HARTFORD DOUBLE COLUMN VMC HELPS WICHITA OF BEDFORD WITH POWER TRANSMISSION PARTS MACHINING
The introduction by power transmission specialist Wichita of a Hartford HB-2190 double column vertical machining centre is not surprisingly producing better quality workpieces in shorter cycle times that the unreliable 20-year-old machine it has replaced.
Performing a range of predominantly drilling and tapping as well as milling operations on a variety of clutch plate components up to 48 inches diameter the machine, supplied by Ward CNC, has immediately enabled the Bedford-based company to:
Reduce cycle times by taking deeper milling cuts at faster feed rates
Improve workpiece quality (surface finish), and
Boost overall machine utilisation levels by having 30 of its 40-tool ATC permanently set-up for a variety of jobs - compared with the 10-tool machine it replaced - to thus reduce downtime caused by impromptu tool changes.
According to manufacturing systems manger Vince Hughes, the quest to replace an ageing VMC involved a survey of the market and the eventual shortlisting by him and senior production engineer Ian Fielding of four possible machines that met the requirement for a machine having the necessary large bed area of 2,100 mm by 1,740 mm.
"The Hartford was selected on the basis on specification, price and recommendations after site visits to existing Hartford users who gave favourable reports," he says.
"We could see that the machine was of solid construction and felt reassured that Ward would provide a good level of service back-up, too.
With X, Y and Z axis travels of 2,000 mm by 1,970 mm by 920 mm and a 2,200 mm width between columns, plus rapid traverse rates of 10,000 Mm/min in all axes, the HB-2190 has a spindle speed of 40-4,000 revs/min from a 18.5 kW motor and feed rates of 1-5,000 mm/min.
In addition to satisfying Wichita's prerequisite for a substantial working area, the machine also features high-pressure, through-spindle coolant supply "which enables us to use a mix of carbide-tipped tools" to maximum effect.
The machine is programmed offline, and within the first two months of installation had actioned 60 programs for the range of clutch plates, bodies and rings required for the vast range of pneumatic and hydraulic clutches and brakes, tension control systems and ancillary products designed and manufactured for a global customer base in industrial, mining and marine applications.
Sited in the company's large machine cell, the machine processes a wide variety of mostly cast iron workpieces in small batches, which are first turned and /or gear cut before being placed on the Hartford for finish machining - always more drilling and tapping than milling. Components leave the Hartford finish-machined and ready for on-site assembly.