CNC machine performs variable radius bending

Although the company made its name in tube manipulation, and is a successful business that has been part of Metalrax Group for the past 30 years, Toolspec's managing director, Dick Corking, says it is probably more accurately defined as 'a producer of welded assemblies'. An example of this approach is the tube components for LH and RH versions of a tractor cab grab handle that are being produced on the sixth tube bending machine to be supplied by BLM Group.

Because both conventional and variable radius bending can be combined in the same automatic cycle, the BLM Dynamic 2 is particularly suited to producing the complex components often to be found in the design and manufacture of, for example, furniture, air conditioning systems, motor vehicles and 'yellow goods', such as tractors, excavators and earthmoving equipment.

However, when manipulating tube for these demanding applications the bending process should, ideally, produce a consistently accurate result if, as is the case at Toolspec, each tube component is subsequently placed in a fixture and lugs, brackets, plates and similar items robot welded in place.

Since manual intervention to correct any misalignment that may have occurred during tube manipulation is not an option, there is no room for error, especially when the component in question is a grab handle that locates directly onto glass and cannot be adjusted to fit when delivered to the assembly line.

'The fact that we robot weld the grab handle assembly combined with the actual configuration of the tee-piece demands that we bend the tube within a 2mm envelope, which for tube work is a very tight tolerance,' said Corking.

'We got the initial order before we bought this latest BLM machine on the basis of our track record for this type of work, and I am delighted to report that, over the past 18 months, we have maintained a consistent high quality and order quantities for this particular assembly are expected to double in 2007.' Toolspec produces a wide range of bent tubular products, from brake pipe assemblies to safety cages for earthmoving equipment, and is a long-established user of BLM Group equipment.

The tractor cab grab handle order has been placed by a French OEM and it is not the first time that Toolspec, with the help of BLM's applications team, has replaced an overseas supplier.

'To succeed against stiff European competition demands investment in modern production equipment and the Dynamic 2 has risen to the challenge of a difficult component and a high standard of accuracy and repeatability,' said Corking.

'Although the component features a multiple-radius bend it looks as though it is a single, gentle radius.

Even so, BLM Group was the only supplier prepared to guarantee that its machine would do the job - in a cycle time of around 45 seconds - and an added bonus is that the after-sales support is very good.' The Dynamic 2, which can bend tube up to 42mm diameter, can be equipped with up to two sets of bend tooling for conventional bending with two different radii, or compound bending with little or no straight between the bends.

This, combined with the capability of producing variable radius bends and curves along the entire tube length, makes it a totally flexible tube manipulation system.

The Siemens 840Di CNC fitted as standard to the Dynamic 2 uses digital technology and the graphical interface can be personalised to user requirements.

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