PRODUCTION FACILITIES FOR MULTI-TURN METAL-FILM TRIMMER RESISTORS PER SIGNAL CORPS TECHNICAL REQUIREMENTS SCS-127 AND MIL-R-22097B (MODIFIED).
Quarterly progress rept. no. 10, 1 Oct-31 Dec 64,
WESTON INSTRUMENTS INC NEWARK N J
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Preproduction potentiometers of 200 ohms, 1K ohms, 25K ohms, 50K ohms and 200K ohms were tested. Molded insulator parts made from either Fibrite no. 8492 or Mitchell-Rand no. 7034 were found to be most satisfactory in the potentiometer assemblies. A 12-cavity mold has been built for limited processing of these parts in the house. New toroid contact springs with a new satisfactory cross section area have been received and installed in a limited number of potnetiometers. New 302 stainless steel clutch idle springs were received and a quantity of potentiometers were assembled using these springs. Preliminary results indicate the stainless steel springs to have excessive compression for toroid potentiometer operation by preventing in a percentage of cases the contact spring carrier from fully disengaging the drive screw causing the contact spring to revolve within the assembly near the clutch position giving rise to possible excessive wear of the resistive element in this position.