Indexer gives precision subcontractor 4th-axis capability
PGC Precision Engineering Ltd, based in Cheltenham, has recently invested in a Hardinge 16C high-performance rotary index system. The company has experienced an improved 4-axis machining capability and the rotary indexer ‘is in constant use…everyday’, according to managing director Mark Hall.
PGC’s specified the 16C rotary indexer at the same time as the investment in a new Bridgeport 650BP3 Vertical Machining Centre and is a permanent and integrated ‘hard-wired’ feature of the new machine.
PGC manufactures a range of complex high-precision parts and components for a diverse range of industries and sectors from a variety of materials including aluminium, stainless and inconel, and are typically between 10 and 200mm and are machined to tolerances of 10microns or less and high surface finishes of Ra 4µm.
Hall states: ‘Owing to the nature of the work we do, our 16C rotary indexer’s performance is critical. Accuracy and repeatability can never be compromised and reliability is also crucial because the indexer is in constant use.’ Hardinge’s 16C indexers feature robust dual-bearing spindles that can accommodate higher radial and axial loads, which greatly increase their application use and potential. They are equipped with steel worm gears, with cross-axis helical gears and ground steel worm drive shafts, that reduce the effects of backlash and deliver improved accuracy (+/- 15 arc second); give better repeatability (6 arc second) and ensure maximum run-out accuracy of 0.005mm. They also dramatically help to reduce tool wear.
For reduced cycle times and increased productivity the 16C rotary indexers have an indexing speed of 0.001 to 300 degrees-per-second. The Collet-ready spindle nose is said to allow for quick and easy job changeovers.
Hall continues: ‘The 16C indexer has made us more competitive. For a large proportion of the parts we manufacture the first operations are performed on our CNC lathes and subsequent operations of milling, drilling, tapping and contouring are undertaken on the Bridgeport machine using the indexer.
‘By having dedicated 4th-axis capability we can reduce job set-up times and increase part accuracies at the same time.
To get the most from the indexer, the company has invested heavily in associated workholding products and equipment. These have included a 5C spindle adaptor, collets, step chucks, expanding collets, tailstock, 3-Jaw chucks and to manufacture thin-walled parts and components with delicate and intricate features, the company has invested in soft-jaw chucks.
Hall concludes: ‘Our 16C rotary indexer is vital to our future growth and success. It has helped us reduce lead times and has made us more competitive. It has also allowed us to be more creative in manufacturing our own bespoke, high-productivity workholding jigs and fixtures for machining multiple workpieces in just one set-up.’
