Friday, August 18, 2006

Promoting 'best practice' in mould making

The ANDIAMO partnership between Sescoi, Erowa, Zwicker Systems, and Cimatech was created to promote best practice, state of the art automation within the mold and tool making industry.
Cimatech, a moldmaker based near Salzburg in Austria, has embraced the ANDIAMO concept, using it in its day-to-day manufacture to achieve a 50% increase in productivity and a 70% reduction in through put time, all in a paperless production environment. The aim of ANDIAMO, to create a fully automated mold and die shop which integrates the physical technical world with planning and management, has been achieved at Cimatech, where the company, which specialises in the manufacturing of electrodes, produces up to 12,000 electrodes per production cell each year. The four partner companies worked closely together to make the concept a reality.

Real time data is fed back into WorkPLAN job management system via microchips fitted to each component by the technical automation solution JMSPro from Zwicker systems and Erowa.

Detailed and live information of progress in the workshop allows managers to respond quickly to the changing situation, coordinating job and time management, manufacturing monitoring, scheduling, planning, CAD/CAM integration, manual and CNC manufacturing, inspection, and part identification into a homogeneous process.

The ANDIAMO partnership is inviting toolmaking companies to their 'eye-opening' seminars at Cimatech's Salzburg site so that they can experience the ANDIAMO concept, at first hand and 'hands-on', building a part of a simple tool themselves from scratch in one and a half days.

Additionally, the ANDIAMO partnership can carry out appraisal and technology transfer for toolmaking companies to establish the most suitable combination of equipment and software necessary to automate their complete tool manufacturing processes.

ANDIAMO also shows how mold makers should integrate their own customers and suppliers to benefit from an as yet unknown supply-chain-management concept for the tooling industry.

Closing the loop in tool manufacture at Cimatech shows how automation and control can produce some spectacular results, accurately managing an inherently complex set of events.

Cimatech are running at full capacity and are benefiting from very worthwhile cost savings and productivity improvements, helping them to stay way ahead of their competitors.

More laser power expands tooling repair scope

Delivering a peak power of 10kW, a tooling repair laser system is capable of melting wire onto the tool to build up damaged areas, with minimal HAZ, restoring the tool to its original condition.
Rofin has again pushed the boundaries of tool repair by introducing a new higher power laser to their range. The StarWeld Tool Integral is a laser welder with three heavy-duty axes designed to manipulate tools weighing up to 350kg. The laser is capable of melting wire onto the tool to build up damaged areas restoring the tool to its original condition.

The laser has many advantages over other welding methods such as TIG.

The laser beam minimises post processing due to the very fine welds that can be achieved using wires as small as 100 microns.

The laser is also very focused which means that minimal heat can be used, reducing heat affected zones.

The new higher peak power takes the laser from 6kW to 10kW, that is more than a 60% increase! Copper and aluminium have historically been difficult to weld due to their high reflectivity and conductivity.

This additional power makes these types of materials much easier to repair.

The laser also benefits from swiveling optics allowing the laser beam to be directed in to normally difficult to access areas of the tool.

Monday, August 14, 2006

Ejector system successfully frees moulded balls

Overcoming a problem with moulding small plastics balls, the smallest Tulip Ejector in the range was able to design a mould that allowed the plastics balls to be ejected successfully.
As well as being the UK's largest manufacturer of precision engineered standard components for use in injection moulding and die-casting tools, DMS-Diemould also exclusively distributes standard parts for a number of 'partner' companies, such as Barcelona-based Cumsa. The benefits of this arrangement were recently enjoyed by Ron Copleston Designs, a company run by semi-retired former Philips design engineer, Ron Copleston. A high profile London-based university recently approached RCD with an idea for a product, tasking the company with developing a viable method of manufacture.

While the intended application and specific design of the product are still under wraps, it can be described as containing a series of ball and socket joints assembled on a special lattice that allows the joints to bend up to 15 deg in any direction.

The balls are manufactured from a selection of thermoplastics materials (a critical factor in the design and application of the product) ranging up to tough polycarbonate.

