Taking a shine to grinding

Having secured a long term contract to finish machine chromium plated hinge pins used in aircraft landing systems, Bristol-based Redcliffe Precision has invested in a new Jones & Shipman Suprema 650 EASY U cylindrical grinding machine to fulfil the contract. The purchase of the machine brings in-house a process that has proved challenging for even highly specialist grinding shops who have struggled to meet both the demanding tolerances and the productivity necessary to make the operation cost effective. “Grinding hard chrome workpieces is widely accepted as being a challenge,” explains Redcliffe Precision CEO and managing director Kevin Sage. “The pins are a ‘wear' part and the hard chroming is necessary to offset both wear and harsh operating conditions. That said, the hard chroming process creates an inconsistent component to grind and one in which creating too much heat (by grinding) can result in costly rejects. We consulted with Jones & Shipman about our dilemma and after conducting some rigorous test projects, they advised investing in the Suprema machine and bringing the process in-house.”  <Less of a grind> After chroming the pins have a coating of about 0.006” with the grinding operation reducing this by half. Grinding time per component has been significantly reduced to around and hour in comparison with previous 2-3 hours on manual machines. “Repeatability is also all important,” Gage explains. “Our machine is supplied with a Fanuc touchscreen control and J&S EASY grinding and dressing software which our operators have found very straight forward to adapt to.” The latest Suprema machine range is the J&S ‘all-rounder' being suited to highly demanding applications from one-offs to precision small batch work or full production applications. With its Fanuc touchscreen control and J&S EASY grinding and dressing software, the Suprema 650U offers linked cycles, automatic in-cycle dressing and full dress compensation for quick and easy set-ups. Flexibility is assured via the universal wheel head configuration of left and right external and internal wheels with airlift and automated clamping. This variant also offers an optional manual ‘B' axis wheelhead which has a 0.001° readout integrated into the Fanuc control system and J&S EASY software. There is also a dedicated straight approach external only wheel head variant available on all Suprema models. Redcliffe Precision has been supplying precision components to the aerospace industry for over 30 years, specialising in all aspects of grinding, milling and turning and precision thread rolling and thread testing for cracks and deviations. Founded in 1968, Redcliffe Precision built its reputation manufacturing aerospace components for Spares, AOGs and Fast Track. www.jonesshipman.com