The US moving-coil actuator (MCA) specialist SMAC has launched a series of 12mm-diameter actuators which it describes as first linear motors to challenge LVDT (linear variable differential transformer) devices. The CAL12 actuators have 10mm stroke lengths and have been designed to offer precise, repeatable force control and positioning. They can also perform precise measurements of surfaces.

The actuators are based on a proprietary MCA technology covered by several patent applications. The stainless-steel devices allow free and independent, simultaneous control of velocity, position and force. A “soft-land” function allows a delicate, controlled force when landing on fragile components. It also allows indexing and establishing a datum by finding the surface of the part and setting that point to zero. Set-up and re-calibration are said to be simple.

Feedback is built in, so no external switches or sensors are needed to detect the cylinder movement or position. This cuts costs and the need for external wiring.

The actuators can achieve accelerations of up to 10G and have a life expectancy of at least 100 million cycles. They can deliver forces from 0.2–2N, and offer a choice of encoder resolutions from 5µm down to 100nm. UK prices start at around £500.