Shaft encoder

t",RI!!¢II Shaft encoder Capable of slewing speeds up to 5000 rev/min and monitoring + 2.5 arc-sec accuracy, the Disc-Rotaswitch Heavy Duty Series 700 optical shaft encoder is designed for machine shop and similar industrial applications. The encoders have ABEC Class 5 (or better) sealed bearings and can resist axial loads up to 18.144 kg (40 Ib) and radial loads up to 15.876kg (35 Ib). The encoder gives up to 2540 pulse rate output, will operate in 0-70°C and will withstand 98% relative humidity and shock .of 50g. Options with single square wave, dual square wave, and count/no count pulse outputs are available. Disc Instruments, 102 East Baker Street, Costa Mesa, California 92626, USA, or Computer Controls Ltd, 19 Buckingham Street, London WC2N 6EQ, UK

ion

beam processes

For most materials individual laboratory investigations are needed to establish optimum conditions for ion beam machinery, polishing or etching. Ion Tech have recently introduced a Model B362 Ion Beam Microworkshop which they claim enables precise conditions for;ion beam processing to be obtained economically and allows scaling up to pilot or full product processing easily. The Microworkshops incorporate saddle-field ion sources which produce beams of ions and neutrals. Inert gases, such as argon and reactive gases can be used, enabling investigations of both physical and chemical etching techniques. All vacuum compatible materials can be etched with saddle-field ion sources without restriction as to whether the materials are insulating or electrically conducting as the specimens are situated in a field free space. In process optimisation studies, the angle of ion beam incidence, which can be critical, and specimen rotation and longitudinal movement should be investigated to eliminate ion beam produced artifacts. Additionally, ion beam current density must be examined experimentally to ascertain the maximum ion beam power permissible to avoid heating damage to sensitive materials. Ion Tech Ltd., 2 Park Street, Teddington, Middlesex TWl 1 0LT, UK /

168

This is the Mitsui Seiki Machining Centre HP4 with the Okipath 600 control system. Developed from jig borer technology, the Mitsui 32-tool A TC machining centres are made from closed box mechanite castings. A l l three axes attain maximum rapid traverse of lOm/min in O. ls (acceleration and deceleration) and spindle deflection, measured by a customer during recent machining trials, was 1~7t~n (O.O005in) compared with readings of 10t.6t~m (0. O04in) and 203.2 pm (O.O08in) measured under the same conditions by the same engineers on competitive machines. Mitsui Seiki, Kogyo Company Ltd, 3 - 3 Nihonbashi-Muromachi, Chuo-ku, Tokyo, or Soag Machinery Ltd, Transport Avenue Industrial Estate, Great West Road, Brentford. Middlesex TW8 9HB, UK

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custom engineered to give the correct gripping forc for each application and function on the principle of expanding or compressing metals within their elastic limits. Federal Ayreid, Brick Knoll Park, Ashley Road, St. Albans, Hertfordshire AL 1 5PL, UK

PRECISION ENGINEERING