The diameter of the balls measures just a few millimeters.

The difficulty for RCD was that the balls were not allowed to exhibit any material flow lines or seams and so could not be produced in a traditional two-half ball mould.

'The first thought I had was 'how on earth are we going to mould these balls?',' said Ron Copleston.

'Fortunately I have a relationship with DMS-Diemould stretching back over 25 years.

When I approached them with the problem they suggested I try Tulip Ejector from Cumsa, a product they distribute in the UK.' The close pitch also presented a difficulty, however, using the smallest Tulip Ejector in the range - the EE060175 - RCD was able to design a mould that allowed the plastics balls to be ejected successfully.

RCD's mouldmaker, Aylesbury-based Uniform Tooling, subsequently purchased three Tulip Ejectors from DMS-Diemould along with the associated die blocks, plates, pillars and bushes required to manufacture the necessary amount of moulds, each of which measured approximately 100mm square.

'The whole design of the mould revolves around the Tulip Ejectors,' explainedCopleston.

'They are probably best described as collet-type devices that spring open so that products with undercuts can be ejected without any difficulty.

They proved to be the perfect solution for this project.' Cumsa has been established in Spain for over 30 years and has evolved into a respected manufacturer of standard mechanisms for moulds.

Their patented designs permit the release of parts featuring small undercuts with minimal mechanical movement and a minimum footprint in the tool.

The Tulip Ejector is height adjustable and easy to install.

It is hardened to 45HRc and coated in Balinit C for low friction release action.

There are 12 models of Tulip Ejector available through DMS-Diemould, ranging from 6mm in diameter and 175mm in length, up to 12mm in diameter and 325mm in length.

Trends in mould and die making reviewed

Surviving European mould makers are investing in CAD/CAM and unmanned machining to reduce labour costs, shorten delivery times and meet overseas competition, writes Mike Page.
The European Association of machine tool manufacturers - CECIMO - under its MANTYS (MANufacturing TechnologYS) initiatives, commissioned a review of current trends and future developments in the mould and die manufacturing sector. The objectives were to review the state-of-the-art manufacturing methods and procedures and identify current best practice in the mould and die-manufacturing sector with particular emphasis on the following - * Design and production processes (CAD/CAM, rapid prototyping, HSC, HSM versus diesinking EDM) which increase competitiveness and reduce time to market. * Identification of those product sectors which are to be seen as most likely making significant changes from traditional plastics and metals components over to greater use of plastics and/or metals mouldings.

* Identification of those product sectors likely to make greater use of metals mouldings following ongoing developments in diecasting, thixo-moulding, etc.

* Identification of mould and diemaker attitudes (particularly SMEs) in terms of whether current CAD/CAM systems are fast enough, flexible enough and affordable enough to adopt.

Also, whether demand will grow for rapid prototyping systems.

* Identification of new technologies either currently available or under development which are likely to be demanded by major end user sectors.

* Identification, with possible future timescales, for growth in use of larger diesets and micro- and nano-diesets, and establish whether existing machining systems can cope or whether new technology developments will be required.

Interviews - the process of trying to gain interviews with mould and die makers in Europe got off to a very slow start, some reluctance being expressed by those firms contacted.

Eventually, ICEP (Portuguese Trade organisation) invited me to join a small group to tour seven mould and die makers in Portugal.

The Portuguese are the largest, if not, second largest mould producers in the EU.

I was also able to interview TN, Italy a small mould and die maker present at the Bi-Mu exhibition in Milano (October 5).

Visits were made to the UK's GTMA (Gauge and Tool Makers' Association) in Princess Risborough, and to the University of Cambridge's Faculty of Engineering Library, to carry out literature searches.

Contact had also been made with the University of Bremen, Germany, concerning their research into micro-machining in association with the University of Aachen and the Oklahoma State University, USA.

A literary research was carried out on the 'Manufacturingtalk' Web site for the last two years, to provide an idea of what mould and die companies are currently buying.

