Forest Liné machine tools combine turning and milling operations for large complex components.

Advanced technology machine tools in the Forest-Liné range are available in the UK exclusively from the sales and service support specialist, Fortron. UK sales manager, Mark Devall, says: “Forest-Liné has cost-effectively combined the turning and milling operations for large, complex components. This allows OEMs and the tiered supply chain to the aerospace industry, as well as other demanding industry sectors, to finish parts and ship them directly to the customer. The technology not only reduces the initial level of investment required, it also allows companies to operate efficiently on a ‘batch of one’.”

The Forest-Liné range includes high speed milling machines such as the Aero Minumac, Linear Minumac and Vstar, and horizontal spindle milling machines such the Aeromill, Aerostar and Minumajor designed for machining large structural aircraft parts as well as the composite tape laying and fibre placement (tows) Access-Atlas machines used to manufacture ultra lightweight fuselage sections.

The problem

"The technology not only reduces the initial level of investment required, it also allows companies to operate efficiently on a ‘batch of one’"

Fortron UK Sales Manager, Mark Devall

Many aerospace, power generation and petrochemical companies are faced with a dilemma when machining large, hard metal parts. To complete the parts, which are usually complex in form, often requires a sequence of material removing operations such as rough-milling using a prismatic machine tool, turning operations on another specific machine tool, and finally high-accuracy finish operations, which may also require a completely different machine.

Each time the part is moved from one machine to another it requires setting up, which results in lost production time and increased work in progress, not to mention compromising accuracy. The only way to avoid this scenario is to complete all the operations on the same machine and in one set-up. This large part one-hit machining is possible thanks to the advanced functionality available on Forest-Liné machines.

Forest Liné begins by combining a roughing and milling spindle

The first step on this machine technologies evolutionary path was seen in 2003, at the EMO show in Milan, when the company exhibited the 5-axis Easymill head. Equipped with two milling spindles (one for roughing and one for finishing) in a single unit this system provides operational benefits, a significant increase in productivity and a major reduction in the capital investment required because customers can purchase one machine rather than two.

Forest-Liné then developed another version, for turning operations. This time the head combined a milling spindle and a turning tool holding cartridge. This high performance technology has already been tested and proven on a number of customer applications, in the aerospace industry for engine components, as well as for cylindrical parts in the field of machine construction.

This head can mount on such machines as the Modumill (which can be supplied with a 2 or 3 m diameter table), or the Majormill (with a table exceeding 4 m in diameter). This modular construction concept allows Forest-Liné to offer machine tools that exactly match the customers' needs.

Using a turning and milling system

Working with a turning and milling system can be considered in several ways. First, pendulum working which allows the operator access to the turning table to load/unload the workpiece while the machine is working on the other side. The second is independent working when the part is suitable. The part is installed on the turning table which is clamped or released as required for each operation in the process. Milling with a rotary table can be conducted to provide turn-milling capability.

To get to the next logical step that carries the development process to its current stage, the two-in-one head system was increased to a three-in-one alternative, with one head able to change for roughing, finishing, and for turning.