The production of hand-held measuring equipment often means large batch runs and high demands on product accuracy. In this context, the selected manufacturing technology is faced with the challenging task of working at speed and with a high degree of precision. With this in mind, the solution chosen by Helios-Preisser in Germany is aided by Blum touch probes, which are used in the company’s machining centres for integrating continuous measurements into the process.

In 2008, Helios-Preisser, a manufacturer of hand-held measuring equipment for professional use, became aware that the capacity of its three machining centres was no longer sufficient. The company was operating around the clock in three shifts to manufacture its micrometers, vernier calipers, dial gauges, and marking and measuring instruments. Due to its positive experience with the company’s existing machine tools, Gammertingen-based Helios-Preisser opted to continue relying on machine tools from Heller fitted with Blum Novotest measuring systems.
A 14-m long pallet magazine connects the company’s machining centres, which are supplied with clamped workpieces by a robot. Helios-Preisser employees already had many years of positive experience with Blum touch probes in the company’s previous Heller machining centres, which still operate with great reliability. As a result, a new Heller four-axis machine was also specified with a Blum measuring probe.
Only the company’s five-axis machining centre used a probe from another manufacturer, a fact that did not meet with great approval at Helios-Preisser. “Where possible, I endeavour to make regional purchases. In Blum, we have found a partner that can offer us high-quality products and corresponding service from a close distance – we like to have just one point of contact,” emphasises CEO Siegfried Lorch. “In addition, we have been extremely satisfied with the Blum touch probes for many years.” As a result, a Blum probe has since been fitted to the five-axis machining centre.

With 120 employees, Helios-Preisser uses TC50 and TC60 touch probes from Blum. The former transmit data via infrared, the latter via radio technology. Each touch probe is fitted on a tool holder and can be substituted if necessary in order to execute measuring tasks before, during and after machining. The infrared system can be used when line-of-sight can be guaranteed between the touch probe and receiver. A measuring system with radio transmission is installed on the five-axis machining centre, which reliably transmits the signals from the touch probe to the receiver – even when the line-of-sight is disrupted by the large swivel head.
Blum touch probes are used for a whole range of tasks at Helios-Preisser. For example, they check whether the workpieces are clamped correctly prior to the commencement of machining. “We also use the probe to measure the result of machining,” says Tobias Weber, foreman of the milling shop. “After casting, the dimensions of cast blanks are often very different, which is why, prior to machining, the position of the blank is captured using the probe, with compensation values for the NC program transmitted to the machine controller. Thanks to the Blum touch probes, we have been able to reduce the rejection rate for these components from 10% to 1-2%.”
Another example is the tailstocks of the company’s bench metrology centres. Here, a hole must be positioned accurately to 0.01 mm for a channel on the same part. Previously, there had always been fluctuations, often due to the temperature response of the machine. If the dimension was correct in the morning with a cold machine and shop floor, by noon, with a hot machine and warm weather, the dimension would be out of tolerance. The channel is now machined and measured before finally being drilled using the measurement data. This strategy enables the desired precision to be reliably achieved regardless of temperature.

The large volumes manufactured in Gammertingen require short cycle times, so measurement must not take too long. Blum touch probes are designed for maximum measuring speed and are not sensitive to coolant, which is simply pushed away by the high measuring pressure. Measurements can also be taken directly after machining.
“The touch probe is moved at a top speed of 60 m/min until close to the component; touching then takes place at up to 3 m/min – so not much time is lost,” reports Weber. “After machining, we check almost all fits using the Blum touch probe.
“Our manufacturing process has now become so precise that we no longer have to grind many parts. Previously, numerous components were milled with an allowance and then ground to the finished size in order to achieve the required precision for our measuring equipment.”
If a machine determines that a tolerance has not been held, the pallet is automatically removed and placed in the company’s pallet store with an inspection record. The next morning it can be inspected to determine where the fault is and, in the meantime, the machine can continue to process further pallets.
With respect to unmanned production, the touch probes from Blum have completely proven themselves at Helios-Preisser. “Overnight, and often for parts of the weekend, the machines run unmanned,” confirms Weber. “We only operate one shift, but we produce more than we did previously in three shifts.”
Lorch concludes: “The systems run reliably during unmanned operation, which relieves the pressure on us and makes it possible to manufacture the required volumes without needing a night shift. Blum probes are essential to unmanned operations, especially as we are also very satisfied with the service offered by the company.”
For further information www.blum-novotest.com

Zinc and aluminium high-pressure die-casting specialist, RD Castings, has used Japanese-built, high-speed, twin-pallet machining centres from Brother since 1989, and currently has nine of them adding value to its products in two machine shops in Mildenhall. Since the mid-90s, the 30-taper machines have replaced manual milling, drilling and tapping, which was both labour intensive and subject to quality variation.