Most of the companies are in the UK, with a few in Germany and Switzerland.

UCIMU per Produrre - the Italian Association for machine tool builders and Production - circulated a questionaire among nine Italian mould and die makers.

* Design and production processes (CAD/CAM, rapid prototyping, HSC, HDM versus diesinking EDM), which increase competitiveness and reduce time to market - of the mould and die companies visited; only three of the larger companies had established any kind of rapid prototyping facility.

The smaller companies subcontracted out prototyping and modelling.

All companies visited expressed the intention of adding on a fast prototyping facility as the growing trend is for customers to involve the mould and die-maker at the 'concept' stage of product development.

Rapid prototyping processes seen in use (Simoldes and SET - Ibermoldes and Moliporex) were using stereolithography, selective laser sintering and silicone moulding.

Most companies in Italy, Portugal and the UK used their high speed milling (HSM) machining centres to produce CAD models in resins or aluminium.

* Rapid prototyping and 'rapid tool making' processes - stereolithography (SLA) - producing models and limited function prototypes.

Selective laser sintering - producing models and functional prototypes in plastics, resins and metals - including steels.

The process is also used by some foundries for producing patterns for foundry work, such as investment casting.

Also prototype and limited production moulds have been produced.

Surface metal deposition (SMD) - use of robotic welding processes such as TIG or MIG, to progressively build a usable prototype shape.

For example, Trumpf, Germany, offers an inert gas purged system for TIG welding prototype structures out of non-ferrous metals and alloys.

Could be considered for fabricating small moulds.

University of Cranfield, UK, has done extensive work using robotic TIG and MIG welding.

In co-operation with Rolls Royce, the latter has fabricated a usable 'centre section' for a Trent jet engine using robotic TIG deposited weld metal.

SMD could be considered for producing small mould 'pre-forms' to be machined to net shape.

Selective laser melting (SLM) - similar to selective laser sintering, except that a full fusion of powders is done to achieve a dense 'as cast' component.- including alloying.

Main work on this is in Germany and the UK.

Laser tool repair systems - generally a solid state laser is used in direct laser forming - producing replacement parts in a metal powder bed as with selective laser sintering.

Also direct powder deposition - where metal powder spray is introduced at point of laser beam contact on a tool surface to build up a layer of new metal in a small area.

Silicone moulding - models produced by SLA are used as patterns.

The patterns are coated with silicone materials, allowed to set, then split, pattern removed, then plastics material is poured into the silicone mould.

High speed milling (HSM) - widely used to produce models and prototypes in non-ferrous light metals, plastics and resins.

Many mould makers use HSM to produce short run or 'prototype' moulds.

SET for example, produces 'hybrid', short-run moulds combining an aluminium structure with other materials such as copper (heat sink properties) and die steel inserts.

Prototype or production moulds - rapid production of relatively complex moulds in aluminium alloys - for example, from trade and technical literature, Sierra Chase, a mould maker located in Richmond, Illinois, USA, actively uses aluminium alloy moulds for runs of up to 500,000 parts.

An aluminium mould can be produced in as little as three days.

The more complex moulds in 4-6 weeks (that is a mould having moving die sections, retractable features, etc.).

Sierra uses 'Fortal' aluminium alloy from France.

Also Toolcraft, UK, uses coating systems to improve the life of machined aluminium moulds.

Milling versus EDM - Without any exception, all companies visited - and read about in available technical and trade press literature - were using conventional rough CNC milling - and sometimes an intermediate roughing stage - and finished off with high speed machining (HSM).

Their goal was not necessarily that of achieving a faster machining cycle - though it was a common result - but to eliminate, as much as possible the hand finishing and polishing of mould surfaces.

For example, from Trade literature, CAC Tooling in High Wycombe, UK, said it only took 18 days from receipt of CAD data to produce a four-cavity mould (automotive parts) that involved 16 separate in-die movements during the moulding cycle.

The company commented that HSM generated the big time saving - not from a machining cycle point of view - but a drastic reduction in hand polishing of mould surfaces.

