[NSRCA-discussion] Futaba S9155 Hi Torque servos

[ppennisi]

I am thinking of purchasing some of the new Futaba S9155 servos for rudder
use on F3A models. Information taken from Tower's website state that it
should only be used in 6 volt NiCad powered systems.

Does anyone see any problems using this servo in a regulated 5.6 volt
environment using a Duralite regulator and 2 cell 2350 mah Lithium Ion
supply.  


Here is the information taken from their site


This is the Futaba S9155 Digital High Torque Metal Gear Servo.
                           with J Connector.
                      Designed for aircraft applications
            This servo requires high-current draw from batteries.
                         Use 6V NiCd batteries only.

FEATURES: Coreless motor, see COMMENTS
          Digitally enhanced microprocessors cut in half the response time
            from transmitter input to servo reaction
          Center of case is metal
          One year warranty

INCLUDES: One S9155 Digital High Torque Servo with J Connector
          Round servo wheel 1.8" (45mm) diameter
          Four point servo wheel 1.5" (38.5mm) diameter
          Six point servo wheel 1.2" (32mm) diameter
          Four rubber grommets
          Four metal eyelets
          Four 2x11mm mounting screws
          3x8mm horn set screw

SPECS:    Speed:        0.13 sec/60 deg @ 6.0V
          Torque:       192 oz-in @ 6.0V
          Length:       1.57"  (40mm)
          Width:        0.79"  (20mm)
          Height:       1.44"  (36mm)
          Weight:       2.15oz (61g)
          Power Supply: 6V required

COMMENTS: S9155 Digital Servo Precautions,
           -It is best to avoid long leads and Y-harnesses especially with
            standard grade wires. If problems are encountered, consider
using
            heavy duty wire such as Futaba's Heavy Duty Series or Hobbico's
            Pro Series, minimizing lead lengths, and/or removing
Y-harnesses.
           -Current Drain: This digital servo is specially designed for
high-
            torque or high-speed, therefore very high current drain is
normal
            at startup. For ultimate performance when using this servo
please
            review the following points.
              1. Radio systems with the Battery Fail Safe function have a
                 higher cut-off voltage setting which will cause shorter
                 operation time.
              2. When installing the servo, please check pushrod linkage to
                 make sure there is no binding in order to prevent excessive
                 power consumption and decrease the life of the motor and
                 battery.

         A note on Coreless motors: conventional servo motors have a steel
           core armature wrapped with wire that spins inside the magnets. In
           a Coreless design, the armature uses a thin wire mesh that forms
a
           cup that spins around the outside of the magnet eliminating the
           heavy steel core. This design results in smoother operation and
           faster response time.

         This digital servo cannot be used with any AM transmitters
including
           the following Futaba models as the servo neutral signal is:
1310us.
           CONQUEST AM, FG Series (T4FG, T5FGK,T6FG, T6FGK, T7FGK), New
Terra-
           top, T3EGX, T3PGE, T2NL, T2LGX, T2FR, T2PK series.