Our rotary viscous dampers have a unique feature: minimal part count to achieve the desired damping. This is especially noteworthy mainly because it keeps prices low and eases QC processes. We have had great success in achieving consistent damping over large quantity runs.  For example small diameter dampers are inefficient because there is a low damping coefficient compared to the amount of pieces in the design.  I am specifically talking about rotary viscous dampers that use discs stacked along the axis of rotation. They have damping grease sandwiched in between the discs. As you get closer to the center of rotation the velocity is very small and the effect of shearing fluid has negligent influence. We do not design with this specific configuration unless space requirements allow a efficient use of area.  Please contact us with your specific damping application at www.mmtech.us