What makes a good measurement solution for the shop floor?

Fast response times and direct feedback make a production-integrated metrology attractive. For the solution to be successful, mechanical engineering, ergonomics and service must result in an overall concept that is fit for the future.

Published in Quality Engineering Plus (in September 2020)

For some time now, metrology has been undergoing a change from the measuring room to the manufacturing environment or the fully automated production line. The exciting question now is, what does this mean for the measuring machine? Or to put it a little more broadly: What does this mean for the measuring solution in the future?

Many manufacturers appreciate the advantages of measurement in production. The material flow is easier to handle, the result is available much faster to the people who can intervene immediately - the workers. This reduces scrap, as the worker can already counteract trends before it is too late.

What distinguishes manufacturing from the measuring room?

The requirements of production differ in important aspects from the quality area, especially the operation, the environment and the required reliability. Ideally, the worker carries out the measurement himself in the vicinity of the production machine. Simple operation and an immediately available, easily readable result leave time for the essentials, the production. This is where the software comes in, with intuitive operating elements and clear reports and trend analyses. There are already solutions that distinguish between programmer and operator and partially automate programming.

Go with the flow

For short distances, the measuring machine is close to the production machine and thus a small footprint is mandatory. With modern manufacturing methods and design technologies such as topology optimisation and FEM simulations, the machines can be extremely compact and light and the control and electronics can be integrated into the machine.

A modern production measuring machine is optimised for minimum floor space (here just 2.3 m²) and ergonomically designed for easy operation.

But it is often the little things, such as a cleverly integrated probe changer for maximum measuring area, that make the difference for the operator. In the case of gantry machines, for example, a level finish of the base plate on all sides can be crucial for easy loading. This makes it easy to integrate the machine into the existing hall in any orientation.

metrology in step with manufacturing

In manufacturing, the cycle determines the speed, whereas until now the focus was on accurate and traceable measurement. How do you deal with this now, because the more precise the measurement, the more time is usually needed? Fortunately, there are high-precision measuring systems that can map the measurement via the very fast head movement and optical sensors that measure large areas extremely quickly with sufficient accuracy.

Schematic classification of the measuring systems according to speed and accuracy.

And if this is still not enough, you can use a fast comparator or operate the measuring machines in a faster mode. Here, repeatability is maintained and trends can still be observed. The measurements are matched against accurate absolute readings in random measurements.

The future - Life is what happens while you're making plans

Production is also changing profoundly. Rapid series changes and demographic change are fundamentally altering the framework conditions. It is therefore important to find a sustainable solution:

• Flexibility
  Retrofittability for sensor technology and easy change of location offers adaptability in a new series
• Automation capability:
  Pre-configured automation solutions from the manufacturer or pre-equipment make the machine easily expandable
• Monitoring capabilities
  Online monitoring tools are already standard and provide the basis for predictive maintenance

Reliability through excellent and plannable service

The most beautiful machine is of no use if it stands still. Particularly in manufacturing, one is used to planning with high availability and to depict this reliably and predictably through service contracts. In the end, it's the overall package that counts: of course, an attractive purchase price is important, but at least as important are reasonable operating costs (cost of ownership) and availability as soon as the machine is in regular operation.

In addition to reliable mechanical engineering, worldwide availability of parts, manufacturers already offer modular service programmes that offer many advantages:

• Current software
• Guaranteed response time
• Plannable costs
• Extended guarantees

It is precisely these aspects that accompany the user in everyday operations.

Robust mechanical engineering

The manufacturing environments we encounter at our customers are as diverse as the parts themselves.In machine design, we pay attention to some new aspects in workshop-ready machines compared to the measuring room.

• Temperature behaviour:
  The choice of material and connection of the individual components is essential for the machine to change as uniformly as possible. The residual errors are then recorded in the climate chamber in elaborate measurements (see illustration) and can be calculated out by compensation during measurement.
• 24/7 operation:
  Here, the most tried and tested and robust drive and guide systems possible are used. The installation position can also be decisive for dirt resistance, such as vertical mounting of the measuring systems and protected drive rods (see illustration).
• Vibrations:
  Many years of experience with customers show that air bearings are also suitable for the production environment. In difficult environments, air-sprung, active damping or particularly robust linear guides are used.

Left: A production measurement solution undergoes extensive tests in climatic chambers and vibration measuring stations until it is fit for the workshop. Right: Small details matter, such as protected scales and drive units. The installation position also plays a role.

There is no single solution here, which is why we and other manufacturers offer a whole portfolio of machines and options.

In the end, the package decides

Of course, high-quality mechanical engineering with sensor technology tailored to the respective application is a prerequisite. In order for this to become a well-rounded measuring solution, important points must be added:

• Ergonomics: The solution is efficient when it fits into the material flow
• Operating concept: The worker can operate the solution reliably
• Future-proof: the machine is easily adaptable to new processes and expandable with modern sensor technology
• Cost-Of-Ownership: Reliable and plannable service with modern software makes everyday life easier

If the package is right, you will enjoy your measuring solution.