Machine tool manufacturer Bavius Technologie GmbH was able to achieve impressive material removal rates of over 20 l/min on its new high-end HBZ AeroCell 160 model with a new generation of high-volume milling cutters from Mapal. The result of this successful collaboration comes at the right time for the aerospace industry, which is taking off again following the downturn caused by Covid-19.

In order to test new machines and at the same time provide customers with references, Bavius carries out milling tests that push them to their limits and beyond. Here, the OptiMill-Alu-Wave, new and improved version of the solid-carbide roughing cutter from Mapal, was selected to showcase the HBZ AeroCell 160. For the tests on aluminium workpiece, the milling cutter with the largest available diameter of 25 mm ran with a spindle power of up to 175 kW, a torque of 66 Nm and a material removal rate of 30 mm.

At a spindle speed of 25,465 rpm and a cutting speed of 2000 m/min, the spindle power was gradually increased. Slot number 6 delivered the best material removal rate with a record-breaking 20 l/min.

“With the 25 mm OptiMill-Alu-Wave, we have achieved a new dimension in aluminium machining,” states Stefan Diem, application engineer at Bavius. “The milling cutter is definitely better than anything we have used previously.”

Bavius used the Safe-Lock system as pull-out protection.

“In this speed range, symmetrical pull-out protection is very important in order not to create imbalance,” explains Tim Rohmer, product manager – solid-carbide milling tools at Mapal. “A Weldon flat, which is often attached to such tools as pull-out protection, is the wrong solution here. To guarantee the smooth running of the machine, there’s no way around careful balancing, even with symmetrical tools.”
For further information www.mapal.com

Allied Machine and Engineering, a manufacturer of hole-making and finishing cutting tools for the metal-cutting industry, is celebrating 50 years of Wohlhaupter’s MultiBore, the world’s first modular boring system. Making headlines in 1973, Allied Machine says that Wohlhaupter’s MultiBore was the first of its kind that allowed users to change boring tools directly at the spindle. While still a best-seller 50 years later, MultiBore now has applications in a much wider range of machining operations.

Until the early 1970s, machine shops used universal facing and boring heads for rough and fine boring. These boring heads had an integrated shank designed specifically for the machine spindle of the corresponding machine manufacturer. However, every machine manufacturer had its own facing and boring heads, even if some of these came from the same manufacturer, in many cases Wohlhaupter. There were no standardised spindle connection points, so users required their own tools for each machine type.

This situation ultimately created demand for universally applicable modular tools. Instead of a one-piece boring head, it made sense to design tools modularly to fit on all machine tools (with different basic holders), while also offering the capability for individual assembly into complete tools adapted to the workpiece. Wohlhaupter implemented this idea with MultiBore and presented the new product for the first time at the Hannover Trade Fair in 1973. Renowned machine manufacturers quickly decided to supply their machining centres with these new tools, marking the beginning of Wohlhaupter’s success story.

Today, MultiBore comes in a complete diameter range of 0.4 to 3255 mm. MultiBore boring tools fit directly into the master shanks, or users can take advantage of intermediate modules to create full assemblies adaptable to the workpiece and fixtures.
For further information www.alliedmachine.com

To improve performance when machining small parts, Mitsubishi Materials is adding a new insert grade to its range of precision turning inserts. Suitable for sliding-head turning centres and intricate machining, the new MS7025 grade is now the company’s insert of choice for small stainless steel workpieces.

The multi-layer nano coating combines a high lubrication layer that boosts welding resistance, with a high hardness layer that suppresses wear progression. The damage caused typically by contact with the workpiece also sees a significant reduction, thus increasing tool life.

Mitsubishi’s high lubrication layer suppresses built-up edge caused by chip welding that tends to occur in low feed and low cutting speed machining. The company performed a comparison test between MS7025 and a conventional grade to assess dimensional changes during the low feed and low cutting speed machining of stainless steel components (SUS440C, DIN1.4125). Results showed a large improvement in dimensional accuracy after machining many parts, thereby reducing the number of insert changes. Another important benefit was the generation of consistently high quality surface finish

The MS7025 grade features a minus corner radius tolerance to ensure precision corner geometry on workpieces. The minus tolerance is available with designations 02M and 04M, which have a precision minus corner radii between 0.15-0.20 and 0.35-0.40 mm respectively. The series is available with two chip breakers: the FS-P for micro through to low depths of cut; and the LS-P for medium to high depths of cut. These chip breakers feature geometries suited to each type; both having a mirror finish polished surface for efficient chip evacuation. They also have high-quality cutting edges that maintain dimensional accuracy and reduce burrs, reports Mitsubishi.
For further information www.mhuk-carbide.co.uk

German cutting tool and insert manufacturer Paul Horn unveiled new products and range expansions at the EMO 2023 trade fair in Hanover last month. Among the highlights was a boring bar with adjustable damping, which visitors could see carrying a grooving insert.

A long overhang can cause a turning tool to oscillate when boring internal geometries. In addition to causing chatter marks on the surface of the machined component, vibrations can lead to a significant reduction in tool life. For unfavourable length-to-diameter ratios, even damped boring bars may vibrate under certain conditions.

To address this problem, Horn has developed a boring bar that can be set to match the oscillation amplitude during machining. Precise adjustment enables vibration-free turning, resulting in better surface quality and a significant increase in insert life.

The damping element, a carbide rod supported in O-rings, is adjustable from the outside by turning a screw to fine-tune the pre-tension of the rings. This capability allows users to set the boring bar accurately to minimise any vibration predicted to occur during a machining cycle.

As standard, Horn offers the boring bars from stock in length-to-diameter ratios of 5:1 and 8:1. Higher ratios are available as special tools. In the case of grooving, Horn can provide the S224 double-edged system. The manufacturer’s BK 224 cassette system ensures a stable interface between the boring bar and grooving insert. To increase process reliability further, the tools have an internal coolant supply.

Markus Horn says: “As a precision tool manufacturer, we not only have to master our own products but the entire machining process, right down to the material being cut.”
For further information www.phorn.co.uk