BELL & HOWELL - bh camera design 70

Comprehensive service manual for Bell & Howell Design 70 16mm film cameras, covering models DA, DL, H, DR, and HR. This detailed technical document provides two primary sections: a complete service guide and an exhaustive replacement parts catalog. The service section begins with an introduction featuring model identification by code letter, a complete listing of specialized tools required for repairs, and comprehensive disassembly procedures for each major assembly: winding key mechanism, hand crank assembly, camera cover assembly, front plate, rear mechanism, and camera frame. Specific instructions address cleaning, inspection, and repair procedures. The reassembly section details systematic reconstruction of all components with critical steps covering main drive spring, governor gears, speed adjustments, sprocket synchronization, aperture adjustment, and buck tooth gear alignment. The manual includes final test procedures encompassing film test, light-leak test, and general operational validation. The parts catalog illustrates and inventories all removable components with part numbers, units per assembly, and usability codes by model. Detailed exploded-view diagrams facilitate precise component identification. Special notes alert technicians to critical differences in gear pressure angles between camera generations (14-1/2° versus 20°), essential information for proper reassembly and avoiding excessive noise and wear.