Running the company are siblings Anthony and Michael Pateman, who were interested when Brother’s UK agent, Whitehouse Machine Tools, suggested they see a demonstration of the new ISO control with 12” colour LCD screen, the CNC-C00, a significantly faster and more user-friendly CNC system fitted to its latest machines.
After they visited the agent’s Kenilworth showroom and technical centre, they came away not only with up-to-date information on the new control’s capabilities, but also having ordered another Brother machining centre, a Speedio R650X1 with Nikken rotary 4th axis. It was not their intention before the visit, but the machine was so productive and such a good fit for RD Castings’ needs that they placed the order on the day and invested in a second identical model within six months.
Numerous facets make the machine particularly applicable to machining light castings, one being its outstanding speed. Workpiece changeover is completed entirely within the 3.4-second rotation of the twin-pallet ‘Quick Table’, while the 21-pocket magazine’s 0.9 second tool-change time, 50 m/min rapids in X Y and Z, and rotation of the 4th CNC axis, are carried out simultaneously.
The first tool is ready to cut the next component immediately it arrives in the machining area, and little time is wasted on each subsequent exchange of the cutter due to the rapid tool-to-tool time and spindle acceleration from zero to 16,000 rpm in 150 ms, with similarly fast stop time.
“The speed of tool change on the R650X1 mirrors that of our Brother 324N and R2A models, where the tool carousel encircles and travels with the spindle, which does not have to move away to pick up a new cutter as on the Brother TC32A and 32B machining centres that we also have on-site,” explains Michael Pateman. “It results in very high productivity that is enhanced by faster processing of existing programs in the new CNC-C00 control. For example, we recently reduced a 3.5-minute cycle by 20 seconds with no change to the original program. If we are machining say 20,000-off parts annually, the saving runs into thousands of pounds.”

Anthony Pateman pointed out another advantage of the R650X1; the generous axis travels of 650 x 400 x 305 mm in X, Y and Z. The table accepts RD Castings’ 500 x 350 mm base plates on the trunnion fitted to both machines, allowing multiple components to be fixtured for two- and three-axis machining, relieving the load on the 324Ns and R2As, which are always filled with work.
He adds: “There is a trend towards larger castings these days and we have just installed a 500-tonne casting machine to meet the requirement. In order to perform machining, the ability of the R650X1 to swing our 400 mm diameter parts in the rotary axis means that we are often able to finish these bigger castings in one hit and save on a second set-up operation, which hugely decreases the cost of production.”
To underline this comment, he points to a casting of about the size that used to need a second operation but is now machined in one four-axis process, saving 70p per part.
Simon Hale, CNC machine shop manager, stated that the productivity of another part – an aluminium die cast housing for the rail industry – has been nearly doubled using the larger machine compared with the other Brother models featuring similar tool carousels. Some 17 castings per hour were drilled and tapped using 12 tools on the latter machines, whereas with a trunnion fixture on an R650X1, 32 parts per hour come off the machine after each pallet rotation. Furthermore, just eight tools are needed.
The increase in output is partly because, by routing coolant at the uprated 30-bar pressure on RD Castings’ latest machines through an indexable-insert drill rather than employing a twist drill, it is possible to produce larger holes above 18 mm diameter in one spindle movement, rather than having to spot and then peck drill the holes multiple times.
Michael Pateman asserts that manufacturing costs are increasing in Asia while the lower pre-Brexit value of the pound is helping UK competitiveness.

He sums up: “By employing ultra-high speed machining techniques on 30-taper rather than 40-taper machines, with extensive use of PCD inserts clamped in dynamically balanced tool holders, the cost of producing a casting is now about the same in Mildenhall as it is in China – and we are winning back business as a result.
“The latest Brother Speedios with their larger working envelope have added considerable versatility to our shop floor, as they can economically machine anything from the simplest, smallest casting up to the largest and most complex. Productivity is also up due to the faster control and by allowing more flexible production planning.
“All of our Brother machines work flat out eight hours a day and their speed, accuracy and reliability are fantastic. Coupled with the high level of support from Whitehouse, it has been an unbeatable package for us.”
For further information www.wmtcnc.com