The use of HSM and milling cutters, such as ball nose cutters of 1mm diameter, has enabled Haverhill Mould and Tooling, UK, to almost completely eliminate EDM for the machining of sharp corners.

HSM has also drastically reduced manual polishing time.

During the visits to the seven Portuguese mould makers, analysing the results of the UCIMU survey and the literature searches and in the interview with TN, most companies had relegated die-sinking EDM to detail finishing.

In some cases the larger companies would use EDM for producing customer-defined surface textures.

Many companies would sub-contract out such work.

The detail EDM work involves automatic toolchanger (ATC) or fast manual change systems for electrodes.

Only one mould maker was seen to be using automatic loading of palletised workpieces (small moulds) to an EDM.

A few examples are also among the literature searches.

All companies made use of wire edm systems for the initial profiling of plates or billets for detail mould parts.

All companies would welcome the development of milling cutters capable of doubling or trebling existing rough milling metal removal rates.

Only one company was seen using 'high speed roughing' of 55-65HRC pre-hardened diesteels with tooling developed by Hitachi.

One Italian company also reports using HSM for roughing as well as finishing.

Developments in 'micrograin' carbides with 'nanocomposite' coatings are seen as a route towards effective high speed roughing in pre-hardened diesteels 45-65 HRC.

There was no real interest expressed by any Italian, German, Swiss, Portuguese or UK companies surveyed in the 'mixing' of say, HSM and EDM in one machine.

I understand that Parpas, Italy, delivered such a machining system some four years ago to a Belgian tyre moulds maker.

EDM is used for detail finishing and filigree work on the large tyre moulds.

One heard that the customer is currently using the combined milling/EDM system in prototype mould work.

In trade and technical literature, mould makers expressed interest in Fanuc's 'ultra fine wire' EDM (using 0.05mm diameter brass wire) for producing fine detail work.

Many mould makers, for example, also provide clipping, trimming and crimping tooling for trimming plastics components after moulding.

The ultra-fine wire-EDM allows them to produce even finer tooling for, say medical parts, small electronics encapsulation, etc.

ECM (electro-chemical machining) is not much discussed these days, but Impulse ECM, based in Gloucestershire, UK, claims it has increased metal removal rates by a factor of 100, when compared with EDM.

ECM metal removal rates in diesteels can reach 1000mm3/min.

The company has effectively reduced electrode: machined surface gap to 20 microns, compared, typically, with 0.25mm for EDM.

A much more accurate profile is therefore possible, says the company, while surface finishes generated are 0.1-0.03 micron Ra.

Also the company claims increased graphite electrode life - giving an example of 50 cavities produced by one graphite electrode.

(Note that in consultation with EDM machine suppliers, they agreed that in conventional diesinking plunge roughing modes, 0.20-0.25mm 'spark gap' (that is electrode 'undersize' with reference to finished die cavity dimension) was typical.

Much depends on the material and whether the EDM machine is operating in rough, semi-rough, finish, or polish modes.

In 'polish mode', spark gap - or, let us say EDM electrode 'undersize' dimension could be 20 microns or smaller).

Multi-tasking machine tool systems - An interesting development at AE Formen und Werkzeugbau, Germany, is the combination of automated high speed milling, jig grinding and co-ordinate measuring in a Roeders machining centre.

The user says it can now perform around three-quarters of machining on a typical high pressure die-casting tool in 'one hit'.

The software for jig grinding in the machining centre's CNC 'mimics' the manually-operated jig grinding process (alternatively grinding/sensing/regrinding the bores until the desired result is achieved).

Also the measuring software can assess and correct for distortion in the post-hardened workpiece before machining commences.

The whole HSM/jig grind/CMM process can be performed unmanned.

* Identification of those product sectors which are to be seen as most likely making significant changes from traditional plastics and metals components over to greater use of plastics and/or metals mouldings.

Automotive - with the ongoing developments in stiffer structural plastics and the growing use of 'multi-component' (components with mixed plastics materials), plastics content in cars will increase.

