German-built whirling machines from the company form the foundation for soft cutting at finish tolerances. These high speed, high precision machines produce parts to AGMA Grade 6 specifications, with lead, pitch and profile tolerances of less than 0.0005"--performances that challenge precision grinders, but that are routine in a single pass when produced by whirling.
In whirling, the cutter arrays from four to 24 carbide inserts along the inside circumference of a cutting ring. The ring is then positioned to produce the desired pitch and angle and rotated about the workpiece at speeds to 1,000 rpm with feeds of 200 to 750 sfm. Whirling produces worms in a fraction of the time required by grinding, the company says.
Because whirling does not require undercuts at the ends of the worm area, the worm face width can be optimized and the overall shaft length reduced, according to the company. This is said to make a more rigid, more compact and stronger design. Eliminating undercuts is also said to eliminate the need for deburring tooth ends.
The company has added automated axis adjustments and a quick-change collet system. Setups are now completed in less than 15 minutes.