caster vs control surface

caster

noun
  • A wheeled assembly attached to a larger object at its base to facilitate rolling. A caster usually consists of a wheel (which may be plastic, a hard elastomer, or metal), an axle, a mounting provision (usually a stem, flange, or plate), and sometimes a swivel (which allows the caster to rotate for steering). 

  • The angle of the axis around which a car's front wheels rotate when the steering wheel is turned, with a vertical axis being defined as zero caster. 

  • A shaker with a perforated top for sprinkling condiments such as sugar, salt, pepper, etc. 

  • A stand to hold a set of shakers or cruets. 

  • Someone or something that casts. 

verb
  • To act as a caster 

control surface

noun
  • A moveable surface attached to a machine such as an aircraft or submarine that can be used to control the machine's motion in roll, pitch or yaw. 

How often have the words caster and control surface occurred in a corpus of books? (source: Google Ngram Viewer )