EX-NEXT w/KR-420XT(Short) Double Receiver

No. 10664

<Includes Serial compatible receiverKR-420XT>
●Dimensions:240.5×163.0×107.2mm(Does not include protrusions)
●Weight: 551g(battery not included )
●Power supply: AAA size dry battery, Ni-MH battery x4 (sold separately)
 Li-Fe battery(2cell 6.6V)(sold separately)
 Li-Po battery(2cell 7.4V)(sold separately)
●Current: 200mA or less
●Channel:PWM 4ch/ Serial 8ID
  *Maximum setting ID number of serial is different by each product.
●Frequency: 2.4GHz
●Radio Mode: XT
●Model memory 50
●Compatible receiver: KR-420XT, " MINI-Z EVO Receiver Unit EX-NEXT MC-8"

*This product’s manual is not included in the package, pleasedownload from  here.
*If you use Li-fe, Li-po, you must use with our option unit (Battery stand Unit).
*Can not use LCD Xpansion unit EXP-104 series.
*Can not use FHSS or DSSS receiver. (KR-418FH KR-415FHD,KR-210S etc)
*The product photos on this site are prototypes, which may be different to production models.

  • [World record response] KOPROPO's "NEXT” Stage

    * According to our research in October 2020 using 2.4GHz radio for RC car.

    Equipped with a new standard "XT" that achieves the fastest communication speed in the industry​.

    You can choose and use from "XT advanced mode" which is the world record response for one way communication and "XT telemetry mode" which is compatible for Telemetry ( 2 ways communication).



    XT Advanced Mode

    An all new control software and radio communication software of the EX-NEXT has been developed.  World record communication response and High resolution control are installed. 
    "XT Advanced mode" that is the highest speed in EX-NEXT is about 3 times the speed of the EX-RR. 
    The performance far exceeds the conventional high-speed communication.

    High-speed communication in the XT advanced mode improves the information density that will be sent to the receivers. 
    You will feel a "Fine and smooth maneuvering feeling" by unprecedented high-definition and high-resolution control when operating.

    XT Telemetry mode

    EX-NEXT supports "XT Telemetry mode" that uses 2-way communication. When "4S series servos" that support serial compatible are connected to the B/S port in the new receiver KR-420XT, you can use "REAL TIME ICS". So, you can easily change parameters of servos from the transmitter without accessing the car directly. Setting your car with more freedom and more detail without compromise.

    Also, even using the XT Telemetry mode that is 2-way communication, the High-speed response is still faster thanthe EX-RR.

    High speed supported by Serial servo.​

    Currently mainstream servo control method is performed by PWM control. PWM control method uses pulse width to send position of servos output from receiver. Serial control method uses a digital signal value to send the position of the servo output. So, communication speed of the Serial control method will be significantly faster than a PWM control method, time ofthe servo’s action from your operation input is shorter. Operating feeling will be ultra high speed like operating thecar directly.

    <Compatible servos> RSx4S / BSx4S Series


    *Servo is sold separately.

    Supported HCS.

    EX-NEXT & KR-420XT support the use of HCS that was adopted from the RSx3, BSx3 series. Until now, it was necessary to change the receiver mode using the settingdevice, but with EX-NEXT this can be changed from the transmitter for each channel. HCS compatible servos are automatically change to HCS mode when the received signal is HCS. If you want use HCS, please connect servos to 1-4ch ofthe KR-420XT.

     <Compatible Servo> RSx3 / BSx3 / RSx4S / BSx4S Series



    NORMAL mode

    YYou can use different kinds of servos by changing theresponse mode to "Normal mode". So, you can use most current servos and ESC with EX-NEXT.

    In this case, pleaseconnect to 1-4ch of the receiver.
    *If you change the response mode of EX-NEXT from NORMALto XT advanced mode in the radio settings, the maximum movement degrees of servos are limit to maximum about 42 degrees and will change. So, if you use NORMAL mode were commended setting to XT telemetry mode in the radio setting. In case of using an ESC, there is no chance of using over a travel limit, so there is no problem using with XT advanced mode.


