When approached by a global automotive manufacturer, based in India, to assist with improving process and cycle times for its engine cylinder bore machining process, Rigibore’s expertise in the design and manufacture of specialist boring tools was put to full use. Using its in-house developed design software, coupled with its proprietary closed-loop tool compensation system, Rigibore was able to reduce machining time on the cast-iron cylinder blocks.

One of the principal challenges was the common occurrence of size drift on the finished bores, which was caused by material inconsistencies, temperature variation and, of course, insert wear.
Rigibore’s Zenith is said to be the world’s first fully integrated, completely automated boring system, adjusting the ActiveEdge boring bar cutting edges to achieve near instantaneous, precision tolerances without operator intervention. The process transfers the measured value obtained by gauging or probing cycles to the machine-tool control, triggering tool compensation to an accuracy of 1 µm, to return the next machined bore to nominal tolerance.
To streamline the machining process, Rigibore used its in-house RADS design software to create a custom boring tool for the project that would semi-finish to a diameter of 75.68 mm, then finish-bore to 75.934 mm. Additionally, a supplementary chamfering insert cartridge was added to break the edge at the mouth of the bore.
The resulting design featured three semi-finishing cartridges and two ActiveEdge cartridges for the finishing cut. These were positioned in such a way that when the cut was complete, the tool could be offset to provide clearance for a rapid retraction without leaving any withdrawal marks that may have compromised quality. This feature saved around 15 seconds per bore, or one minute per cylinder block.
For further information www.rigibore.com

A Preston-based aerospace subcontractor has benefitted from the technical expertise of Industrial Tooling Corporation (ITC) and its diverse product line-up. Always striving for improvements in a cost- and quality-conscious industry sector, the northwest subcontract company is home to a host of three- and five-axis machine tools from DMG Mori, Mazak and Hurco.

The company challenged ITC with the task of improving upon the productivity of an existing tool on a profile machining operation involving an aluminium solid billet sub-assembly for the aerospace industry. Working against an existing 50 mm diameter shell mill tool from a prominent tooling manufacturer, ITC introduced the Widia VHSC indexable face-milling range, with impressive results.
Cutting data for the existing shell mill with four insert pockets included 11,000 rpm spindle speed, 1700 m/min cutting speed, 4 m/min feed rate and 4.5 mm depth of cut. The new range of Widia VHSC end mills incorporates a proprietary pocket design that enables the aerospace customer to integrate multiple insert radii in one body type if necessary, thus boosting flexibility. Furthermore, the inserts retain their axial positioning regardless of the insert corner nose radius.
This Widia solution was applied with a 2 mm radius insert running at 1800 m/min cutting speed, with a spindle speed of 11,450 rpm and a feed of 0.2 mm per tooth, which equates to 9 m/min. The 4.5 mm depth of cut was retained, although the increased stability of the Widia VHSC is now offering the aerospace customer the opportunity to increase the depth-of-cut to further advance cycle time reductions. However, with an initial cycle time reduction in the region of 50% over a leading competitor, this prominent aerospace manufacturer is already delighted with the savings and extended tool life.
For further information www.itc-ltd.co.uk

New insert geometries have extended the list of suitable applications for the CoroMill 331 milling cutter from Sandvik Coromant.

The latest additions to the portfolio are two light-cutting, periphery-ground geometries for radius inserts to suit applications in the automotive and aerospace sectors.
Unveiled for CoroMill 331 is -M30 geometry, which is designed to optimise the groove milling of steel and cast-iron automotive parts. Available for size 11 inserts offering radius dimensions from 1.5 to 3.0 mm, -M30 geometry is defined by its light-cutting action. This tough geometry is particularly beneficial when machine shops want to boost security in weak set-up or long overhang applications, where it is said to provide reliability and increased competitiveness. Grade availability includes GC1130, GC1020, GC3040 and the latest GC4330 for steel milling.
Another new geometry is -L50, which is aimed at aerospace component machining, as well as parts in the oil and gas industry. Offered on size 11 inserts with radius dimensions from 3.0 to 6.3 mm, light-cutting action is also the principal attribute of the tough and sharp -L50 geometry, making it suitable for materials such as stainless steel, nickel-based super alloys and titanium. Optimised for use in good operating conditions and heavy application areas, GC1040, GC2040 and S30T are the available grade options.
As a point of note, alongside -M30 and -L50, size 8, 11 and 14 inserts with a 4.0 mm radius are being made available as standard in -WM geometry. Again intended to boost the milling of automotive parts, grade options include GC1130, GC1020, GC3040 and GC4330.
For further information www.sandvik.coromant.com

The range of Guhring cutting tools for the machining of composite materials has been expanded with the innovations in a newly published brochure titled ‘High Performance Tools for Machining Modern Composite Materials’.

Available to download from the Guhring UK website or local representative, the 24-page publication includes the latest solid carbide and PCD drills, as well as end mills, taps, slot drills, and PCD compression milling cutters. The Guhring range has been specially adapted to the respective structures of composite materials to ensure optimum chip evacuation, as well as uniform hole diameters across all material types.
Guhring’s latest catalogue introduces new and extended product ranges that include solid-carbide stub drills and Kevlar drills from 2.5 to 10 mm, CR100 and FR100 geometry end mills for CFRP/GFRP, ISO metric machine taps, and 90° and 120° multi re-grindable PCD drills. Additional products include two, three and four cutting edge PCD slot drills and end mills with through-coolant. These tools are available in a variety of shank forms, tolerances, surface finishes, coatings, helix and rake angles, and cutting edges.
Diamond coating is a critical feature for optimising performance when cutting FRP. The Guhring diamond coating is called Cristal, and this is applied in-house to optimise performance, consistency and tool longevity for the end user.
Among the challenges of developing cutting tools for the composite industry are quality characteristics that are important for metallic cutting, but also the fraying of fibres, delamination, burr and thermal damage prevention during machining,
and the splintering of fibres. Guhring has invested significantly in its R&D efforts
to overcome these difficulties.
For further information www.guhring.co.uk

Tungaloy has introduced its DoQuad-Mill, a face-milling cutter that is designed to address interference between the tool and workpiece.

Standard face-milling tools generally prevent end users machining close to walls or fixture clamps due to inclined entry angles, says Tungaloy. In contrast, the DoQuad-Mill has been developed with a near 90° entry angle that ensures the cutter is interference-free and therefore capable of face milling extremely close to walls and other features.
The double-sided square insert incorporates a concave cutting edge profile with a large inclination angle. This design improves swarf evacuation and generates barrel-shaped chips, a feature that prevents swarf re-cutting. The inserts incorporate a large rake angle that generates low cutting forces and a smooth cutting action, thus reducing stress and force on both the machine spindle and cutting tool. This capability makes the cutter suitable for customers operating low-powered machine tools, or working with low rigidity or weak fixture settings.
DoQuad-Mill offers cutter diameters ranging from 50 to 100 mm diameter in either standard or close-pitch insert designation. The standard pitch variant is designed to ensure chatter-free milling, whereas the close-pitch cutter is suited to applications where high-feed and high-speed machining is essential. DoQuad-Mill inserts are available with corner radii of 0.8, 1.2 and 2.0 mm. For precision machining applications that require high-quality surface finishes, a wiper insert is also offered.
The DoQuad-Mill is available with a selection of insert grades and coatings to cater for the machining of various material types. This choice includes the AH3135 PVD grade, which has a high fracture resistance, making it the company’s first choice grade for machining steel and stainless steel.
For further information www.tungaloy.com/uk