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Precision Flatness Gauges .Monochromatic Light UnitOptical Flats .Polishing Stand .Hand Lapping/Polishing Plates

Precision FlatnessGauges

All Lapmaster precision flat lapping machines are of the “ring lapping” type.This design permits high standards of flatness to be routinely achieved by careful adjustment of the lateral position of the cast iron conditioning rings on the annular lap plate track.To consistently achieve successfulresults it is essential to periodically assess the flatness of the lap plate. As well as giving a spot check at the time of testing, the results of a series of checks, if recorded, will form a log and allow analysis of trends, providing information for correctional measures to be made if required ie: adjustment of the conditioning ring positions.There are several methods of testing,for example a monochromatic light and optical flat can be used to set up an interference pattern.This technique requires that the surface to be tested is reasonably reflective, so in most cases after lapping and cleaning, a hand polishing operation must be carried out.This check can be carried out on the component itself, or on a special test plug made of brass, which can run along with a batch of parts.Full details of this technique can befound by referring to the Bulletin “Measuring Flatness with Lapmaster Monochromatic Lights and Optical Flats”.(Copies available on request.)The benefit of the Lapmaster flatnessgauge is that it allows direct reading of the flatness of the lap plate itself once it has been cleaned.It also eliminates the need for a hand polishing stage, which is particularly beneficial when large components are being processed. The gauge is of the spherometer typehaving a dial test indicator mounted in the centre of a cast iron body. The gauge rests on three feet, which are fitted with hardened steel ball anvils.(These are screwed in and can be replaced should they wear after prolonged usage.)A choice of metric or Imperial versionsis offered, with resolutions of 2 microns and 0.0001”respectively.This means that the resolution of the flatness gauge with interpolation is 1 micron over 237mm or 0.00005”over 9.33” (equivalent to one sodium light band over 71mm/2.8”).The gauge is zeroedprior to use by setting it on a master flat so that all three feet and the anvil of the dial gauge are on the same plane, and the dial test indicator bezel or the adjustable foot are then adjusted to set the indicator to zero.Each gauge comes complete with a hardened steel master flat, lapped and polished to a flatness better than 0.3 micron/0.000012”, and a sturdy wooden box which houses both when not in use. Two sizes of gauge are available asfollows:
ACCESSORIES Nominal 5”Metric version X91000006Nominal 5”Imperial version X91000102 This size is suitable for use with Model 15 bench mounted machines. Nominal 9”Metric version X91000003 Nominal 9”Imperial version X91000103 This size is suitable for use with the Model 24, 36, 48, and 56.