    Firmware Ver.2.00 compatible with MINI-Z

    Firmware Ver.2.00 is released to use MINI-Z EVO with EX-NEXT.

    If you already have EX-NEXT

    If you already have EX-NEXT, you can update it to Ver. 2.00 to make it compatible with MINI-Z EVO. Please download the software and files necessary for uploading from the following links.  *The ICS USB Adapter HS is required for the update.

    "EX-NEXT Updater, Update file"

    *"MINI-Z EVO Receiver Unit EX-NEXT MC-8" is not included in this set.
    *EX-NEXT "MINI-Z Mode" and "MINI-Z EVO Receiver Unit EX-NEXT MC-8" do not support the telemetry function.
    *The conventional "MINI-Z EVO Receiver Unit 82040" is not compatible with this product.


    Ultra small receiver KR-420XT

    Port on the KR-420XT

    The figure below shows the ports of the KR-420XT. There are a total 5 ports. Yhe most right port is the B/S port. In case of using serial mode compatible servos, connect to this port.
    1-4 ch are same function as conventional KR-418FH and KR-415FHD. You can use conventional servos in these ports.


    Equipped with a terminal compatible for serial communication​.

    KR-420XT supports “REAL TIME ICS" that is a new serial communication to servos . You can use "REAL TIME ICS" by connecting to the B/S port using the BSx4-one10 Grasper2 that supports serial communication.

    There is only one B / S port, but you can connect two or more devices by changing the device ID number and using a twin extension cable. You can use "REAL TIME ICS" in a GP car orother categories too.

    Example for wiring serial servo.

    If you use 2 servos with GP car, connect the 2 servos to theB/S port using the Servo Twin Extension Wire II w/new plug. It is necessary to change ID number to 2 for the throttle servo, but it is easy to change by connecting it to the Xpansion of EX-NEXT. 

    Ultra small dimensions case​

    The ultra-compact receiver KR-420XT, which is equipped withthe latest devices abundantly for the EX-NEXT. While maintaining the same footprint as the KR-418FH compact receiver, which has been very well received, the connector mounting height has been reduced, and the total volume is smaller then before. 5 Connecting ports for servos or ESC areequipped. Also, unused connecting ports can be use to power cooling fans and transponder for lap counting systems.

    Install antenna pipe to receiver case directly.

    KR-420XT has the capability to install an antenna pipe toreceiver case directly just like the KR-415FHD, which has been very well received. The footprint is the same as the conventional model KR-418FH, but you can save the troubleof installing an antenna mount.

    Example of installing an antenna pipe.

    Pairing device without Power cycle.

    The UI (user interface) of the setup switch and pilot LED hasalso been reviewed. In addition to the same handling as the conventional KO PROPO receiver, pairing and RF mode switching functions have been additionally implemented without turning the power on / off.KR-420XT has the capability to install an antenna pipe toreceiver case directly just like the KR-415FHD, which has beenvery well received. The footprint is the same as the conventional model KR-418FH, but you can save the troubleof installing an antenna mount.


    Intuitive alert function with vibration and full-color LED

    Equipped with a vibration motor that has been requested. Thiscan be used for alarms that notify the running time and alerts for various sensors. In addition, the LED on the front of the master unit is a full-color LED. The radio wave mode in useand the alert content of the vibration motor can now be identified by the LED lighting pattern.


    Xpansion 2 that can change the ICS setting of the servo is standard equipment.​

    EX-NEXT is equipped with the evolved "LCD Xpansion unit 2 EXP-201" as standard equipment. New telemetry, XT radio mode, supported menu, and also the newly added setting function for ICS compatible servo are standard. Serial compatible servos which support "REAL TIME ICS" and conventional ICS compatible servos can be used. Changesettings of an ICS servo by only using the Xpansion unit 2 without using a PC or servo model selector.

    *It necessary to use external power (6 to 7.4V) for setting byXpansion unit 2 only. Please use the "Servo Twin Extension Wire II w/new plug" for power supply, sold separately.



    New Drop down extension Unit 2.1

    Tune up for EX-NEXT

    Tuned for the evolution of the EX-NEXT to match the fastest feeling master unit as an exclusive use unit.

