Clever system combination

Digitisation has already been incorporated into CNC machine workshops in many sectors in a variety of ways. Tool manufacturers are also striving to transform the advantages of exchanging digital data into immediate user benefits. Michael Renz, head of the actuating tools product line at CERATIZIT in Besigheim, is in no doubt of the benefits: "The future lies in intelligent tools that can independently monitor and correct themselves. This makes machining more flexible, safer, more precise, and more cost-effective."

Renz is therefore continually driving forward the digitisation of ‚his‘ mechatronic actuating tools and is looking for partners to aid in the development of new tool solutions. He has found the ideal partner in Blum-Novotest GmbH, a renowned manufacturer of innovative and precise measuring and testing technology: "We have already worked well together on a customer project with our U-axis several years ago, and more recently on the government-funded BaZMod research project into optimised energy and data transfer between the machine and tool."

It was during this project that the idea for the KOMflex precision spindle head was born. Its special feature is an integrated wireless unit that can exchange bidirectional data with the machine control system via the BLUM standard wireless interface. This results in closed loop operation consisting of machining with the KOMflex, measurement with a measuring stylus, for example, as well as correction of the cutting edge position – and thus automatic diameter correction of the precision tool in the spindle. The desired outcomes are reduced downtimes from incorrect manual intervention, shorter machining times, and increased transparency and economic efficiency.

Tool and measuring technology expertise combined

For the new precision-spindle head, docking a communication unit was not sufficient. This became apparent in initial preliminary discussions and tests in CAD, explains Markus Majer, key account manager for measuring components at Blum-Novotest. "If we had only put together standard components, the result would have been a product that was too big and bulky. For this reason, we worked on a new concept together that allowed us to combine the tool, wireless and battery units in an optimum manner. The cooperation was extremely goal and product-oriented, with a result that we are all happy with."

The KOMflex precision spindle tool turned out to be very compact with an outer diameter of 63 mm and length of 100 mm. "It is 20 mm shorter than in the initial plans," enthuses Markus Majer. "This compact design sets the system apart from similar products from other suppliers, with its greatest plus point being automated control via our RC66 wireless interface." This means that µm-precise machining can be performed through operation in a closed, unmanned loop over a long period.

The automated operation of the precision spindle head also increases safety for the operator. If intervention is necessary for measurement and correction purposes, this is not only unpleasant due to dripping coolant, but it is also associated with a high risk of slipping in the case of large machines.

High performance with a compact design

The KOMflex precision spindle head weighing just 1.5 kg features an ABS 50 adapter as the interface to the machine. The ABS 50 interface offers a major advantage as it can be flexibly adapted to a wide range of machine interfaces, such as ABS50 to HSK-63A. A combined interface is available for cutting tools, which consists of ABS 32, a cylindrical adapter with a diameter of 16 mm and a toothed surface for bridge tools, etc. This means that the full KOMET spindle kit from CERATIZIT can be used.

Yet the impressive technical data does not stop there: the KOMflex operates at speeds of up to 8000 rpm and ensures positional accuracy to 0.001 mm in radius. The adjustment range is +-0.25 mm. Depending on the tool, holes with a diameter between 1 mm and 120 mm can be machined. A battery compartment is integrated into the housing with IP67 protection class, which holds two easily replaceable batteries that deliver the power for over 2000 correction cycles.

The KOMflex precision spindle head is extremely robust thanks to its maintenance-free drive. The patented central alignment of the motor and its surrounding ring PCB mean that the cutting edge can be adjusted even at speed. The developers purposely dispensed with imbalance correction, as this would be associated with a greater mass and additional tilting moment. Michael Renz explains: "Due to the central alignment of the boring bars, imbalance correction is not necessary." In addition, the spindle head can be precision-balanced if required.

The KOMflex is usually controlled via the machine control system. For this purpose, it contains a BLUM wireless unit with a range of up to 8 metres, which communicates with the RC66 wireless interface integrated in the machine. The KOMflex features a manual mode for pre-setting, in which the head can be adjusted using a magnetic pin and two magnetic sensors. This unit is surrounded by a non-magnetic steel ring, which provides the spindle head with high stability.

Michael Renz is impressed by the short payback time: "Through the automated machining processes that are now possible alone, such as the machining of bearing seats or highly precise cylinder bores, our new precision spindle head delivers a return on its investment very quickly, especially if the BLUM RC66 wireless interface is already present in the machine tool." Markus Majer adds: "That is often the case, as we are among the OEMs for many major machine tool manufacturers when it comes to our measuring styluses and the RC66."

If a measuring stylus from another supplier is already installed or external measuring computers are in operation, the new KOMflex precision spindle head can also communicate with these components. All they need is the RC66 wireless interface, which can also be retrofitted.

Best experiences from in-house production department

CERATIZIT can now draw on experience from its own production lines, as the KOMflex has already been in use for several months at the KOMET factory in Besigheim for precise machining of ABS holes. Production employees have confirmed to Michael Renz that they are now able to reliably comply with the specified quality requirements more quickly. "You no longer have to stop the machine to take measurements on the workpiece and to readjust the precision adjustment head if necessary."

CERATIZIT can demonstrate the advantages of the KOMflex precision spindle head for customers and interested parties in the test and demonstration rooms of the Besigheim factory, as the Heller HF5500 5-axis machining centre recently put into operation is equipped with all relevant BLUM components. For Michael Renz, this high-precision machine is the ideal basis for demonstrating the capability of his actuating tools on various test and customer components: "The HF5500 is prepared for use with our new KOMflex and the KomTronic U-axis actuating tools."

It is also important at this point that the RC66 interface is able to control up to 16 different KOMflex tools. "This may be favourable for the machining of a complex bearing plate, for example, in which various bearing seats must be machined. Several wireless interfaces only need to be installed for multi-spindle operations, since the signals must be available at the same time," explains the head of the actuating tools product line.

BOX

Advantages of the new KOMflex precision spindle head from CERATIZIT

• Intelligent diameter correction via BLUM wireless interface (RC66)
• µm-precise processing in self-adjusting automatic mode (closed loop)
• Adjustment range: ±0.25 mm in radius
• Boring range:
  • Internal machining: Ø 1 – 120 mm
  • External machining: Ø 5 – 75 mm
• speed: 8,000 rpm in centre position
• System application:
  • Temperature compensation, e.g. in the case of aluminium
  • Compensation of cutting edge wear, e.g. in the case of steel
• Compact design
• Robust thanks to maintenance-free drive
• Manual intervention via the machine control system possible
• Manual pre-setting via magnetic pin possible
• Prevention of operating errors through in-process measurement
• 1 µm positional accuracy in radius
• Absolute path measurement system on the adapter
• Thro‘ coolant supply up to 30 bar
• ABS 50 universal interface
• Commercially available battery, easily replaceable, for over 2000 correction cycles