Oct 18, 2011

SolidCAM iMachining halves cycle times and makes cutters last 5 times longer for mill-turn operations at Dixons Surgical

Since 1948, Dixons Surgical in Wickford, Essex has been manufacturing reuseable surgical instruments. As the market has matured, Dixon Surgical has now progressed to making more complex orthopedic instruments, modelled in CAD. These changes encouraged the company to invest in both SolidWorks and SolidCAM, including its revolutionary iMachining module.

Jay Dixon, Managing Director says, “We have been using CNC machining since the early ‘90s. Programming was either manual or on-machine conversational. Now we have standardised on Mazak machines, including a Quick Turn Nexus 200 MSY, which has milling, Y-axis and sub spindle, and a VCN 410A vertical machining centre. During 2010 we started to get requests for parts which were difficult to program on the machine, especially the mill- turn, and which were already modelled in 3D, so we started to look for a suitable CAM system.”

Dixon Surgical had already invested in SolidWorks from Cadtek Systems Ltd, so it was looking for a package which would integrate with it and which would also be able to program its mill-turn machines. Jay Dixon continues, “We rapidly appreciated the benefits of 3D CAD for both new and existing parts. The parametric tools inside SolidWorks allow us to model just one part of a family of parts and, with a parametric table, automatically create the multiple versions, common in our industry. Our two main criteria for a CAM system – seamless integration in SolidWorks and the ability to program our Mazak Quick Turn Nexus - eliminated every system we looked at, except SolidCAM.”

SolidCAM is fully integrated inside SolidWorks and allows Dixons Surgical to make just one machining program and use the CAD system’s parametric tables to produce the other variants. Jay Dixon says, “A Ring Fixator instrument we make comes in 12 different sizes and, with other CAM systems we would have had to create a separate model for each variation. SolidCAM really extends the reach of the CAD system. It enables us to design and manufacture the jigs and produce the CNC program for each of the three operations required to machine each Fixator from one CAD model and one CAM program, compounding time saving on top of time saving. It really impressed our machinists when they realised amount of duplication of effort they had avoided!”

Following an impressive demonstration, Jay Dixon realized that the new SolidCAM iMachining module could make a big difference to the ease of

machining on his Mazak Quick Turn Nexus, as it solved the problems of rigidity and efficient metal removal for milling operations on the machine. He says, “For C-axis milling you often have to compromise on the tooling you select, using longer projections than are ideal. Furthermore, mill-turn machines are not as rigid as a machining centre, have less power and the work holding is more flexible, with longer overhang situations than one would like. SolidCAM iMachining has produced some incredible results on stainless steel, machining times are half of what we expected and the cutters last about five times longer than they did previously. We were used to getting unpleasant noises from the machine as it was cutting, but now we just get a sweet milling sound.”

A stainless steel spinal implant instrument, which Dixons Surgical manufactures on its Quick Turn Nexus, has a turned outside profile with milled sides, and a through pocket in the centre, 26mm deep, both of which need to be cut using driven tools. The central pocket is cut with an 8mm long-series carbide tool and finished with a 6mm tool. iMachining enables this pocket to be cut in one pass at full depth, starting from a pilot hole, without vibration. Jay Dixon says, “With traditional methods we would have had lots of steps down the machined walls. With iMachining we get a lovely smooth and flat finish.”

Programming in SolidCAM is also easier. Dixons Surgical employs highly skilled engineers, so machinists are able to prepare their own programs, while the machines are cutting. Jay Dixon says, “With on-machine programming of complex parts, we would often have the machine tool idle for one or two days while the CNC program was being perfected. With iMachining it just produces code which works first time, hugely increasing productivity by giving us more machining capacity and virtually eliminating programming and setting time. We feel our future is in producing complex orthopedic instruments. We already have the experience, skill and knowledge required to finish surgical instruments to the required standard. Our investment in SolidCAM and iMachining is a crucial part of our expansion plans. We have been blown away by its performance.”