Flying shear developed using Siemens servo motors and controls

HMK Automation & Drives has developed an end-of-line flying shear crosscut and sheet stacking system for CM Machinery. The equipment, which is based around Siemens servo motors and controls, forms part of a 500,000 multifunctional plastic extrusion line for a leading Swiss manufacturer.

Manufacturers are increasingly seeking flexible equipment that can be set up automatically and monitored remotely from a central station in order to cater for short production runs. HMK believes that Siemens' motion control systems are well matched to the needs of complex production lines comprising individual machine stations sharing common control systems. HMK, part of the Entologi Group, describes itself as the largest independent UK supplier of motion and engineered drive components and systems to OEMs and factory automation integrators. Moreover, HMK is Siemens' Technology Partner for motion and engineered drives and systems.

Liam Quinn, CM Machinery's Technical Sales Manager, states: "Our customer did not specify Siemens for this project, but it was apparent that the application required a high level of flexibility to cater for the different products that were to be made on the line. Just as important was the close integration required between the processing stations on the line, so that fast machine set-up times could be achieved. The Siemens motion control system had the flexibility and visibility to provide for these needs. Mike Jordan at HMK is a Simotion programming expert and he has been able to create a flexible system with a MP377 operator interface that allows easy alteration of programmes and products with the simple addition of presets. This kind of flexibility is vital for plants that operate 24 hours a day, 365 days a year."

Tight tolerances

Material will be fed down the new production line in a continuous 2.5m wide board. A trim station with circular saws cuts the product to finished widths and trims the outer edges. This is followed by a travelling crosscut whose controller enables it to move at the same speed as the product while cutting. Accuracy in length cutting is critical, therefore tight-tolerance control of the cutting axes has been essential in ensuring the boards meet final customer requirements. The finished boards are then transferred out of the cutting area by horizontal conveyors in a predetermined pattern that enables them to be lifted by an overhead vacuum frame and placed onto pallets for final packing and despatch. The stacker frame operates with two servo axes, enabling the boards to be lifted from the transport conveyor and moved to one of two stacking tables, giving an offloading facility while the line continues to operate. The machine is fitted with a number of ET200S remote I/O stations. CM Machinery built all the hardware for this triple-function machine.

Quinn comments: "The end user has placed great emphasis on safety, so we specified that HMK should design safety zoning onto each of the machine's separate functions - no mean feat on a multi-axis servo system. Another specified requirement was the ability to change any of the servomotors during normal maintenance in one of the safety zones whist the other safety zones remained operational. This feature was successfully developed, tested and accepted by the final end user. This project has led to a level of development for both HMK and ourselves - this seems to happen each time we work together."

Motion control

Northern Ireland-based CM Machinery has been working with HMK for several years designing and building multifunctional machine tools for use with multinational manufacturers based in Scandinavia and Northern Europe. Their machines generally operate on a 24-hour duty cycle.

Controlling all motion and machine sequence control on the machine is the Simotion D435 motion control system. It integrates motion control and automation control functions into one unit and was specifically designed for applications with complex movements. Simotion D combines the complex operation of motion functions into a scalable motion control system for various hardware platforms, thanks to a common engineering system, thereby providing for considerably more flexibility for machine planning and construction.

CM Machinery has met its customer's delivery timescale for the supply of the bespoke end-of-line equipment and it will become operational later in May 2011.