Retouching projector

eU¢| Contour measuring unit Contour measurements of both sides of a bore, the underface of a component or a similar pair of laterally opposed faces are the advantage of a contour measuring head, the PM2-SF, developed by Hommelwerke. To achieve the double measurement, the instrument is fitted with two stylus tips of 20 #m radius, one pointing down and the other up. To make a conventional surface measurement, the finely balanced arm operates under gravity. The fine balance of the arm ensures that while the downward stylus sensitivity tracks across the surface it exerts just sufficient force to remain in contact with the surface. To measure accurately a laterally opposed face with respect to the first, the arm is magnetically biased upwards and uses the second stylus. The instrument is fitted with a sensitive vibrator control which when applied to the stylus enables the measuring arm to ride up vertically machined faces. Vertical magnifications of up to 1000X, and horizontal magnifications of up to 100X are possible with the system. Hommelwerke GmbH, D-7730 BS-Schwenningen, Stadtbezirk MLihlhausen, FRG or Optical and Mechanical Development Company Ltd, Fircroft Way, Edenbridge, Kent, UK

Go/no-go ball gauges Use of a ball section for the go and no
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extremely close tolerances, they are not prone to jam or bind in the hole as is frequently the case with conventional cylinder gauges. The hole can be measured without any need to line up the plug gauge exactly on the centre line, an important feature. With their high standards of sphericity, these new gauges from Spheric Engineering Ltd will in fact enter even when presented at quite a wide angle to the hole, making the job much easier for the operator, particularly in confined spaces where exact visual location may be difficult or impossible, or when measuring on an internal grinder. As a ball gauge measures only with a single precise radius, rather than the extended length of a cylinder gauge, it is much more sensitive in 'feel'. This makes it more effective in detecting and assessingtaper, bellmouth or roughness in a bore. Spheric Engineering can supply their ball-ended precision tungsten carbide plug gauges to the ISO standard, or to any specified requirement up to a diameter tolerance of plus or minus 0.000 01 in (0.25/Lm). Spheric Engineering Ltd, Fleming Way, Manor Royal, West Sussex, UK, RH10 2SQ

Retouching projector Designed primarily for the checking and retouching of films, printed-circuit boards and through plating, the RP 400 retouching projector from Finlay Microvis~on is also suitable for checking of etching deficiencies and short-circuits, for examination of inprinted leads, solder eyes, the displacement of holes, displacement of solder, lacquer-masks and of solder-stop lacquer etc, and for the detection and examination of cracks, undercutting and scratches. The RP 400 provides a laterally correct, true colour image that is the same on the projector as it is through the stereo microscope. The instrument permits operation from an ergonomic working distance of 113 mm. Formats of 500 mm x 600 mm or larger, are available. With the ball bearing mounted printed-circuit stage, a range of 400 mm in the X direction and 300 mm

in the Y direction can be scanned. The usual method of checking is to scan continuously in the X direction with fixed steps at the end of each scan in the Y direction. The Y step is fixed at such a distance that the image on the screen overlaps the previous scan slightly so that the test object is scanned without gaps. The screen with Fresnel lens (on request with mm scale) measures 175 mm x 175 mm. The optics are set with magnification changer, focussing objectives and projectives; all three magnifications are parafocal. Surface illumination is by means of a 24 V/ 250 W quartz-iodine lamp. Finlay Microvision Co Ltd, Pendicke Street, Southam, Leamington Spa, Warwickshire, UK

Tooling resins Ciba-Geigy have produced a comprehensive range of new literature on their recently launched Ureol tooling resins, and revised Araldite tooling resin range. The range of Ureol polyurethane resins and Araldite epoxy resins available is detailed and illustrated examples of how these resins may be used in press tools, vacuum forming tools, jigs and fixtures, die aids, core boxes, master models and patterns are included. A workshop chart of the revised Araldite tooling resins, detailing the systems available, the correct mixing ratio, heat deflection temperature, whether they are compatible with aliphatics or aromatics, and other characteristics of the systems, is included. Ciba-Geigy Plastics and Additives Company, Plastics-Division, Duxford, Cambridge, UK, CB2 4QA

Steel roller dressing devices 'Truing and Dressing of Resin Bond Peripheral Wheels' is the title of an eight-page booklet by G. R. Shafto and A. T. Notter. The authors compare the surface textures of grinding wheels prepared by various truing and dressing techniques and evaluate two devices for preparing resin bond wheels by the grinding of mild steel rollers. Reference L49, De Beers Industrial Diamond Division (Pty) Ltd, Charters, Sunninghill, Ascot, Berkshire, UK, SL5 9PX

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