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News Release from: Renishaw | Subject: Cyclone Scanning System
Edited by the Engineeringtalk Editorial Team on 01 June 2000

Renishaw's Cyclone gives Doll Makers a
head start

Doll making in Ireland is a traditional craft and has recently found the benefits of scanning technology.

TIRAC, the Toolmaking Industry Research and Advisory Centre, set up in 1993, has developed and expanded its services to meet the continuous growth and demand for expertise in the toolmaking, mould making, die making and advanced manufacturing industries both in Ireland and abroad The Centre is recognised as being at the leading edge of CAD/CAM technology, providing a new insight for toolmaking and manufacturing industries in the development of their own systems and actively helping them overcome capacity, manufacturing and technological problems

Situated within, and wholly owned by, the Institute of Technology Sligo, TIRAC has access to the most modern technology available which includes Renishaw's Cyclone Scanning System.

Ger Reilly, Manager of the Centre, explained the manufacturing operation within TIRAC.

'We are closely associated with the Irish Mould Making Corporation and by relation specialise in tool and mould machining and electrode manufacture.

In the past the CAD files would have to be generated from paper drawings but more and more toolmakers are getting to the stage where they themselves can provide a 3D CAD model.

We still receive paper drawings and have to create the 3D model in DUCT or Pro Engineer and generate the code.

Once generated we DNC-link it directly to the machines to produce the electrodes which include two Deckel Maho MH 600E's and one Deckel Maho MH 700S 5-axis universal milling and drilling centres.' 'We wanted to utilise the Deckel's for machining operations and had been carrying out a lot of point- to-point digitising on the Zeiss CMM, using the machines bespoke digitising software.

A client would present us with an unknown surface of a master model, we would digitise it on the Zeiss and create spline curves for example, import it into DUCT, create a CAD model and then generate NC codes.

This was a time consuming operation so we chose to look for a dedicated scanning solution.' TIRAC purchased Renishaw's Cyclone scanning system which they found to be significantly quicker than the CMM digitising route.

Ger Reilly explained, 'Cyclone is a very cost-effective scanning system.

It now allows us to produce scanned data, from which we can produce CNC code for machining of electrodes, tooling components or models, returning the CMM to its true role as a measuring tool.' Apart from TIRAC's link with the tool and mould making industry, the Centre produces finished product for the automotive, computer and medical industries.

Here Cyclone offers many advantages with the SP620 scanning probe specifically developed for fine detail and delicate work.

On all Renishaw 'SP' range probes, the stylus deflection and hence contact pressure can be chosen to suit the particular model being scanned.

In the case of the SP620, this can vary from as low as 20gms up to a maximum of 80gms.

This very low contact pressure means that extremely small styli can be used without fear of damaging the model or pattern being scanned.

Ruby ball styli as small as 0.5mm in diameter are used routinely on fine detail work such as coining dies and jewellery applications.

In certain cases ball styli as small as 0.3mm and pointed styli with a 0.1mm tip radius are used.

This virtually eliminates any problems associated with sharp internal corners, often used as a criticism of contact probe systems.

The stepover between scan strips is defined by the user and can be set to any value from several millimetres down to 0.005mm.

This combination of an extremely low contact force together with small styli and a fine stepover allows data to be captured from complex surfaces which is unparalleled in terms of detail, quality and accuracy when compared to other systems.

Consequently, with the correct combination of stylus diameter and contact pressure, it is possible to successfully scan soft materials such as clay and plasticine as Ger Reilly can testify.

'We used plasticine sometimes to hold the product on the table and found that the Cyclone had also scanned the plasticine, as well as the subject matter, which can be made typically from a fairly rigid polymer or steel as with the Crolly dolls head.' Ger Reilly continued.

'Doll making in Ireland is a traditional craft and has recently found the benefits of scanning technology.

To make the porcelain dolls head requires a number of stages.

Firstly, a master model has to be made of the shape and form required.

Secondly, a resin type mould is made from which a clay or plaster of paris model is made.

Around the model they pour a liquid which gives them a flexible mould into which they pour in the porcelain.

On hardening, the flexible mould is peeled away from the porcelain and discarded, resulting in a second master to use over and over again to keep making the flexible plastic moulds.

The problem arises when eventually the second master wears down and the process needs to be repeated.

A variety of sizes therefore demand a large number of moulds.

The objective was to cut out some of the stages and scan directly from the master model to make a significantly harder mould.

This would have virtually no wear and could be used over and over again for the porcelain.

At the same time a 9" doll would require a 75mm head, a 12" doll an 85/90mm head and so on, all requiring individual masters.

Now, with Renishaw's Cyclone system we only require a single master to be scanned, scaling up as appropriate, cutting out multiple costs for master models and so on'.

A further on-going development of the project is to capture historical data from models where no drawings existed and build up a library of these products so that they could be reproduced or totally new products developed.

However, Ger Reilly concluded with an interesting view for the use of Renishaw's Cyclone.

'Consider the point that at an early stage, years and years ago, master models were considered a starting point.

Then with CAD modelling people suddenly decided that everything we were doing with master models we can do on CAD, making master models obsolete.

Now they are going back to the position where they like to be able to see and feel the product, to know that it looks right ergonomically.' However, Ger Reilly points out that although there is a trend back to master models, updated technology such as the Cyclone scanning system has now superseded labourious methods from the past, speeding the toolmaking development process.

As manufacturing industries become more aware of the benefits of reverse engineering, TIRAC is well placed to contribute to the education of toolmaking companies and advanced manufacturing operations, in Ireland and beyond. Request a free brochure from Renishaw ...

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