Grinding Automation And More From RK International At MACH 201826-Jan-2018 RK INTERNATIONAL MACHINE TOOLS LTD
Grinding automation and more from
RK International at MACH 2018
RK International Machine Tools will be maximising its presence at MACH 2018 (stand H19-314) with an emphasis on the latest developments within its grinding portfolio in terms of machines on display. The five machines being shown are the Perfect X36 High Precision surface grinder; the Jainnher JHC 12S centreless grinder, the Robbi 600 ET 7 universal cylindrical grinder; the high precision Delta Rotax 7 rotary table, horizontal spindle grinding machine, and the Delta LC400 rotary table surface grinder. In addition to machines on the stand, visitors will also be able to discuss their requirements for a range of machining systems from turning and milling through to thread rolling, EDM and sheetmetal equipment.
The Perfect X36 High Precision surface grinder features a 300 by 600 mm table with maximum distance between the table and spindle centreline of 600 mm. This capacity is backed up by a 7.5 hp (10 hp option) CP4 high-precision spindle, with pre-stressed adjustment and grinding wheel speeds up to 1750 revs/min, with a maximum wheel size of 355 by 50 by 127 mm. The cross and vertical axes make use of linear slideways (box slideway optional on the vertical axis) while for added rigidity the x-axis remains as a box slideway as standard. The Perfect X36 benefits from one-micron programmable resolution thanks to its upgraded ADP PLC control, which is proving popular with more and more grinding shops that are looking for an easy-to-use PLC control to tackle their grinding work. The ADP PLC control allows multiple grinding cycle routines, including surface, criss-cross, plunge, and pitch grinding. And, in addition, the machine can also be operated in full manual control using the standard joystick when required, but these movements are monitored and safeguarded by the PLC control. All of which help to reduce the skill levels required to produce high quality components.
The Jainnher JHC12S centreless grinder can be configured with its servo controlled, variable speed, regulating wheel the machine can be configured with a grinding capacity of 1 to 25 mm diameter as standard or, with the optional workrest, this can be expanded to 25 to 40 mm diameter. The machine on display at MACH will be fitted with an automated load and unloading system, where part loading will be via a hopper, pushing the part through the machine into a receiving tray. For added precision and machine longevity, the Jainnher JHC 12S 7.5 hp spindle features a precision ground, hydrostatic bearing assembly, providing minimal friction, therefore reduced wear, and lateral displacement, along with extended wheel life under heavy grinding loads. Key features of the Jainnher JHC12S include a maximum grinding wheel size of
305 mm x 150 mm (Dia/Width), a 205 by 150 mm regulating wheel, which can be tilted +5 deg – 3 deg and swivelled +/- 5 deg, micro table feed using the handwheel of 0.001 m, with a movement of 0.2 mm for a full rotation of the wheel. All of this is contained in a compact footprint of just
1750 x 1350 x 1400 mm.
For universal grinding applications RK International will be showing the Robbi 600 with the latest generation ET7 control system, which provides an advanced seamless grinding experience that helps to reduce the complexity of part programming, including dressing cycles. With 630 mm distance between centres, this semi-automatic, PLC-based machine provides users with outstanding versatility, allowing economical grinding of batches as small as one-off. Key features include the ability to grind components weighing up to 250 kg (300 kg optional), a maximum table swivel of +9/-5 degrees, workhead rotation of between 0 and 300 revs/min. For larger workpieces Robbi has three larger variants with within the mid-range E Series with 1030, 1530 and 2030 mm between centre distances. The wheelhead contains a hydrodynamic spindle, rotating on anti-friction metal bushes that help to enhance surface finish quality, and its position is controlled to within 0.001mm by use of the incremental motor’s encoder in a closed loop. For additional accuracy an incremental linear encoder can be specified. Alongside the Robbi 600 will be a demonstration of the optional standalone control pendant display featuring the latest SIEMENS 840D sl with Industry 4.0 capability.
The grinding theme continues on the stand with the Delta Rotax 7 a travelling column, rotary table, horizontal spindle grinding machine. As with all three machines in the Rotax series, the Rotax 7 features a stabilised Meehanite cast-iron structure generating maximum rigidity for increased metal removal rates and improved flatness quality. Due to the travelling column design there is no ‘fall-off’ of the wheel across the 700 mm grinding diameter. Accuracy and performance is also enhanced by use of full grip hydrostatic support on all machine axes and wheelhead, eliminating friction, machine wear and stick slip. The spindle motor is a 7.5 kW Mackensen hydrodynamic unit with a Mackensen hydrodynamic bearing on the front and a pair of pre-loaded precision ball bearings on the rear. The rotary table is supported by two pre-loaded high precision ball bearings with 25° contact angle (this changes to a hydrostatic journal on the two larger machines in the series) with drive provided by a torque servomotor, which can be equipped with electro-permanent magnetic chuck. Each machine is available with a choice of three user-friendly (full production with just half a day training) automation levels using Delta developed software on their CN and CN Plus control systems allowing self-diagnostics and un-manned running.
Completing the MACH machine line-up for RK International is the Delta LC400, part of Italy-based Delta’s ELLE range of rotary/fixed/oscillating table, vertical spindle surface grinders. The Delta LC 400rotary table variant is capable of grinding components up to 400 mm diameter and up to 205 mm high (distance between table and grinding wheel). The rotary table of the LC400 is controlled by asynchronous three-phase bipolar motors with 8/16 poles; the result is that table rotation can be as high as 40 revs/min. When combined with the vertical spindle the result is a highly rigid and productive machine capable of high metal removal rates.
“The combination of grinding machines on display is an excellent cross-section of the ranges offered by our world-leading partners. The range and capability on show highlights RK International’s reputation as the UK’s leader in grinding technology, able to meet the needs of customers across a diverse variety of industry sectors. We are confident that MACH will provide the perfect showcase for RK International’s product ranges and technical ability, as such we have backed this up by taking the largest stand in the company’s history at the show,” Simon Rood, Director and General Manager, RK Internmational Machine Tools.