Wahli 90 Gear-cutting Machine. Operating Manual WAHLI 90 Gear-cutting Machine. A two-part Manual: 1) For Sarting up, Setting and maintenance and 2) a detailed Operator's Instruction and Maintenance Manual with an Electrical Schematic and a number of useful Sectional Drawings. Manufacturers: Wahli Models: 90 Contents: Operators Manual Maintenance Manual Electrical Diagrams