As a subcontract manufacturer serving the automotive, medical, nuclear and agricultural sectors, Scot Bennett Engineering Ltd has just invested in a Star SR-32J sliding head turning centre. The new addition is the fourth sliding head turning centre from Star.

The company that initially bought two 20mm diameter capacity Star machines has since added to the Star plant list with the third and fourth machines both being 32mm capacity for the machining of larger components. The fourth machine, a new SR-32J was delivered just before Christmas and the commissioning and staff training was conducted at the start of the New Year.

Referring to why the Kingsthorpe Company invested in the SR-32J, the Managing Director at Scot Bennett Engineering Ltd, Mr Rob Bennett says: “We’ve always invested in equipment that will give us extra capacity on material and engineering capabilities. The 32mm machine we bought this time was installed with an extended guide-bush collet unit that allows us to machine stock bars of 35mm. We also specified high pressure coolant that allows us to work with difficult materials that cause swarf and chip problems, as well as deep hole drilling issues.

“We are already using bars up to the 35mm capacity of the machine and the high-pressure coolant is being put into practice on softer materials that tend to be sticky. These materials have historically caused the swarf to wrap around the tools and drills. By breaking the swarf and evacuating it from the work envelope, we can run extended production volumes hassle free.”

In fact, one of the primary reasons behind the purchase was the arrival of an EN3B steel job. Often difficult to machine, Scot Bennett has had issues with the breaking of swarf and the consequent evacuation. The small component that required external turning, grooving and internal drilling and threading was suffering from sub-standard surface finishes created by the swarf removal issue. The high-pressure coolant on the new SR-32J has completely eradicated this issue and is giving the ISO: 9001 accredited subcontractor surface finish values that meet the precision, quality and aesthetic demands of the business.

With a regular volume requirement from 1000 to 2000 off, the EN3B parts were previously machined on a fixed head machine in two operations. This would consist of front-end machining with the secondary operation consisting of a machine operator manually deburring the back-end of the parts and checking the quality of the threads.

With both front and back-end working, the 7-axis Star SR-32J has over 26 tool positions for the simple set-up and machining of all material types and batch quantities that the Northamptonshire business produces. Regarding the configuration and running of the Star SR-32J, Mr Bennett continues: “It’s a common misconception that sliding head machines are only suitable for long production runs. In the old days of CAM type machines, it would take a setter 6-10 hours to set-up the machine. Nowadays, the FANUC control system enables us to set the machine in anything from 1 to 3 hours depending upon the complexity of the job. We recently ran a small batch of just 100 parts on the machine.”

Going back to the EN3B part, Mr Bennett is confident that the proximity of the cutting tools to the workpiece and the elimination of secondary operations will drastically reduce the cycle time for the regularly running job. Concluding on the purchase of the Star sliding head machines, Mr Bennett says: “Whenever I have called Star whether it’s for sales advice or service; and it sounds like a cliché, but I have felt like their only customer because the service is so good.”