Most companies involved in manufacturing need to address the issue of how many components to generate in-house and how many components to acquire from outside sources in order to produce a given end-product. On the surface, the idea of out-sourcing a range of different components, and then combining them into a new product, has a great deal of merit. One theoretical benefit is that a company can select the best component for each task, from a range of suppliers, and then assemble them into the best possible end-product. But is the sum of the parts really greater than the whole?

Out-sourcing of components is quite successful in consumer-oriented areas where both the components and the end-products are relatively commonplace. For example, in the automotive industry, most manufacturers would out-source items such as gear-shift selectors, indicator assemblies, instrument panels, headlights, tyres and so on. One reason that this works well is because, despite marketing claims to the contrary, most cars are very similar, as a consequence of ergonomic and aerodynamic considerations as well as market expectations. The other reason that out-sourcing is sometimes successful is because there are many car manufacturers, producing high volumes of similar products, and there are many component suppliers competing for business.

The basic concept behind out-sourcing is that it can enable a company to focus on the efficient production of a core product, rather than "re-inventing the wheel" by developing other commonly available items. Another factor behind out-sourcing is that it is often not feasible for individual companies to produce all the components of an end-product. For example, a company producing passenger aircraft would become unwieldy if it had to manufacture individual rivets, instruments, cloth and foam rubber for the seats, etc. Therefore, a company generally out-sources common items; manufactures those items specific to its core activity and then combines the two into an end-product.

There are however, there are also major problems with out-sourcing, principally because it is difficult to retain control over the design and functionality of the purchased components and the delivery times from suppliers. Therefore, a company that has the luxury of producing all of its key components "in-house" is more likely to maintain tight control over the design integrity, quality and delivery time of its end-products.

The problems with out-sourcing tend to be most significant when a company makes low volumes of complex products which are, themselves, composed of complex components. The more complex a component, the more difficult it is to interface and incorporate into the end-product or system. A good case in point occurs with machine tools. A basic machine tool, such as a three-axis CNC mill, can be built by a company that out-sources key components such as:

• CNC control systems
• Axis servo-drive amplifiers and controllers
• Spindle-drive controllers
• Axis-motors
• Spindle motors
• Slides
• Machine bases
• Mechanical assemblies.

These components are not only commonly out-sourced from other suppliers but, in many cases, from other countries. For example, in a three-axis mill, the CNCs can come from Spain, the servo drives and motors from the United States, the mechanical assemblies and slides from Taiwan and so on. The final assembly is then marketed as a machine tool built in, say, Germany or Italy or the United States, with the implication that the finished product is a unified entity, emanating from the company that assembles the parts.

Some of the above components, such as the motors, are logical candidates for out-sourcing because they are commonplace devices and can be readily interfaced. In the case of basic machine tools, such as three-axis mills or two-axis lathes, even when all the above components are out-sourced from a range of different countries, the result is generally an acceptable end-product that can perform its functions with a reasonable degree of reliability. The degree of interaction between the mechanics and the controls within the machine can be adequately handled through the standard interfaces between modular components. However, the problems with out-sourcing devices, such as CNCs, slides, mechanical assemblies, etc., become far more difficult to resolve when machine tools become more specialised.

In the final analysis, companies need to decide whether they are machine tool builders or machine tool assemblers. Machine tool assemblers are well placed to make high volumes of general-purpose machines such as mills and lathes at a reasonable cost. However, if companies decide to remain as machine tool assemblers, then they face an enormous number of problems when tackling the design and construction of specialised machine tools by assembling a range of mechanisms and controls that have been out-sourced from a number of different suppliers and countries.

A specialised machine tool, such as a computer-controlled tool and cutter grinder, needs to be more than an amalgam of loosely coupled controls and mechanics if it is to function at its optimum level. A sophisticated machine requires a fusion of components, so that the mechanics and controls can act in concert and as a unified entity. This is difficult to achieve by using general-purpose devices in the process because the interfacing requirements are far more elaborate. A sophisticated machine tool has a number of levels of interfacing between:

• The machine base, slides and mechanical axis assemblies
• The motors and the servo-drive amplifiers/controls
• The servo-drive controls and the CNC
• The spindle motor and the spindle-motor-drive
• The spindle-motor-drive and the CNC
• The CNC and other peripheral feedback sensors
• The CNC axis-control software and geometric programming system provided to the user.

All of these interfaces need to be seamless in order for the machine to function but, from the end-user's perspective, perhaps the most important interface is the human interface to the machine. Does the machine appear to be a purpose-built device, optimised for the task at hand, or does it appear to be a collection of components adapted to a task for which none of the components was specifically designed? The answer to this question ultimately defines the design integrity of the machine and hence, its user-friendliness and the productivity that can be derived from it. The core of the problem and the solution is generally in the CNC itself. Endeavouring to interface a general-purpose CNC to a specialised machine-tool can be akin to interfacing a domestic room air-conditioner to a car - the parts aren't necessarily designed to work together as a whole.

ANCA was one of very few companies that could tackle the challenges, associated with sophisticated tool and cutter grinding machines, from a perspective derived after decades of experience in the design and manufacture of both CNCs and machine tools. The company decided that in order to overcome the complexities involved in the creation of such specialised machines, it would have to maintain design integrity over the entire machine. This, in turn, required the in-house design and manufacture of the controls, servo drive systems, slides, mechanics and polymer-concrete machine beds. In simple terms, ANCA chose to be a machine-tool builder that designed and manufactured all of the key elements of its tool and cutter grinding machines within one country and within one high technology facility. This enabled mechanical, electrical and computer systems engineers to work together to design machine tools with unified structures and, most importantly, to ensure that those designs were precisely carried through to the factory floor.

The ANCA System 32 CNC was specially developed by the company in an open-architecture form for integration into sophisticated machine tools. This leading-edge system evolved into an intelligent kernel that provided ANCA designers with powerful interfacing tools that could accommodate complex machine geometries and user requirements. The interfacing in the System 32 provided links into:

• Complex machine kinematics
• On-line modem communications
• High-level graphical user interface elements
• Servo and spindle motor drives
• A range of feedback sensors.

One of the major benefits of the unified approach was that ANCA was able to develop a soft-axis programming system that could provide users with greater flexibility, through additional programming axes, without the added complexity of additional physical axes in the machine tool itself.

The result of ANCA's philosophy is a range of sophisticated tool and cutter grinding machines that have been optimised for their end-applications, to a level which has been hitherto unattainable when specialised machines are driven via general-purpose CNCs. ANCA tool and cutter grinders have become internationally recognised because they behave as purpose-designed, unified entities rather than as an assembly of "re-labelled" parts. However, the real benefits of a unified structure arise through better productivity, reduced down-time and the ability to deal with one whole supplier (with total expertise) rather than with companies that build only part of a machine. In the case of sophisticated machine tools, the whole can be much greater than the sum of the parts.

Buckley Owens Machinery Corp. 6416 Fly Road | East Syracuse, New York 13057 Telephone 315.432.0708 Fax 315.432.0736 Email: info@buckleyowens.com