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Scale-models glossary of terms-Radio control transmitters.

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  • wonwinglo
    • Apr 2004
    • 5410

    #1

    Scale-models glossary of terms-Radio control transmitters.

    Lets work our way down a basic radio control transmitter and explain a few basic terms and features-

    Antennae-Usually screwed into the top either vertical or at a slight angle,the antennae must be in good condition and kept clean for maximum reflection,make sure that it is also fully extended.Pointing the antennae away from the model in the event of an emergency such as range problems.

    Range Check-Allied to the above,do a range check with the antennae retracted, and walk away from the model which is positioned at its worst reception ie on the ground,follow manufacturers guidelines,'x' yards with 'x' amount of antennae extended,as servos start to chatter then raise next portion,have helper give hand signals,ie hands extended means servos working,hand down servo not functioning.

    Note that in the case of aircraft ground range is doubled in the air.

    Meter-Two types of meter show either RF output or battery voltage,graduated into colour segments,ie red low,however use meter with caution as rechargeable batteries can drop dramatically and the meter is only a guide,leave a safe margin to get the model safely back.

    Most modern TX have a combined meter but not always,use it like a fuel tank gauge ie as a guide.

    Computer radio-Transmitter ( TX) that has a facility to store model memory,could be say six models etc,some TX have modules that can extend memory for more models,these plug into the side of the TX.

    Gimbal-refers to device that the TX sticks are connected to,ie left stick can give say left right rudder,throttle on fore and aft stick.

    Mode 1 & 2-Set up of the transmitter,ergonomic layout 2 refers to throttle left,ailerons etc on right,vice versa for mode 1

    Personal preference but if learning from instructor make sure that you decide on one and stick to it !

    Trims-Each function has a trim to adjust the servo remotely to trim for any natural turn or bank,once adjusted in flight etc land and reset servo with trim at centre.

    Buddy lead-Plugs into the side whereby instruction can be given by linking two transmitters together,instructor can isolate beginners TX by depressing switch or holding down button.

    Charging lead/socket-Charging points on the side to either charge TX or RX as seperate units or together via a mains charger.

    Remote lead-Some TX have a facility to plug a remote lead into the side when setting up model indoors,normal TX antennae is then removed for testing direct to the RX via the said lead.

    Servo reversers-Tiny switches usually well out of the way under a plastic flap,enable the servos to be reversed via the transmitter.

    Warning-always make sure the switches are fully over and not half way after adjustment,always check the orientation carefully afterwards.

    XTAL-Or Crystal,small cultured chip that resonates to the precise frequency on a set of permitted frequencies.

    27 mhz have a colour code to identify the frequency and displays as a coloured flag,35 mhz use the frequency number usually on an orange pennant.

    Flyers/boaters/car enthusiasts have 'Frequency board' which has identical frequency numbers,a peg is placed on the board when the TX is in use.

    TX Mit-A device that fits over a transmitter to protect the modellers hands in adverse weather.

    Power switch-Swith usually recessed into the transmitter case which turns the TX on and off,normal sequence is TX on first after first checking if frequency is available ? then RX ( Receiver ) this avoids servo over-ride and stall out,to switch off reverse procedure ie RX off,then TX off.

    Tip-When taking a model out for the very first time always get a friend or buddy to check the controls again,it is so easy to get ailerons etc rigged up the wrong way round which can spell disaster,check twice fly/sail/drive auto once,above all check everything on frequent basis,it is surprising what you will find damaged or faulty,take no chances.

    We will deal with check lists some other time.
  • John
    Administrator
    • Mar 2004
    • 4641
    • John
    • Halifax

    #2
    Very useful info, thanks Barry
    www.scalemodelshop.co.uk

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    • wonwinglo
      • Apr 2004
      • 5410

      #3
      Scale-models glossary of terms-Inner controls on radio controlled aircraft.

      Here are some terms and usages,for the many and varied types of control systems in model aircraft,it should prove useful to beginners confronted with a myriad of descriptions on plans and instructions-

      SNAKE-This term refers to a plastic tube within which is normally a fluted plastic inner,usually used for control runs whereby there is an acute bend,END FITTINGS are usually self tapping threaded metal CLEVIS fittings but not always,the snake is held in place with tie-wraps at the various formers and exits through the side of the fuselage.

      END FITTINGS-take many different forms,usually metal clevis type devices which clip over the SERVO ARM and control surface HORN,for safety they are locked with either a locking nut or a small piece of neoprene tubing placed over the control end.

      SERVO ARM-plastic arms which fit onto the servo itself via splined shaft,the horn is locked onto the servo with a small SELF TAPPING screw,arms can take many forms depending on the application,rotary arms lend themselves to incorporating aileron/control surface differential,adjustable arms can also be used for adjusting throttle throws etc.

      SELF TAPPING SCREW-Otherwise known in industry as PARKER KALER after its originator,hardened screw which self taps into softer materials,useful tip here is when replacing the screw back off in anti-clockwise direction one full turn thus picking up the original thread.

      CLOSED LOOP-system is used when scale fidelity is required,usually two fishing trace lines connected to dual control surface horns,these can either go straight to two ends of the servo arm or to a slave bellcrank within the fuselage itself,various types of adjustment can be incorporated the easiest being two brass collets attached to the servo arm,split pins are placed within the collets and locked up when correct tension is placed onto the control runs.

      PUSHROD-control is usually an inner hard balsa rod to which are bound the end clevis fittings via bicycle spokes placed at right angles into the rod.

      GROMMETS-rubber/synthetic grommets placed into the fixing holes of servos,these serve to absorb vibration thus not transmitting it to the sensitive servo,ie to dampen,inside the grommet is placed a STAND OFF brass collet,carefully screw down until it just bites against the stand off within the grommet.

      BOWDEN CABLE-plastic outer sleeve to which there is a twisted metal inner cable,ideal for throttle runs,the end clevis fittings are screwed onto the inner cable and are thus adjustable.Tip-apply solder to the stranded ends of the inner cable before cutting with bolt croppers.

      BELLCRANK-Various types and angles,used for linking ailerons or high set all moving tailplanes on gliders and sailplanes,any application whereby the control function as set at right angle to the servo itself.

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