JDR Cables in new drive to increase production

Drives from Control Techniques have played a central role in the major upgrade programme at JDR Cables in Littleport, Cambridgeshire.

Drives from Control Techniques have played a central role in the major upgrade programme at JDR Cables in Littleport, Cambridgeshire.

The networking and programming capabilities of Mentor DC and Unidrive AC drives have simplified the design of critical machine upgrades and increased production output, as well as extending production capability and versatility.

This world-leading manufacturer of cables and umbilicals has now virtually completed its multi-million investment, which includes a brand-new 10,000m2 factory and the upgrading of its major production machines.

"We moved into our present dedicated facility last year", explains JDR's Development Engineer, Nigel Wyborn, "and have upgraded our extrusion lines, our 40-carrier and 24-carrier machines and our armourer line.

The result overall has been a doubling of our production capability; we can now make umbilicals up to 10km long! We've used Control Techniques drives throughout and, with the latest upgrade, the armourer, have used the drives' digital communications capabilities to the limit".

JDR's Littleport factory has been set up to manufacture umbilicals up to 10km in length and up to 50t gross weight for the oil, diving and geophysical exploration markets.

The company's relationship with Control Techniques started with the upgrade of two plastic extruders.

"We used both Mentor (DC drives) and Unidrives (AC drives)", explains Nigel Wyborn, using RS485 communications to a PC with SCADA control of the machines.

But with the armourer, we have moved to distributed control, with the software residing on plug-in modules on the drives themselves, CT-Net communications and touch-screen controls.

Apart from the e-stop and local jog stations, there isn't a knob or a button on the whole machine!".

This has eliminated the need for a PLC, with all of the programming being carried out locally on each drive's plug-in processor module.

CT-Net is Control Techniques' own high-speed network protocol, giving decentralised 'peer-to-peer' communications between each drive, various sensors and limit switches, Beckhoff I/O and the main and auxiliary touch-screen control panels.

The 'armouring' machine provides either single or double helical wire armouring to provide damage protection from ships' anchors or rock abrasion or to provide high tensile strength, depending on design.

It comprises a rear deck with wire carriers and a tape head, a main carriage with further wire carriers, another tape head, a capstan and, finally, a take-up unit to wind off the finished umbilical.

The machine is capable of running at up to 22m/min, with a carriage rotation of up to 30rev/min and produces umbilicals with a completed size of up to 220mm.

The fully loaded main carriage has a weight of up to 165t, yet the machine can be stopped in just 4.5s in an emergency.

The machine has been substantially rebuilt at a cost of GBP 500,000, re-using, where possible, existing motors, but the drive system has been totally replaced.

The rear deck is driven by 42kW existing DC motor controlled by a Mentor II DC drive fitted with an MD 29 coprocessor module.

The first tape head is under the control of a 7.5kW Unidrive, the 165t main carrriage has a 171kW Mentor II and the second tape head is controlled by a 7.5kW Unidrive.

The Capstan drive is a 56kW Mentor and this acts as the 'master' reference and the take-up unit has a 15kW mentor and a 2.2kW Unidrive controls the transverse motion for reeling the umbilical.

All of the DC drives are four-quadrant operation, regenerating in deceleration and are fitted with an MD29AN coprocessor to provide CT-Net connectivity.

Similarly, the Unidrives are fitted with UD75 CT-Net modules and UD51 cards for second encoder input signals.

Control Techniques also supplied additional I/O handling with a Beckhoff I/O unit and a field controller to provide constant kilowatt characteristic on the main carriage.

All drives are speed locked, with a better than 0.5% speed variation.

All of the required processing of data, the ratios, the wire counting (a very high-speed input from a laser sensor), the various permissions to run etc are carried out in the coprocessors fitted on the drives, eliminating the need for a controlling PC or PLC.

"The operator simply chooses the run direction, sets the number of wires, the pitch and other parameters shown on the screen and off it goes", says Nigel Wyborn.

"It is very much better than a mechanical alternative which can only make adjustments in fixed increments.

Our machine gives continuous adjustments as small as 1mm.

Equally, the amount of overlap on the (Kevlar) binder can be adjusted exactly as required by the customers' specification.

The Control Techniques product is brilliant - and the service is excellent too.

Any problems during development have been quickly sorted".

Why Control Techniques? "Both Mentor and Unidrive work straight out of the box", explains Nigel Wyborn.

"They have all of the features we need as standard - closed loop control, plenty of I/O for most applications, various internal control blocks such as PID and, using the MD or UD modules, there's really little they can't do.

And we've found CT-Net to be totally reliable too".

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