Non-slip tachometer roller

摘要

A method of forming a tachometer roller for a tape drive assembly for detecting the speed of a tape moving along a reference axis when the tape is in contact with the roller. The roller includes a cylinder extending in a longitudinal axis and adapted to be fixed in a tape drive assembly for rotation along the reference axis. The periphery of the cylinder defines an air vent groove running obliquely to the longitudinal axis for venting of air captured between the periphery and the tape. The vent groove terminates in respective circumferential grooves formed in respective edge portions of the roller. The vent groove is formed from a single plunge cut of a tool starting at a first circumferential groove and terminating at the other circumferential groove.