May 7, 2003 -- Hampshire based engineering company Rimor Ltd. chose to install two seats of NC Graphics DEPOCAM after an extensive evaluation of other CAM systems. They employ over 100 people at their 35,000 sq. ft. factory in Denmead. From here they serve the motor sport, aerospace, oil and gas and the semiconductor industries, making specialist equipment utilising the cleanroom facilities they have onsite. They focus on low volume and higher value components through to complete supply of modules and assemblies.
Problems with importing and manipulating IGES files from their motor sport customers drove Rimor to look for a replacement CAM system.
"We found that the representation and importing of IGES files was very good in DEPOCAM," said Ray Oakley, Sales Manager, Rimor Ltd.
Rimor have an impressive plant list including 8 Bridgeport machining centres, 1 Mazak machining centre, an Acramatic Eagle, driven tooling lathes, 2 Tos machining centres and a Sachman 5 axis machining centre. These machines have a range of control systems and some also have 4th axis units, so good quality postprocessors were important for productivity. With DEPOCAM it was easy to tailor them to suit the differences between each control.
Rimor also wanted to use high speed techniques on their conventional machine tools within the limits of the feeds and speeds available on each machine. A combination of improvements to the postprocessed code and smoother toolpaths generated by DEPOCAM, made it possible to run at much higher feedrates without the jerky movement of the machine, which had previously been experienced by Rimor.
Smoothing algorithms inside DEPOCAM ensure that there are no sudden direction changes in the NC code, so that the machine tool does not need to accelerate or decelerate unnecessarily, while even stepovers and smooth corner transitions ensure that the tool load is constant.
Motor sport applications for Rimor include engine build components such as cam covers and fuel line components. These are mainly aluminium and are machined from a solid block. Typical features include complex pockets and webs to produce a very light yet structurally sound component.
For performance gearboxes they produce selector forks, transmission shafts and gear blanks, which require milling operations to cut lightening holes, as well as turning operations. Titanium suspension components are tougher to machine, requiring careful selection of tooling, feeds and speeds and cutting techniques.
"Titanium is a difficult material to cut," says Ray Oakley, "we machine from a solid block supplied by the customer, and in some cases it is necessary to cut deep pockets with small tools. We find that the correct tooling geometry makes a lot of difference on Titanium,” continued Ray Oakley.
Rimor use the area clearance, waterline, raster and constant stepover routines in DEPOCAM for Titanium and get improved cutter life by machining the walls first and adjusting the angles which are to be cut, to avoid hitting the side of the job.
For deep pockets in Titanium, Rimor use a sequence, starting off with large tooling and progressively working down to depth with smaller and longer tools. The ability to reliably avoid ploughing into unmachined material and to take very small cuts is vital for tool life and finish. Furthermore, with customer supplied material, very short production runs and lengthy cycle times, errors in machining can be very costly.
"We frequently cut pockets which are 60mm deep and we use tools down to 2mm diameter. Combining the machining routines available in DEPOCAM produces a very smooth surface finish at the transition between the different tools we are using," said Ray Oakley.
Rimor have a night shift, and are able to run 24 hours per day seven days per week, with certain machines running unmanned at weekends and evenings. This cannot be done without reliable toolpaths. The shorter lead times and reduced cycle times achieved with DEPOCAM have increased efficiency and the enhanced IGES capabilities have simplified the importing of CAD data from customers.
"NC Graphics DEPOCAM made some significant savings in machining time," said Ray Oakley, "on one job we reduced the cycle time by 47%. The Windows interface also made the system very easy to use and understand."
Rimor chose DEPOCAM with the aim of increasing productivity for their motor sport customers, the results have proved that they made the right choice.
For more information:
NC Graphics (Cambridge) Ltd, Silverwood Lodge, Ely Road,
Waterbeach, Cambridge, CB5 9NN, United Kingdom
Tel: +44 (0) 1223 861539
Fax: +44 (0) 1223 440249
Contact: Mrs Estelle Dunsmuir, Marketing Manager