CNC Information | CNC Books | CNC Videos

Producer of low volume reaction injection moulded parts and polyurethane castings uses five vertical machining centres to cut master pattern equipment from polyurethane tooling board

The Midas Pattern Company specialises in the production of low volume, high quality reaction injection moulded (RIM) parts and polyurethane castings (PuR). The company intends to dramatically shorten the time and cost for a designer to move from a CAD model to a fully functioning prototype/finished usable component.

The production material has to validate design and produce a saleable product.

Midas uses five Haas CNC vertical machining centres (VMC) - typically to cut the master pattern equipment from polyurethane tooling board.

Midas said that one of the main reasons for choosing Haas CNC machine tools was reliability and user-friendliness.

Based in Bedfordshire, UK, the Midas Pattern Company was established in 1989 as a precision foundry toolmaking company.

The company has developed into a substantial business integrating CADCAM and CNC toolmaking techniques with traditional pattern and mould making skills.

Managing director of Midas, Alan Rance, said: ‘We aim to dramatically shorten the time and cost for a designer to move from a CAD model to a fully functioning example of a new product - not just a prototype, but a finished part, made from production material that not only validates design but is truly saleable in the market place’.

Midas uses a novel composite tooling system, MRIM, which offers a production moulding technique that can produce quantities from 1 to 5000-off.

Midas said it is ideally suited for making large parts or components with multiple assemblies and complex features.

Rance said: ‘We make parts in the production intent polymers that enable our customers to produce low volume examples of new and prototype products without incurring the very high cost of metal tooling or the compromises in functionality and mechanical properties you expect with traditional RP techniques’.

Based on RIM and PuR, the company’s FASTrim service offers a competitive alternative to SLLS/Silicon and VAC casting.

FASTrim can provide finished parts in as little as 10-15 working days, using cast PuR and soft tooling CNC machined directly from 3D CAD data.

Typical customers include medical technology companies building low-volume, high value instrumentation - machines that can cost hundreds of thousands of Pounds each but are usually built in low numbers.

* About RIM - Rachel Collier, Midas’ technical sales manager, said that reaction injection moulding, utilising MRIM tooling is ideal for the instrumentation industry.

She said: ‘Customers may only want to produce between, say, 10 and 20 finished products a year.

For example, if a customer designs and builds a new mass spectrometry machine costing many thousands of Pounds, it wouldn’t make sense to lay down metal tooling suitable for thousands of parts when you only need a few’.

Many of today’s medical equipment manufacturing companies are relatively small - often founded by individuals departing larger organisations - and perhaps only aiming at niche markets.

As recently as 20 years ago, such companies probably wouldn’t have existed without the patronage of a corporate benefactor - a large, well-financed parent organisation, for example - or some other significant investor.

Developing a new product was hugely and prohibitively expensive.

These days, even small firms can use the services of companies like Midas Pattern to get their products to market at a fraction of the traditional cost and to compete head-on with the big, well-funded players.

‘We’re not a typical plastics company so we’re not obsessed with high-volumes,’ said Collier.

‘We’ve taken all of the techniques and the principles we’ve learnt in the very specialised foundry pattern-making sector and applied them to making high quality plastic parts in small numbers’.

The Midas process starts by building tooling models within CAD (Computer Aided Design).

From these CAD models complex CAM (Computer Aided Machining) software is used to generate cutter paths.

The code for these paths can then be downloaded to one of the company’s five Haas CNC VMCs.

The VMCs include a 12,000 rev/min spindle VF-4SS, a VF-6 with a 4th axis Haas rotary table.

There is a a large 2m x 1m VF9.

The machines typically cut master pattern equipment from polyurethane tooling board.

‘Once we have the master pattern equipment we then use it to produce a composite metallised resin injection mould tool - MRIM,’ said Collier.

‘That’s about as much as I can tell you.

The detail of the process is a closely guarded secret’.

She added that the skill - the ‘Midas touch’, one could say - is being able to make a good quality tool from the master pattern.

Each of the company’s CAD engineers is also a machine setter, programmer and operator, so when it came to choosing a CNC machine tool, said Haas to manufacturingtalk.com, top of the list of essential criteria were reliability and user-friendliness.

Thanks in part to the precision of the master pattern equipment, Midas MRIM Tooling is guaranteed to produce up to 5000 parts, which is usually far more than a customer needs but does allow them to be used for intermediate production volumes.

A typical mould is around a 1m3 in size, which in the world of mainstream injection moulding would be considered extremely large.

Collier made the point: ‘If you made a hard tool for a part of that size it would cost around 10 times more than one of our composite moulds.

We can also achieve the complexity but without having expensive mechanical movements’.

* Pattern making - pattern making is a labour intensive process, so Midas still relies on its own knowledge workers - skilled pattern and toolmakers - as well as its state-of-the-art machines.

To keep them all busy, the company supplements its core business with a range of other activities.

The Bedford factory, spread across two adjacent sites, is essentially a tool making facility, which produces foundry patterns, jigs and fixtures, rotational mould tools, inspection fixtures and exhibition models.

It also houses a number of Low Pressure RIM moulding machines producing low-runs of finished parts.

‘What all Midas products have in common,’ concluded Collier, ‘Is that they all start with CNC machining, which means that every time Midas delivers a tool or a finished part odds are it started life on a Haas CNC machine tool’.

* About Haas Automation - Haas said that CNC machine tool companies have led the ‘democratisation’ (or freeing up - Ed) of manufacturing production, perhaps none more so than Haas Automation itself, which claimed to be the original low-cost, high-specification machine tool builder.

Founded just twenty years ago in California, USA, but already with more than 85,000 of its products in operation around the world, Haas said it has certainly played an important part in getting affordable, reliable tools in the hands of the ‘industrious and the ingenious’, helping companies like Midas Pattern Company to ‘turn bright ideas into gold’.