies all of the on-screen prompts ensuring that programming is quick and easy.
Confidence in the resulting program is enhanced by Siemens’ Line trace graphics that allow the operator to view the program as it progresses through each stage of the cycle, with full 3D graphics assisting the process. “When it comes to investing in machine tools we generally know what we want and with XYZ Machine Tools we know what we will get. The machines are well constructed, the service and support is excellent and we feel that we get looked after. We must do as these latest two machines take our XYZ plant list to nine machines now, a mixture of five CNC lathes and machining centres with the Siemens control and four ProtoTRAK controlled mills and lathes,” says Paul Lennard.