Ring encoders provide high accuracy feedback of angular motion

The ECA variant offers 60% smaller position error and 45% faster operation. Typical applications are controlling the position of swivelling heads, spindles and rotary tables on tool and gear grinders, machining centres and CNC lathes. The units may also be used to control robots and to position semiconductor wafer motion stages. Owing to the ECA 4000’s wide mounting tolerances, it is easy and quick to assemble to the host equipment.

Each ring employs a three-point method that allows the installer to align the centres of the encoder drum and machine bearing in just a couple of minutes. After setting the scanning gap between the read head and the Outside Diameter (OD) of the steel drum, signal quality is verified and the encoder system is ready for feedback to the control via a Heidenhain Endat 2.2 high-speed serial interface. Scanning units with Fanuc α / αi and Mitsubishi serial interfaces may alternatively be supplied.

ECA 4000 encoders are available with a wide spread of drum ODs from 104 to 560mm. Inside diameters range from 70 to 512mm so that machine designers can pass cabling and other services through the centre to streamline machine design. Each ring size has a unique line count around the outside, up to 44,000 in the case of the largest model, for which an accuracy of ± 1.5 arc seconds is specified for the twin-track graduations.

Each ring is capable of resolutions better than 0.01 arc second. Fast reaction time, even at speeds up to 2,500rpm, make the encoders suitable for use with direct drive motors. The encoders have a high degree of vibration and shock resistance, a protection rating up to IP67 and an operating temperature range of -10 to +70°C.