Most cable drive systems use a strong steel cable – aircraft cable is the norm. The main disadvantage of this Passenger Lifts type of drive system is that the ride can be less than perfectly smooth. However, technology has moved on and those companies that still use this drive system say that the ride is as smooth as any other type. Summit and Ameriglide stair lifts both use this drive type.
Chain drive systems are used only for heavy duty models. They are loud and not really used in residential stair lifts.
The screw drive uses a lifting mechanism with a screw driven actuator. This is powered by a rechargeable battery. Again, this type is not used in home models.
The rack and pinion drive system is by far the most popular type for residential stair lifts. Rack and pinion systems – meaning gear and teeth – used to have to require regular cleaning and replacement of gear oil. However today’s home units have sealed drive systems that require no maintenance at all.
The Track or Rail
This is the base along which the carriage travels. The track is always fitted to the stairs and never to the wall. This means that a track can be fitted to either side of the stairs. Tracks used in straight stair lifts are made of extruded aluminum whereas curved ones usually use a mixture of both steel and aluminum.
With early designs the power source was AC mains. But today, most stair chair lifts are powered by DC 12 volt rechargeable batteries. Batteries are preferred because a trailing cable is used with AC mains powered stairlifts. The cable is reeled out and reeled back in each and every time the chair travels up and down the stairway, which causes wear and tear. Also, battery powered units can still be used during power outages. Some states prohibit the installation of any appliance unless it is installed by a qualified technician.