squaredrive

Squaredrive is a term used in mechanical engineering and robotics to describe a drive arrangement in which rotational motion is converted to linear displacement through a square-profile drive element and a matching guide or track. The concept emphasizes the use of square cross-sections to constrain motion and to provide repeatable seating and angular alignment. In practice, squaredrive systems can be implemented in several ways, including direct square-to-linear interfaces (such as a square drive pin engaging a matching groove) and more elaborate assemblies using square shafts with guides and linear bearings. They are sometimes described in patents and vendor literature as providing high torsional rigidity and straightforward manufacturing.

In typical designs, a drive motor or actuator supplies rotational motion to a square drive element. A mating slot, groove, or follower converts this rotation into linear travel of a slider or carriage. To prevent rotation of the moving part, a flat or corner square engagement can be combined with anti-rotation features such as bushings, keys, or set screws. Square-drive arrangements can be paired with rack-and-pinion, cam, or scotch-yoke converters to achieve different motion profiles and stroke lengths.

Applications include CNC tooling, precision positioning stages, robotics actuators, and camera or telescope focus mechanisms, where rigid alignment and repeatable step sizes are valuable. Advantages commonly cited are high stiffness, simple cross-section interfaces, and predictable backlash. Limitations include wear on square mating surfaces, sensitivity to misalignment, and limited off-axis motion.

See also: lead screw, rack and pinion, cam, square drive socket.