TURNING DESIGNERS INTO MACHINISTS

By using a feature-based programming system, this British metrology specialist shortened their overall development cycle and gained more freedom to experiment with novel ideas that can be investigated more quickly and convert prototype quantities to full-scale production.

Metrology and healthcare specialist Renishaw (Wotton-under-Edge, UK) has been able to greatly improve the productivity of its rapid prototyping department by turning its designers into machinists. The key to the transition was the introduction of FeatureCAM, a feature-based programming system from Delcam plc (Birmingham, UK), in place of the department’s previous CAM software.

“It is important for designers to appreciate the manufacturing techniques and capabilities that are available to them . . . this helps facilitate good ‘Design for Manufacture’ as well as reduce any unnecessary delays during the prototyping stages of manufacture,” explained senior CAM development engineer Richard Turner.  To achieve this, Renishaw has always encouraged designers to take a ‘hands on’ approach, even providing two Nexus machine tools from Mazak Corporation (Florence, KY) for them to use for tooling and prototyping production.

“However, the designers, being occasional users, found our existing CAM software too difficult to use so they all passed the work over to our small batch department or sent their designs out for machining. At times, it was taking up to six weeks to produce prototypes, which was obviously having a negative effect on our product development process,” noted development engineer Chay Allen.

The move to FeatureCAM began after another development engineer, Tristan Dover, visited the Delcam stand at the MACH 2008 exhibition. “I saw a five-minute demonstration that made FeatureCAM look like the easiest CAM system I had ever seen. I downloaded the evaluation version and could remember enough from the demonstration to use it. Even without any training, I could program as quickly as an experienced user on our existing system in a head-to-head competition. I realized that this software would be ideal for our designers and other casual CAM users.”

“Since we have adopted this new software, staff with little machining experience can be trained to use the software in a day,” claimed Turner. “Even more importantly, this software is so intuitive that they can come back to it after a two-month gap and are still able to use it.”

“We have set up our system with the standard tooling package that we use on the Nexus machine tools and we have added in the speeds and feeds appropriate for our range of materials; this has made the system almost completely automatic,” remarked Allen.  “Some of our designers have no experience selecting tooling or feed rates, all things that come with experience, but with this software that doesn’t matter because the system makes all the tooling choices for you,” added Turner.

After the success with this new system, Renishaw engineers began using PowerSHAPE CAD software for prototype tooling. “Most of the plastic parts are fairly small and we only need a few examples, so we developed a system where new inserts could be used in the same tool assembly,” stated Allen. “With PowerSHAPE, we can quickly develop the core and cavity from the part design and then machine the shapes into our standard inserts with the new software.”

The benefits to Renishaw have come from a shortening of the overall development cycle since prototype parts can now be produced in a day or two. The designers have more freedom to experiment because these shorter lead times mean novel ideas can be investigated more quickly. Furthermore, because the designers must think about manufacturing at an earlier stage in the development cycle, it is easier to convert from prototype quantities to full-scale production.

The only problem has been for the rapid prototyping team: Whereas the machine tools were usually available before, now the demand from the designers has now grown so much that the team’s own engineers often can’t get access to them.

Delcam plc, Small Heath Business Park, Birmingham, B10 0HJ, UK, 44 (0)121 683 1081, www.delcam.com.