Local CNC programming facilities and Ethernet communications with machine tools helps a mould maker to complete in 6 hours machining which previously would have taken 15 hours.

Local CNC programming facilities and Ethernet communications with machine tools helps a mould maker to complete in 6 hours machining which previously would have taken 15 hours. Modern Moulds and Tools, based in Lancing, West Sussex, UK, has been making tools for over twenty years. It has a ten-year relationship with NC Graphics, with four seats of DEPOCAM and four of toolmaker connected through wireless networking.

This allows mobile workstations on the shop floor, which provide local CNC programming facilities and Ethernet communications with its machine tools.

The initial choice of ToolMaker and DEPOCAM was due to its compatibility with other systems, enabling solid models to be reliably imported, while ToolMaker additionally enables the repair and manipulation of surface data, which can be difficult to achieve in solid modelling systems.

John Horspool, Works Director for Modern Moulds, has been working with CAD/CAM systems since 1987 so he is well aware of the technical implications of re-engineering customer's design data to generate the necessary electrodes and toolpaths to produce a completed mould tool.

He realised that conventional machine tools and tooling were not capable of economically producing the complex shapes required in the latest plastics components.

'We chose to implement a complete package of DEPOCAM, DEPO-FHT tooling and a Bridgeport machining centre to meet our requirements for high speed machining.

Now we rough out core and cavity details to within 0.2mm, before vacuum hardening.

Next we grind to fit into the mould base, and then in the hardened state, semi-finish and finish using high speed machining techniques.' Modern Moulds is now able to complete in 6 hours machining which previously would have taken 15 hours.

'DEPOCAM allows us to rough out true to the form being generated, and introduce surfaces to trim toolpaths.

These features keep the tool in the material for the maximum possible time.

In addition the DEPO-FHT indexable button cutters and Tornado cutters enable us to cut up to 62 Rockwell,' continued Horspool.

Its confidence in DEPOCAM and ToolMaker has enabled Modern Moulds to introduce the concept of synchronised manufacture.

For it to succeed it requires absolute confidence in the reliability of the toolpaths, a multi-skilled workforce, and individual responsibility for quality, combined with modular fixturing.

Horspool explains, 'We design the tool around the customers component, applying shrinkage and developing moving parts.

The cavity machining is prepared, and where electrodes are required, they are created on System 3R holders.

Inside DEPOCAM the electrodes are positioned at a common datum and the cutter path is programmed around that.' With sixteen skilled toolmakers, and the ease of use of DEPOCAM, each machinist is able to program his own electrodes, and because the fixturing is common to machining centres, lathes and die sinkers, individual tool setting is eliminated.

The set-up sheet provides all the information required for each electrode, the X and Y position relative to the common datum, together with lift or drop for height, which is kept to a round number for simplicity.

With this method of manufacture every job is the same, in that the sparking operation ends at Z zero, removing the need to specify a depth to spark to, the associated possibility of error, and multiple setting operations.

'Centring the spark eroder off an edge for each electrode used to take a considerable time, especially when fifty electrodes were required in one tool.

The new methods we have introduced with DEPOCAM make it only necessary to do this once,' said Horspool.

The accuracy now possible through the use of DEPOCAM and high speed machining techniques has encouraged Modern Moulds to split complex electrodes into smaller and simpler elements.

'We know that the individual electrodes will produce a perfect result when used together on the cavity, the quantity per job can vary between five and seventy five depending on its complexity,' said Horspool.

The benefit for the company is that individual electrodes are easier to manufacture, and should an error occur, the cost in time and materials of remaking a simple one is much reduced.

For maximum efficiency Modern Moulds needed to introduce flexibility in its highly skilled workforce.

Systems which were simple to use and reliable were essential for mobility between tasks.

Introducing structured working methods, the use of a common datum, the short learning curve for DEPOCAM and the power of ToolMaker were major factors in the successful implementation of synchronised manufacture.

Additionally, each toolmaker checks his own work, inspecting and signing off his completed operations, making the whole team communally responsible for the finished tool, ensuring high quality is built into the manufacturing process and that it is a core principle for the company.