For example, at the 'Moulds Event' 2004, Portugal (organised by INVEMA and AFM, October 10-15, 2004), it was reported that plastics content in VW models in 1990 was around 18%.

It has since risen to 25% (including SMC and composites) for 2004 models.

VW sees, for the 'near' future (say next 5 years) plastics content rising to 34% plastics - the main 'driver' is weight saving.

The attractions of SMC in 'niche' car production include less design time, shorter prototyping times and reduced tool design and manufacturing time.

Elements seen as going over to plastics include (or SMC) include more panel work such as doors, trunk lids and bonnet lids, inner wheel arches and front and rear wings.

For example, BP plastics reinforced with 'long' fibres are being used for door panels and front and rear panels in the Citroen C3 passenger car, said Simoldes Acos.

More metal items in the 'hot' parts of IC engines such as cylinder head covers and sumps are being replaced by plastics items.

For example, Moldit, Portugal referred to producing sumps from composite plastics to replace aluminium pressings or diecastings.

A number of companies are using plastics fuel tanks - usually blow-moulded poltrusions.

Also, plastics road wheels are under development - albeit mostly for 'niche' cars.

A startling development, noted by Moldit, is its involvement in a project to produce camping 'gas bottles by a moulding process that moulds an internal plastics lining inside a fibre-reinforced structure.

The 'driver' for this development is rising world steel prices.

Moliporex opined that in some sectors costs are undulating between aluminium and plastics - the company referred to automobile wheels.

Equally, said the company, in aerospace, Boeing for example has been replacing some composites parts with moulded thermoplastics.

Moldoplastico noted that new markets are focussing on filled polypropylenes rather than 'engineering' plastics.

The company quoted the example of platen-type pallets moulded, with the aid of gas-injection to produce strong structures - in filled polypropylene.

As far as garden furniture and other furniture were concerned, Moldoplastico was doing more work in overmoulding plastics onto aluminium structures.

Yet in some domestic appliance sectors where overmoulding had been common (plastics onto aluminium), the development of multi-plastics component moulds had led to the replacement of over-moulded structures with two-part all-plastics structures.

The aerospace sector is increasing its use of plastics and composites.

For example, the Airbus A380 aircraft has 22% of its structural weight comprising composites.

Boeing, on its next project, is looking for 50%.

Composites structure fabrication includes poltrusion, braiding, placing fibres, automatic tape lay-up and so on.

A large growth sector is seen in medical and electronics equipment, where the development of micro-machining and micro moulding techniques facilitates replacing metals components with plastics ones.

There could also be a new growth sector in using SLA and selective laser sintering or melting as batch-production tools for plastics parts.

* Identification of those product sectors likely to make greater use of metals mouldings following ongoing developments in diecasting, thixo-moulding, etc.

This is a difficult one, as the main 'driver' is materials price.

Thixomoulding of non-ferrous alloy enclosures is a rapidly growing area for industrial and domestic 'consumer' electronics devices such as mobile phones, in-the-hand portable PCs, gaming devices and mass-produced enclosures.

Thixomoulding provides OEMs with a new decorative medium and, a more robust enclosure when compared with simple plastics enclosures.

Diecasting is constantly under threat from plastics moulding - and it works the other way too.

As far as the mould and die industry concerned - it is another mould or mould change, depending whether an individual plastics mould maker has diecasting mould experience or not - and vice-versa.

There is some growth in steels/steel alloy diecasting - mostly stainless steels for leisure industry components (for example, yacht fittings).

* Identification of mould and diemaker attitudes (particularly SMEs) in terms of whether current CAD/CAM systems are fast enough, flexible enough and affordable enough to adopt.

Also, whether demand will grow for fast prototyping systems.

All companies visited had acquired HSM during the last five years.

No company visited was yet using continuous path 5-axis milling.

All the Portuguese and Italian companies contacted were 'considering' continuous path (CP) five-axis where it was relevant to the types of moulds being produced.

Reservations were expressed about not just the cost of acquiring the CP 5-axis machining facility - be it CNC miller or machining centre - but the software for translation of CAD files into new cam systems and the CAM systems themselves.

