how to send command to all bldc motors at once?

hi im making a quadcopter.i have written this code to calibrate esc's

#include"Servo.h"
#define MAX_SIGNAL 2000
#define MIN_SIGNAL 1000
#define MOTOR_PIN 3
#define MOTOR2_PIN 5
#define MOTOR3_PIN 6
#define MOTOR4_PIN 11
Servo m1,m2,m3,m4;
void setup()
{
m1.attach(MOTOR_PIN);
m2.attach(MOTOR2_PIN);
m3.attach(MOTOR3_PIN);
m4.attach(MOTOR4_PIN);
m1.write(MAX_SIGNAL);
m1.write(MIN_SIGNAL);
delay (5000);
m2.write(MAX_SIGNAL);
m2.write(MIN_SIGNAL);
delay (5000);
m3.write(MAX_SIGNAL);
m3.write(MIN_SIGNAL);
delay (5000);
m4.write(MAX_SIGNAL);
m4.write(MIN_SIGNAL);
delay (5000);

}

void loop()
{

m1.writeMicroseconds(1400);
m2.writeMicroseconds(1400);
m3.writeMicroseconds(1400);
m4.writeMicroseconds(1400);

}

the problem with this code is in the loop.
the motors spin in order and stop one by one and the repeat the same thing.
how do i make them spin constantly and together.
im new to this so please bare with me

how to send command to all bldc motors at once?

Connect one servo out pin to all four bldc input wires.

 delay (5000);
  m4.write(MAX_SIGNAL);
  m4.write(MIN_SIGNAL);

That won't do what you think - the time between the two write() calls will be a few
microseconds at most, so the first one will have absolutely no effect since there's not
enough time for any servo control pulses to go out.

You probably need to go and look at BlinkWithoutDelay() and see how to drive
things without using delay(), since you've multiple devices to control.

Doing this is as close to "sending command to all bldc motors at once" as you'll need:

  m1.write (m1_level) ;
  m2.write (m2_level) ;
  m3.write (m3_level) ;
  m4.write (m4_level) ;

I've a nagging suspicion you might be expecting the ESCs for each motor to
have identical calibration. They won't.

However that's not such an issue, you'll need closed-loop control anyway to have
any chance of stable flight so this doesn't matter much (the moment of take off
is a tricky one though).