now please do not disturb your Rx setting as it is poor innocent one to work with..
we have ample of ways to drive a DC motor in either directions..may be an ECM, ( Electronically Commutated Motor, or Brush Less), or an MCM,( Mechanically Commutated Motor)..to drive a DC or AC motor, we must need a speed controller, more clearly a motor controller and it must not be an ESC..( electronic speed Controller)..we can also control of the speed and torque of a motor by means of mechanical methods..so, here we have two ways to choose..one mechanical and one electronical..at first easiest way..the mechanical..i told you, at present, you have a Tx, Rx battery packs to operate it, and yes at least two servos..surely, wee need one servo, for steering control, while one left..so, we will connect the steering servo, to one desired channel of Rx..the second one will be connected to the throttle channel..now fix a servo drive arm to the srvo drive shaft..switch on your radio set..centre the trimmer..and make sure, the arm of the throttle control servo is straight..then fix the servo, on a piece of platic sheet, foam board, or on a common PCB, and you can attach two smaller switches in to the two sides of the servo arms as shown..

each switch have 3 terminals..and one of the terminals for each switch will be the pole..connect two wires from motors to pole..and connect the battery + and battery - to the Nc No contacts of the one switch..and connect the same wires in opposite to the second switch..so, at present, when the servo arm stays at centre, two sitches will be as in OFF position..because the motor will get same two terminals from battery..so it wont turn..but when the servo arm pushes a swithc, the motor will get one polarity, through switch, and start to turn to one side..and yes in opposite, when servo arm pushes the second switch..we can also add a compound switch for more compactness..see here..

from here you can see its morecompact and versatile..this switch can hold up to 15 amps at 12 volts dc..now we can drive our motors with ease in clock and counter clock directios..and any heavy motor..but still have a infermity..is cant control the speed..while cruising..it will works only on a predettermined voltage..as switches..here comes the importance of a ESC..is Electronic Speed Controller..

Naatu..now our vehicle is running..you can simply increase or decrease the speed and power of the vehicle by adjusting battery numbers..
so, now about ESC..when we thinks about an ESC we think some thing big..its all nothing but some simple circuit..what we need to make an ESC is a signal streacher, or a pulse expander..   ?   ..yes..i told you, the out put from the Rx will be 1.5 m/s at stick at centre, and 1 at stick at one end, and 2m/s at stick at other end..so, we will get the same signal pulses at the out put of the Rx staying far away from Tx..so, we must need a circuit, that circuit must gives us a positive voltage as ouput, when the signal from Rx reaches to 1m/s..and there must not be any voltage from it, as the signal from Rx reaches 1.5 m/s..but again this circuit must gives us a negative voltage when the Rx signal reaches 2 m/s..and it must be all proportinally..means, the voltage, from the circuit, must be in positive or negative, not instantly, but it must increase gradually to maximum, as we pushes or pulls the Tx sticks to desired levels..to achieve this we have ample of integrated circuits in markets, and such ICs are leberally used in DVD, VCD player boards..this kind of Ics are far cheaper, costs about Rs 20/- and works well..for an example, M 51660 L is one of the beast Ic, i ever used, that can drive a 800 mA DC motor rated at 7.2 volts..in either directions..

now we have the motor driver..still this one is not capable of driving a heavy motor..so, with this IC, we can use a H bridge circuit, that you can simply attain from any Hobby electronics Books, from any good book stall..costs about a 30 Rs/-..remember..buy some circuit books for you, as books are far beyond explanations than looking in to a web site..make sure the purchased book is from a reputed publisher, like BPB,ITE, EFY...those books will lead you ample of good stuffs..because we can simply place the book in front of us, while working and can go for many repeated readings and references in realted subjects..that you need not any power source to switch on it..and instead of wandering behind some thing, make a clear idea about needed circuits..follow some strict rules while assembling an electronic circuit..sucsess guranteed..

if you feel a H bridge circuit is far complicated, you can simply make an ESC with a micro servo, and a MOSFET, in IRFZ48..this MOSFET can hold a current up to 40 Amps at 12 Volts..and costs about 20 Rs/-..how to make it..? easy..remove the back cover of your micro servo, de solder one of the motor lead from motor of the servo..attach a long wire to the same motor wire..this is your pulse ouput..cover back the servo..you can make an arrangement with an other or existing battery pack to MOSFET, and can feed it to motor, and can drive it with the pulse from servo..can also add reverse with the early mentioned switces, while adding it to an other channel of the radio..so, you can alter the speed from 0 to full in FWD and REV eaqually..

now even more easy way..take a standard or heavy duty servo..remove all thigs from it..except the PCB and motor..connect it to throttle channel of Rx..switch on..so, will find the motor of the servo running in any of the direction..be cool..turn the potentiometer of the servo, on it's PCB, to any of the directio..make sure the throttle stick of the Tx is at centre..so, after a particular point, the motor will stops spinning..now you can pull or push the Tx throttle stic to desired position..and can see the servo motor is running in either direction with respect to your stick inputs..and in proportional manner..so, do not try to remove the brass gear of the motor, as this can damage the motor..instead you can add a silicon drive grear by drilling it, and attching it on to the brass gear of the motor..so can drive any platic gear box, with it..if not, you can solder a new Dc toy, or a tape recorder motor, bgut sure not a RS series motors..and can add any motors rated within 1 Amps..so, can add a robotic gear box, toy car gear box..works well..in FWD and REV..without any extra ordinary materials..this also can be used in boats..and many otherapplications..if need more instructions tell me..Naatu, with this time, if you were near to me, we can make more than 3 vehicles..hi..hi..so, now time for my medicines..Mom shouting a lots..see once again..its all simple..make a lots of cars and vehicles..because even a HD servo costs a mere 450 Rs now..make sure it is in a good company..i found many standard servos with a bord of micro servos in it.. this kind of servos are for making us all fools..so, make sure the standard servo, or hd servoas are with a heavy PCB with a big Ic in it..or with transistors with it..so..dont be lazy..make cars..tanks..robots..boats..trains..planes..

Naatu..i will make a little RC car from two servos to clear your doubts..