System 3R Refix reduces mould-making from weeks to hours

Citation

(1999), "System 3R Refix reduces mould-making from weeks to hours", Aircraft Engineering and Aerospace Technology, Vol. 71 No. 1. https://doi.org/10.1108/aeat.1999.12771aab.007

System 3R Refix reduces mould-making from weeks to hours

System 3R Refix reduces mould-making from weeks to hours

Keywords Moulding, System 3R

It is reported that System 3R's Refix reference system is making a major contribution towards reducing mould tool manufacturing times from three weeks to just 24 hours, at the TRW Group's three "centres of excellence" in Europe, the USA and Asia (Plate 3).

A global player in the automotive, space and defence industries, TRW were consistently finding that 40 per cent of the time required to manufacture a tool was associated with their zero added value mould frame. As a result, one of the group's engineering teams was set the onerous task of making dramatic time savings at their three main manufacturing centres, while at the same time maintaining a high degree of repeatability and production flexibility.

Plate 3 System 3R's Refix reference system has provided accurate work holding for TRW, together with flexibility for fast "jobswap"

And, to make any new technology that was initiated work efficiently around the globe, it was vitally important that the experience and knowledge of the Group's existing toolmakers was fully shared between common CAD stations at the three centres.

After some intensive research and a thorough review of the options available, the team resolved that there was maximum benefit to be gained by investing £1m in three Mazak vertical milling machines, an Okamoto grinding machine, an Ixion gun drilling machine, all "linked" by the System 3R Refix reference system.

According to TRW, using this set-up, it was found that three engineers operating on a single shift basis, and even with only half the equipment commissioned, could complete a mould frame in less than seven days ­ half the time it had taken previously. With the equipment fully commissioned, plus further adjustments to the machine technology, manufacturing time was reduced to a staggering 24 hours, without cutting corners or sacrificing any quality and precision.

To achieve maximum productivity, System 3R Refix, based on X and Y referencing (and electronic zero point), was found to be the most accurate workholding system capable of providing fast, off-line set-up times, plus the ability to move workpieces between processes as an integral unit. Also it afforded the essential flexibility which allowed machining cycles to be interrupted and restarted, to accommodate the introduction of other "emergency" jobs into the work schedule, whenever this became necessary.

Working closely with TRW under System 3R's "One System Partner" arrangement, the suggested time-saving mould production solution is based on 3Refix reference tables, cubes and T/angle shelves with a modular pattern of 20µm diameter holes on a 100 × 100mm pitch. Each hole, within this grid pattern, is designated by an alphanumeric code: A1, A2, B1, B2. and so on. Accessories such as a vice, chuck, pallet or bespoke workholder also have two corresponding 20mm diameter reference holes.

At the heart of the interface between the substrate and accessory is a 3Refix patented expanding mandrel which, compared with lining up conventional solid dowel pins, provides a repeatable positioning accuracy to within 0.005mm. Also, they are more easily inserted and removed, there is less wear and tear on the reference holes and larger variations in reference holes can be easily accommodated.

The system's accuracy and repeatability during milling operations means that subsequent grinding allowances can reportedly be reduced by as much as 50 per cent, which represents a considerable time saving.

With a machine tool, where the reference points are known relative to the electronic zero point, this information can be included in CADCAM software, enabling set-ups to be simulated on screen before committing to layout. Ultimately, drawings can be printed showing the entire set-up information for the machine operator, who then carries out the instructions and starts the machine.

System 3R's "One System Partner" arrangement provided all the relevant technical know-how and experience for TRW engineers to achieve their highly successful goal. Indeed, under the scheme. the company's highly motivated engineering staff are always on hand to help advise on the best, most economical solution to furthering a "creative productivity" approach to manufacture.

Further details are available from System 3R (UK) Ltd. Tel: +44 (0) 1844 274455; Fax: +44 (0) 1844 342296.