CNC machine tools and sheet metal machinery
A Suffolk fabricator has just installed an 8m tandem press brake

Factory Farming

A Suffolk fabricator has just installed an 8m tandem press brake, one of only a few of its kind in the UK. Steed Webzell went along to see

New headquarters on a disused US Air Force base in the Suffolk countryside is the unlikely location for John Harvey Engineering Ltd. That said, this progressive OEM and subcontract fabricator is perfectly at home in its rural surroundings as its chief industry of supply is agriculture, with 90 per cent of its customers based locally in East Anglia. Established in 1980 primarily as a manufacturer of free range outdoor equipment for farm animals, John Harvey Engineering today produces a wide range of livestock shelter and accommodation such as farrowing huts, dry sow huts and service huts (all for pigs), along with ancillary equipment such as wallows, drinker bars and feeders/hoppers. The company also manufactures a range of units for free range poultry farming. All sawing, shearing, profiling, bending, welding and assembly operations take place at the company’s facility on Parham Airfield, Framlingham, Suffolk. With business brisk, John Harvey Engineering was recently encountering a bottleneck on its existing 5m press brake. Also, the company began to secure contracts that required the bending of 6m components. “The addition of extension horns for the bed and ram overcame this difficulty, but at the expense of long set-up times,” explains company founder John Harvey. “And it didn’t solve the bottleneck – we still only had one machine.” Entering the market for a replacement, the company became attracted to the idea of a tandem model, which would not only provide the separate flexibility of two independently controlled machines, but also that of a stand-alone press brake – switching between the two capabilities within a matter of 30 minutes. Having studied a number of potential models, it was a Durma E-40200 synchro hydraulic CNC press brake supplied by UK agent Axe & Status that eventually won the day.

“The Durma is a competitively-priced, high quality machine from an established manufacturer that features widely available spare parts,” states Mr Harvey. “Furthermore, there is a foolproof way of ensuring the two controls are linked correctly for tandem operations before the ‘go’ button is pressed,” he says. “On some machines you don’t find out until you have an 8m piece of scrap steel and a set of twisted tooling.” The company typically uses the machine to bend 2-3mm thick mild steel, although occasionally up to 8mm. Batch sizes are fairly small – usually between 100 and 200-off – hence quick and easy set-up is paramount. “The Durma has halved our set-up times in comparison with our old press brake,” says Mr Harvey, “while our apprehension of taking on 20ft work has been completely eroded.” The Durma E-40200 can be used as two individually controlled 4m, 200T press brakes, or as a stand-alone 8m, 400T machine. It features total ram control, which allows the operator to program very slow pressing and return speeds when manipulating large sheets. This greatly improves handling as the sheet is pushed into the lower die to create the bend. By slowing the pressing speed down to a 'creep' it is possible to virtually eliminate conventional sheet 'whip up'.

Operators can also program the ram to rise very slowly for a short distance after completing a bend, then stop and pause while the operator has a chance to take the sheet back under his control, instead of the ram simply releasing the sheet at the bottom of its stroke and immediately returning to the top. This not only improves material handling but can increase part quality by virtually eliminating 'dishing or bowling' around the bend area. Word is spreading fast about the company’s new centrepiece, with new subcontract orders already arriving from sectors such as waste recycling, construction and highways.

“There can’t be many machines like this in the UK, let alone Suffolk,” says Mr Harvey, “so it’s easy to see why it’s attracting so much interest.”

Article reproduced with kind permission from Engineering Subcontractor- June 2008

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