Accuracy, applications and features of GMT Planetary Lapping Machines

Accuracy:		Planetary Lapping Machine Lap plate with work carriers Optical flat
	One light band to two light band over 75Ø component. (i.e. 0.3µ to 0.6µ over 75mmØ).
	Surface finish : 0.2µ Ra.
	Parallelism : 0.002mm over 75mmØ.
Applications :
These machines can be very sucessfully used in:
	Electronic industries for lapping silicon wafers, germanium wafers, ferrite and piezo electric ceramics.
	Pump industries for lapping mechanical seals made of tungsten carbide and ceramics.
	Air compressor industries for lapping compressor valve plates.
	Automotive industries for lapping thrust washers and distance pieces used in power steering.
Features :
	The machine is constructed on a rigid welded hollow section steel frame, which houses a AC motor offered with variable frequency drive and a worm and worm wheel reduction gear unit.
	The central gear, internal ring gear and work carriers are driven a AC motor.
	The drive from the AC motor is taken through a worm and worm wheel reduction unit and then goes centrally through the main spindle to the central gear to the internal ring gear, through the work carriers.
	The drive from reduction gear unit is through a unidirectional clutch arrangement. This arrangement ensures a smooth motion when the machine is started. This feature also eliminates breakage of fragile components like silicon and germanium wafers while starting and stopping the machine.
	Both the lap plates are stationary. The differential motion given to the work carrier results in a random figure of '8' motion. This ensures that the component comes in contact over the entire area of the lap plate in so far as is feasible in line with the geometry of the component.
	A special camel back straight edge permits rapid and accurate assessment of the flatness of the lap plates.
	A set of special cast iron lapping gears are supplied with the machine for relapping the top and bottom lap plates.
	An independent slurry pump feeds the mixture of abrasive and oil to an abrasive feed assembly.It is then distributed through a spider to the working face by means of strategically located holes. A separate stirrer motor is attached with the pump to continuously stir the abrasive with oil.
	The main spindle bearings are sealed against ingress of the abrasive slurry. The used slurry is carried away by a suitable arrangement and is collected in a removable tank.