27 January 2016
When deep hole drilling specialist Mollart Engineering Group was looking to replace a 20 year old surface grinder, it turned to RK International Machine Tools, which supplied a Perfect PFG50-150 AHR column-type, PLC controlled, surface grinder that is meeting all of Mollart’s requirements… and more.
Mollart’s business is spread over three divisions, which are the manufacture of new deep-hole drilling machines, tooling and sub-contract machining. The new grinder had to be capable of covering components from across all of these areas of operation. In addition, the company is also expanding its apprentice training, so the machine would also be used as part of the training regime for its future engineers, so ease of use, as well as versatility were key in selecting the right machine. The result is that the machine is located in what Mollart describes as its apprentice section within its sub-contract division. However, this is a fully functioning production environment, where two skilled operators and two apprentices make use of the machine for a variety of tasks, from single, large components, through to multiple loaded parts.
Part of the versatility of the machine had to be its size, in the case of the Perfect PFG50-150 AHR, it comes with a 500 by 1500 mm maximum table and grinding size and a table weight capacity of 1200 kg, which is sufficient for all of Mollart’s internal needs, including grinding of large tailstock castings, machine beds for its own machines, which are fine ground on the Perfect before final fitting. Here the 600 mm distance between table and spindle centreline was an important factor as well as the table length. “So far we have not found a job that the Perfect can’t do and the capacity that it brings has also allowed us to expand our sub-contract service as availability of a machine of this size is not that common,” says Carl Musticone, Mollart’s Plant Manager.
To enhance the accuracy of the Perfect PFG50-150 AHR Mollart opted for the optional one micron linear scales and an Acu-Rite 200S digital readout in addition to the standard plc control unit. This gives added control over positioning in the z and y axes of the machine and in combination with the machine design, where the head moves, rather than the table, Mollart is seeing much better surface finishes when compared to its previous grinder. “The combination of the relative simplicity of the original plc controller and the Acu-Rite readout makes this one of the easiest machines in the factory to operate. Not only that but the support that we have had from RK International can’t be faulted. Our location is not the easiest in terms of machine installations, but it all went without a hitch,” says Carl Musticone.
The Perfect AHR series of machines feature automatic cross feed and the variable longitudinal feed is controlled by a proportional hydraulic valve system that allows the feed to be fine-tuned for specific workpieces. Vertical feed can be controlled using the standard MPG handwheel, allowing the close monitoring of the wheel position wherever it is located along the length of the table. The range also benefits from a number of design features that enhance grind quality including the heavy-duty cast base, in the case of the PFG50-150 AHR giving a machine weight of 7200 kg, the spindle is assembled using P4 grade precision angular contact bearings ensuring runout of less than two micron, while the cartridge design is sealed and lubricated to provide for an extended working life.
“The AHR series of column-type surface grinders is part of an extended range of surface grinding products from Perfect. At the smaller end are the saddle-type grinders, with cantilever and double-column variants sitting at the larger end of the range, with table sizes up to 1600 by 6000 mm. With a choice of control systems therefore, there is a surface grinder to suit virtually any application,” says Dick Aldrich, Sales Director, RK International Machine Tools.
For more information on the PERFECT PFG50-150 AHR please click here. To view the range of PERFECT Surface Grinders with machines for 150 x 450mm to upto 6000mm, please click here or email sales@rk-int.com for more information.
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