Gear Technology Magazine
www.geartechnology.com/articles/23049

DSM’s Stanyl Precison Gears Help Disabled Patients Drive Independently

April 11, 2006
Precision gears made out of Stanyl, a high-performance polyamide 46 (PA46) resin from DSM Engineering Plastics, help keeps the Joyster moving. The Joyster, demonstrated at Hannover Messe 2006, is a new joystick-like system designed to enable drivers with arm muscle disabilities to drive by themselves. Developed at the Bern University for Applied Sciences HTI-Biel, the new product augments a car’s conventional steering wheel with a pair of joysticks mounted on either side of the wheel. These are electronically coupled to the vehicle’s steering mechanism. The Stanyl gears were fabricated by Mikron Plastics Technologies and are utilized at the joystick and the vehicle’s steering shaft. The joystick gears must precisely translate small movements to programmable encoder circuitry. The movement required is small, and the touch must remain light. The steering shaft gears, on the other hand, must apply strong forces to the vehicle’s steering system. A critical aspect of the design is feedback to the driver. Small motors in the joystick mechanism provide resistance that is sent back to the driver through the joystick gears. This resistance signals the severity of the turn and transmits the road feel of bumps and surfaces to the driver. This enables the system to give drivers the same kinds of tactile information a driver would sense while using a conventional steering wheel. The degree of feedback can be programmed for a given driver’s muscle capabilities.