This is the first version of my blaster compatible with the Nerf Rival rounds. The new version should have less parts, be cheaper and be quiter without the EDF.

2 x Racerstar BR2212 1800KV 2-4S Brushless Motor 1 x 35mm brushless EDF 3 x ESC 1 x N20 Micro Speed motor 1 x 4S LiPo 1 x Arduino Pro Mini 1 x h-bridge for controlling the feeder (not necessary)

https://youtu.be/qruwTxABoGA

Arduino code (not tested) : Requieres the servo.h lib

// motors : Servo motorTop; Servo motorDown; Servo motorEdf; int motorFeedHBridgeEn = 4; // "H-Bridge Enable" use the h-bridge to control the feeding motor int motorFeedHBridgeDirection = 2; // "H-Bridge input" use the h-bridge to control the feeding motor

// potentiometers : int wheelSpeed = 0; int wheelSpeedValue; int hopUp = 1; int hopUpValue; int edfSpeed = 2; int edfSpeedValue; int feed = 3; int feedValue;

// sensors : int counter = 5; // count the fired shots

// buttons : int trigger = 6; // control the feeding motor int rotate = 7; // start the wheel cage int loader = 8; // start the edf

void setup() { motorTop.attach(9); motorDown.attach(10); motorEdf.attach(11); }

void loop() {

// release the trigger, reset motors motorTop.write(0); motorDown.write(0); motorEdf.write(0); digitalWrite(motorFeedHBridgeEn, false);

// loading the rounds while(digitalRead(loader)){ motorEdf.write(edfSpeedValue); }

// arming the nerf while(digitalRead(rotate))){

// reads the value of the potentiometer (value between 0 and 1023)
// scale it to use it with motor (1500 "stopped" to 2000 "full speed") (with my esc)
wheelSpeedValue = analogRead(wheelSpeed);
wheelSpeedValue = map(wheelSpeedValue, 0, 1023, 1500, 2000);
hopUpValue = analogRead(hopUp);
hopUpValue = map(hopUpValue, 0, 1023, -100, 100);
edfSpeedValue = analogRead(edfSpeed);
edfSpeedValue = map(edfSpeedValue, 0, 1023, 1500, 2000);

while(digitalRead(rotate))){
  motorEdf.write(edfSpeedValue);
  motorTop.write(wheelSpeedValue - hopUpValue);
  motorDown.write(wheelSpeedValue + hopUpValue);
  while(digitalRead(trigger)){
    digitalWrite(motorFeedHBridgeEn, true);
    digitalWrite(motorFeedHBridgeDirection, true);
  }
}

// release the trigger feeds the motor backwards to avoid rounds jamming the wheelcage
int i = 1000;
while(i > 0){
  digitalWrite(motorFeedHBridgeEn, true);
  digitalWrite(motorFeedHBridgeDirection, false);
  i--;
}
// then turn the feed off
digitalWrite(motorFeedHBridgeEn, false);

}

}