Disclosed herein are apparatus and methods for linear actuators that can deliver strokes and forces at different values. The linear actuators include both multi-coil and single-coil actuator designs. The linear actuators include a controller that is removably or permanently coupled to a piston assembly having any number of coils. An encoder may also be removably or permanently coupled to the piston assembly. The piston assembly, controller and encoder move as one unit during actuation of the linear actuator.