    Superior durability and operation feeling led by new angle sensor.

    Prevents deterioration of durability and operational feeling due to wear, which can be said to be the problem of contact sensors. Along with smooth operation feeling by smoother sliding, we realize high durability that is approximately 100 times compared with the prior sensor. Therefore, the best feeling of operation can be maintained for a long time. In addition, the new sensor outputs a more linear signal to the Master Unit. You can control the ESC and servo with a detailed operation sense. A realization of a sense of unity between people and cars.

    Increased the number of ball bearings that support the steering shaft for higher accuracy!

    The number of ball bearings supporting the steering shaft has been increased from one to two. The double-support type supports higher precision operation and reliability.



    The soft spring which can be operated with a constant tension.

    The normal spring included in the extension unit has been modified. The previous spring used was a progressive spring becoming stiffer as the wheel angle increased, but the new softer spring give a linear stiffness as the wheel angle increases. Since the spring tension can be adjusted, you can set the spring tension to your personal preference.


    Firmware update function.​

    Firmware update function is supported with the use of the ICS USB Adapter HS.
    Please refer below pages for information about update.
    EX-NEXT Updater, Update file

    *Window PC and ICS USB adapter HS are necessary for update.
    *Firmware for EX-NEXT can only be used for this product.  It cannot be used with EX-RR/LDT/2/6/6R.


    EX-NEXT function list

    RF mode/Response/REAL TIME ICS/Battery fail safe

    Model select /Model name/ Model copy /Model reset /50 model

    Display / Battery / Calculator / Sound/ VR infomation / Setting /Key speed /Menu speed  /Display language / Operation timer /User timer / All reset

    Travel/ Balance / Trim /Sub Trim / Trim rate / Speed turn(2way) / Speed return(2way) / Curve / Punch / Feel / Response / Steering Auto Trim /Steering Auto balance/Reverse

    <Throttle>Travel F / Travel B / Trim /Sub trim / Trim rate / Speed turn(3way) / Speed return(3way) / Curve / Punch / Feel / Response / Push control / Acceleration / ABS /Auto Start / Idle up / Neutral brake / Over ride / Reverse / Brake in / Hand brake

    Key setting/ 2WAY / 3WAY / 5WAY / Analog/ Gyro / Twin servo / 4WS/AMP mixing
     /Throttle mixing / Trim set 

    Key setting/ 2WAY / 3WAY / 5WAY / Analog

    Timer Start / Trigger start / Lap history / Start stop key/Lap key /Lap navi / Ararm time/ Pre aram / Aram mode / Timer mode (Lap timer/ Down timer)



    Master Unit EX-NEXT ×1
    LCD Xpansion Unit2 EXP-201 ×1
    Aluminum Steering Wheel5 x1
    Drop down  extension Unit 2.1 ×1
    Expert grip unit 2 (White) ×1

    Receiver: KR-420XT ×1

    *Battery, Dry batteries are sold separately

  • EX-NEXT w/KR-420XT

    No. 10661

    KR-420XT 2.4GHz

    No. 21013

    Aluminum Screw set EX-RR/EX-2/LDT/NEXT(blue)

    End of production
    No. 10674

    Color Grip2(white)

    No. 10590

    Color Grip2(Pink)

    No. 10589

    Color Grip2 (Blue)

    End of production
    No. 10532

    Color Grip2( Gray)

    No. 10530

    Large Grip Black for KIY

    End of production
    No. 10503

    Large Grip Gray for KIY

    End of production
    No. 10514

    Large Grip Green for KIY

    End of production
    No. 10515
  • Radios

    Drop Extension Unit 2.1 Instruction Manual

    LCD Xpansion unit 2 EXP-201 Startup Guide

    EX-NEXT Instruction Manual

    Radios Manager

    EX-NEXT Backup Manager Software
    This software is used to save the model data in the radio to the PC(Windows).

    EX-NEXT Updater, Update file Ver.3.00

    EX-NEXT Updater, Update file Ver.3.01

  • Released EX-NEXT latest update file.
    EX-NEXT Explanation of "battery fail safe".
    Next-generation transmitter "EX-NEXT" [1]