German vertical machining centre manufacturer Roeders, whose machines are sold into the UK and Irish markets exclusively by Hurco Europe, is rolling out a new range of milling platforms. The machine feature optional integral grinding capability that can achieve extraordinarily tight workpiece tolerances.
The RPT series of three- and three-axis VMCs is said to achieve tolerances half those obtainable using Roeders’ established RXP machines. Roeders’ latest VMCs can remain geometrically stable to within ±1 µm, even if the ambient temperature fluctuates as much as 3°C.
Achieving this level of precision would normally require housing the machine tool in an air conditioned environment. Roeders concentrated instead on holistic temperature management within the machine, integrating PreciTemp technology to achieve a high level of consistency and repeatability.
Customers can specify three increasingly sophisticated levels of temperature compensation and sensor feedback to the CNC, according to requirements. It can involve a combination of some or all of the following cooling measures: temperature control of the machine table and rotary axis bearings; temperature control of the torque motors in the trunnion-type five-axis machines; and temperature control of the air in the working area, surrounding the axis drives and in upper part of the machine guarding.
Thermal stability of the portal structure and machine bed is maintained by embedded pipework carrying chilled water. There is similar circuitry for the spindle and its surrounding sleeve to prevent growth in the Z axis, which is monitored to sub-micron accuracy by an external, non-contact sensor. Software algorithms derived in the course of machine development compensate for any remaining minimal residual errors.
More information www.hurco.co.uk
