Casting directly from a computer model
Finnish method offers major savings and speeds up product development

The patternless casting technique developed by VTT (Technical Research Centre of Finland) offers companies up to 35% savings in product development costs. Additionally, the time required for product development can be reduced by as much as two months. Such savings in time and money are of major importance to the competitiveness of workshops also on the international market.

High resolution image Photo: Jukka Väinölä

In reality, patternless casting is based on a robot that prepares the mould directly from a CAD model. Additionally, the shape of an object can be derived from an existing spare part or an artist's model. Then the The model is converted into control data that steers the robot manoeuvres. The system operator directs the robot to machine the shape of the casting into the mould, which is made of hardened sand. This mould is then cast as in the normal way. When the test casting is satisfactory, the robot can be used for making the actual casting tools for serial production.

With VTT's technique, prototypes and products can be quickly cast from the right materials and submitted to designers for approval and subsequent testing. As a result, the time required for design and manufacture can be reduced by up to two months because there is no need to make the pattern. At the same time, the development costs of cast products decrease by 10 to 40%.

In laboratory conditions, VTT has achieved even greater savings in time and money. A trial study was carried out to determine the time and outlays required for making cast components for a hydraulic hammer. The study was completed using both conventional casting techniques and the patternless casting method developed by VTT. With conventional techniques, the total cost of bringing the prototypes of the cast hydraulic hammer components to the market was € 38,300 and the process took 17 weeks. With VTT's patternless casting method, the total cost was only € 4,000 and the time required 5 weeks. Two prototypes were produced in both cases. Consequently, the time required by the new technique was only one third of that of the conventional method while the costs were almost 60% lower.

Moreover, the shape of the objects to be cast is not restricted in the same way as with conventional techniques. Now the buyer can test and experiment with the product prototypes more freely as the cost of making the pattern is eliminated. This method could be easily expanded to plastic injection moulding and other areas of manufacturing that deals with complicated shapes and extreme dimensions.

Another advantage of the new technique is that it improves occupational safety because the casting mould is made in a closed robot cell, which prevents the migration of carcinogenic particles into respiratory organs. Additionally, emissions can be considerably reduced as certain dust particles are removed from the indoor atmosphere in the foundry.

Additional information:

Photo: VTT

VTT Industrial Systems Matti Sirviö, Product manager Tel. +358 9 456 5586, +358 500 514 531 matti.sirvio@vtt.fi