Also some of the Italian companies expressed concern over the 'learning curve' for the introduction of simultaneous 4- and 5-axis machining.

They felt too, that some form of networking was preferable to deal with the larger NC files.

The complaint from mould and die SMEs was that they were largely left to themselves to interface such networks with the variety of CNCs being used.

Unless SMEs had experienced computer networking knowledge, expensive consultants had to be recruited.

Some companies - in Portugal and Italy - expressed reservations about the accuracy of individual machine tools' dynamic interpretation of CP 3-axis NC programs for HSM.

Preferences were expressed in terms of individual CNC machine tool suppliers' products showing a capability of faithfully reproducing complex contoured surfaces and pockets from CP 3-axis programs - let alone CP 5-axis! Two companies were using 3+2 'five-axis' machining, sometimes with similar problems.

There could be a problem too, when retrofitting HSM heads to existing CNC 3-axis millers that the changed dynamics could produce replication errors.

As to speed of current CAD/CAM systems, this did not appear to be a big problem - software can always get faster.

The main concern was that of achieving 'seamless' CAD/CAM.

A truly 'seamless' CAD/CAM would eliminate constant checking and re-checking of files and programs at each stage of translation of a CAD file into NC cutting paths.

This opinion was expressed by Italian and Portuguese mould makers.

As an aside, Data Mouldings in the UK reports successful use of a HSM machining centre and NC Graphics' DepoCAM software for HSM of mould pocket features.

All seven Portuguese companies visited and some UK companies were using 3D solid modelling software and also made extensive use of 'touch probe' digitising systems (one company had a laser scanning system) - either for digitising models, digitising critical tool surface areas during machining or digitising tooling sent in for repair or modifications.

All companies involved in the automotive sector have to cope with extensive requests for modifications to moulds during and after their manufacture.

All companies would consider acquiring laser-scanning systems - when the price was seen as 'right'.

As for true 'paperless' or 'model-free' CAD/CAM there are one or two cases where there had been enough confidence in visualisation techniques to move straight into mould manufacture without producing 'models'.

An example of 'model-less' die production, taken from literature search - is Plasticos Castella, Spain, that wished to reduce the mould and die design cycle by having mould design more tightly integrated with part design.

Unigraphics NX intergrated with NX Mold Wizard was applied to produce core and cavity surfaces directly from the part shape file, while 'common' parts were pulled from the company's 3D component library.

Another example is that of the VX Corp, USA, which claims to have 'seamlessly' closed what it sees as the CAD-CAM 'gap' with software that generates NC programs from CAD file data.

In general, adding on simulation and visualisation software to the CAD/CAM activities is seen as very expensive - say EUR 60,000/seat.

In the automotive industry, some Tier 1s are assisting mould suppliers to acquire the software - even offering cash, if not extensive support in 'tuning' systems to improve accuracy of data input.

It is generally felt that mould makers who do not acquire the software will eventually go out of business.

Of all the companies interviewed - and who had responded to the UCIMU survey - who were not yet operating rapid prototyping systems (other than using HSM) indicated that they are considering acquiring some form of rapid prototyping system (stereolithography or selective laser sintering) in 'the near future'.

The 'driver' is the customer wishing its mould supplier to become involved at the product 'concept' stage.

* Identification of new technologies either currently available or under development which are likely to be demanded by major end user sectors.

Rapid prototyping and rapid tool making systems have already been discussed above.

In the Trade and Technical literature, a 'waggish' headline asked: 'Are injection mouldings' days numbered?' The reason for this question was the growing use of so-called 'rapid manufacturing', which is seen as making inroads into low volume moulding areas.

Terry Wohlers - president of Wohlers Associates, Fort Collins, Colorado, USA - said that OEMs are looking at making 'final-end-use' parts in small batches for: * Medical and aerospace.

* Automotive and aircraft interior fittings.

* Consumer goods.

