Sprinkler with radially limited nutating spool

A fluid distributing sprinkler head, comprising,

• a fluid delivery tube in fluid connection with a nozzle;
• a sprinkler body partially enclosing said fluid delivery tube and nozzle;
• a spool assembly comprising,
• a spool having a generally cylindrical spool body and circumvolving said nozzle, wherein said spool comprising an annular disc;
• a distribution plate fixedly connected to said spool in a spaced apart relationship by one or more spool arms, wherein said nozzle is configured to direct fluid via a fluid path through said spool body and onto said distribution plate, said distribution plate having a generally peaked surface, said surface incised by spirally radiating grooves, said spirally radiating grooves configured to cause said spool assembly to nutate within said sprinkler body when impinged upon by fluid directed by said nozzle;
• an upper friction band and a lower friction band each circumvolving said spool, wherein said upper friction band comprises an upper friction band outer diameter and said lower friction band comprises a lower friction band outer diameter;
• wherein said sprinkler body comprising an upper race and a lower race on an internal surface of said sprinkler body so as to radially limit nutation of said spool within said sprinkler body, wherein at least one of said upper race and said lower race comprises a starter ramp, wherein said starter ramp is configured such that one of said upper friction band or said lower friction band contacts a lower end of said starter ramp, wherein said sprinkler is configured such that upon start up of fluid spraying on said distribution plate generating centrifugal force on said spool and driving one of said upper friction band or said lower friction band up said starter ramp and into its respective race;
• wherein said upper friction band and said lower friction band are spaced apart such that said upper friction band is configured to radially roll on said upper race on an inner diameter of said upper race when said spool assembly is nutating within said sprinkler housing and said lower friction band is configured to radially roll on said lower race when said spool assembly is nutating within said sprinkler housing;
• and
• at least one raised projection, wherein said spool assembly is configured to hang freely from said at least one raised projection by said annular disc when said spool assembly is without fluid and said sprinkler head is in a vertical position, wherein said driving of one of said upper friction band or said lower friction band up said starter ramp and into its respective race causes the lifting of said spool off of said at least one raised projection.