Since a rotary viscous damper works to smooth out movements of panels, arms, monitor screens, safety doors & similar components, sometimes special movement is required which needs a force applied which can be controlled.  A spring is one of the most reliable devices to apply force which you can attach to a rotary viscous damper.  The type of spring can be almost anything: torsion, tension, compression, power, flat etc. As a mechanical design company we can assist in the proper configuration to achieve your desired motion. Contact us at www.mmtech.us