For example, Align Technology (orthodontic products), based in Santa Clara, California, USA, has installed 10 SLA machines from 3D Systems to mass-produce 'Invisalign' clear plastics dental braces.

The SLAs produce patterns used in a plastics casting process.

Consequently, hearing aid manufacturers are evaluating SLA and final deposition modelling for fabricating 'custom-fit' hearing aids.

Data from a laser scan of a silicone ear impression are used to generate design and manufacturing data for SLA production.

Wohlers also sees potential for SLA batch production in sportsgear (helmets, shoulder pads and masks).

Also Bell Helicopter is using SLA investment-casting cycle to produce 'flight-ready' parts.

In general, SLA, selective laser sintering, selective laser melting and surface metal deposition (robotic TIG and MIG) are seen as future candidates for small batch or 'few-off' production.

It has been suggested, for example, that robotic TIG or MIG could produce mould preforms to minimise the amount of metal removal and would only require HSM/EDM to finish off.

Comment - SLA and selective laser sintering and melting machines are designed for 'one-off' prototyping.

There is a growing market for 'rapid manufacturing' machines that could be pallet- or robot-served to satisfy the need for 'rapid manufacturing' production systems - ideally for unmanned operation.

Micro-moulding - that micro-moulding is regarded now as a dynamic growth industry is illustrated by the number of patents taken out each year for micromilling toolsteels.

In 1990 the number of patents registered were: * USA - 60.

* Japan - 60.

* Germany - 30.

In 1999: * USA - 170.

* Japan - 70.

* Germany - 70.

These figures reflect an increasing interest in the machining of wear-resistant micro-moulds - and the machining processes demand complete process control.

The Fraunhofer Institute of production technology (IPT) in Germany is currently running a research project: 'Use of Micromilling for the Production of Injection Moulding'.

The project report sees milling as superior to grinding, EDM and laser machining.

The project is basically divided into two areas: Ultra Precision (UP) - for large components requiring much detail machined to sub-micron accuracy (such as moulds for lighting system reflectors - see below).

Microcutting - for machining structures under 100 micron in dimension.

For UP machining, monocrystalline diamond (MCD) provides the 'atomic level sharpness' cutting edges.

Also micrograin carbide cutters are used for machining micro non-optical surfaces and also copper electrodes for micro-EDM.

Applications include filigree jewellery and watch parts.

In a joint project, the University of Cranfield, UK, and Loadpoint, Sweden, is developing a high metal removal rate, creep-feed grinding process.

It is based on a concept from the UK's National Physical Laboratory - to produce optical quality finishes on silicon, glass, ceramics and tool steels without the need for lapping or polishing.

The process produces 2D and 3D forms to surface finishes of 1- 20nm Ra.

Also in micro machining and UP machining, the Laboratory for Precision Machinery (LFM) at the University of Bremen, Germany, has a project: 'Development of Ultra-precise Milling Techniques for the Manufacture of Optical Quality Moulds with Continuous and Microstructural Surfaces'.

Project leaders are E Brinksmeier and L Autschbach.

The LFM project has developed diamond fly-cutting to produce pyramidal structures.

Also ball-end milling cutters and 'half-arc' monocrystalline diamond tooling has been used to generate micro-free-form surfaces and continuous free-form shapes under 100 micron in different materials.

Brinksmeier and Autschbach are also investigating contour boring and raster-milling of moulds for an ultra-precision open ring light system for medical applications using half-arc monocrystalline diamond tooling.

Raster milling is used for producing microstructures of spherical surfaces, typically 3.8 micron deep x 13 micron x 9.8 micron to a surface finish of 11nm Ra.

Brinksmeier and W.Preusse - also from LFM - have also done work on maintaining permanent feedback between mould machining and replication.

Another project is the diamond turning of moulds for producing precision aspherical lenses.

The University of Bremen, the Technical University of Aachen - both in Germany - and the Oklahoma State University, USA, are involved in a project 'Process Chains for the Replication of Complex Optical Elements' (SFB/TR4) and have proposed the setting up of a Co-operative research centre.

