DRIVES KEEP THE PRESSES RUNNING
July 1st 2004

Replacement of unreliable analogue drives on newspaper reel stands at News International with Mentor II dc drives from Control Techniques, has reduced web breaks and improved feed accuracy for several of the companys huge presses.

Precise synchronisation is needed between reel and web, particularly during reel changeover when the paper is spliced on the fly.

Attention centred on the two crucial drives on each web stand: the main belt drive; and the butt drive that gives close control of the reel when it is almost fully unwound.

Mentor II digital dc drives were chosen for their on-board processing capability that provides a stable digital platform to address problems that had been experienced with analogue drives.

The solution was a 15kW Mentor II for each belt drive and a 4kW Mentor II dc drive for each butt drive. Existing motors were re-used and each drive was fitted with an MD29 Co-Processor module to provide the calculations required for this type of application.

The modules also provide signal routing for other processes and improve performance during crash stop, allowing 300% current for 20sec to maintain the web.

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