Focus of research is investigating the processing of moulds with complex surfaces for producing lens arrays, Fresnel lenses or symmetrical surfaces - and combinations of these.

Uses are operation theatre lighting and automotive lighting.

The project goal is to achieve automated production with full process control.

Comment - apart from a handful of machine tool builders - micromachining systems are still largely laboratory tools in concept, and are not necessarily 'production environmentally friendly'.

Also, the Manufacturing Engineering Centre (MEC) at Cardiff, Wales, in its work on micro-tooling pointed out the difficulties of measuring micro-machined surface roughness.

Current working smoothness for micro-machined surfaces is usually less than 0.1 micron Ra.

The MEC says Ra is not entirely satisfactory at this scale, as it represents an average figure.

The MEC believes measuring smoothness in Rz or Ty may prove to be more satisfactory.

* Identification, with possible future timescales, for growth in use of larger diesets and micro- and nano-diesets, and establish whether existing machining systems can cope or whether new technology developments will be required.

Larger diesets - although composites structures are being increasingly used in 'niche' cars for panels, the fact that more use is being made of filled polypropylenes for panel structures in production cars, the demand for more large diesets will increase.

The fact that multi-component/multi-colour diesets are very complex could mean a growing demand for large, but precise CP 3-5 axis CNC milling machines.

It is interesting to note that, for example, German machine tool builder, F Zimmermann, is using a precision rack and pinion drive in its latest gantry-type CNC high speed milling machine.

The company claims higher positioning and repeatability accuracies when compared with ballscrew and linear motor systems, owing to the rack and pinion system's 'very high dynamic rigidity'.

Micro- and nano-diesets - identified as a future growth industry, but there are only a handful of machine tool builders producing machine tools anywhere near capable of using 3-5-axis movements to replicate accurately complex surfaces on microstructures.

There is also the question of the availability of commercial systems for rapidly measuring such surfaces under production conditions (see comment in Micro moulding above).

That tooling systems are being developed indicates that tooling technology could be ahead of machine tool technology in this area.

SLA and selective laser sintering or melting systems - could be a new growth sector in production ('rapid manufacturing') as well as on-going take-up for rapid prototyping.

Current systems are structured more to 'prototyping' scenarios; perhaps builders need to reconsider machine designs for batch production work - for example, interfacing with automatic pallet or part handling systems.

High speed rough milling - mould and die makers eagerly await milling cutters capable of doubling or trebling 'conventional' rough-milling metal removal rates.

5-axis continuous path milling - that machine tools faithfully replicate the NC programs, particularly on cornering and producing complex profiles.

Automation systems - with reference to the UK's Gauge and Toolmakers' Association's 'Fastool' project, which, for example, is developing a monorail-based pallet handling system (Fatronik, Spain) for transferring work from HSM to VMC to EDM.

'Seamless' CAD/CAM - to eliminate time lost in checking/rechecking translations of CAD files into CAM and NC programs.

There is the Emould@work project by the UK's GTMA and Delcam, which is currently investigating the problem and is looking at 'Wizards' to automate key mould design and manufacturing processes and develop a portal with powerful supplier sourcing and project management tools.

* Markets - there are many rumours circulating about the future of mould and die making in the Western EU.

Germany and Portugal represent the largest concentrations of mould and die makers.

Essentially, the fear is: * OEMs are sourcing 'cheap' moulds and dies in E Europe, S E Asia and China.

* OEMs are transferring moulding capacity to E Europe, S E Asia and China and that mould making will follow.

In reality, it is the 'conventional' or 'simple' mould-making work that is being increasingly sourced in those countries.

Complex mould making is staying mostly with Western suppliers.

OEMs are generally not moving their technical centres and research and development centres out of Western Europe.

But advise that mould makers have to work closer with their technical R and D if they wish to stay in business.

It means that mould makers have to work closer with the Tier 1 or OEM at the product 'concept' stage.

They will be asked to do prototyping, prototype tooling, pre-production and offer extensive 'post mould supply' work in the form of technical support.