Using arduino mega is making my cnc claw buggy. Help

Question

I have three nema 23 steppers with one 8 channel relay(all the pins used) powering two dc motors and 4 IR sensors for feedback on the machine.

The problem is my machine is working fine for only 2 to 3 minutes until it just resets itself in the middle of the routine and crashes my whole system.

I am using 1/2 step microstepping with TB6600 stepper driver. Also my arduino is mega 2560, maybe thats the problem I don't know about.

Here I am attaching the code

const int dirPin1=2;
const int stepPin1=3;
const int dirPin2=4;
const int stepPin2=5;
const int dirPin3=6;
const int stepPin3=7; 
int del=1;
void setup() {
 pinMode(2,OUTPUT);
 pinMode(3,OUTPUT);
 pinMode(4,OUTPUT);
 pinMode(5,OUTPUT);
 pinMode(6,OUTPUT);
 pinMode(7,OUTPUT);
 pinMode(8,OUTPUT);
pinMode(9,OUTPUT);
pinMode(10,OUTPUT);
pinMode(11,OUTPUT);
pinMode(12,OUTPUT);
pinMode(13,OUTPUT);
pinMode(14,OUTPUT);
pinMode(15,OUTPUT);
pinMode(16,INPUT);
pinMode(17,INPUT);
pinMode(18,INPUT);
pinMode(19,INPUT);
digitalWrite(8,HIGH);
digitalWrite(9,HIGH);
digitalWrite(10,HIGH);
digitalWrite(11,HIGH);
digitalWrite(12,HIGH);
digitalWrite(13,HIGH);
digitalWrite(14,HIGH);
digitalWrite(15,HIGH);
 
}
void picker_up(){
  digitalWrite(8,HIGH);
  digitalWrite(9,HIGH);
  digitalWrite(10,LOW);
  digitalWrite(11,LOW);
  delay(570);
  digitalWrite(8,HIGH);
  digitalWrite(9,HIGH);
  digitalWrite(10,HIGH);
  digitalWrite(11,HIGH);
  delay(100);
}
void picker_down(){
  digitalWrite(8,LOW);
  digitalWrite(8,LOW);
  digitalWrite(10,HIGH);
  digitalWrite(11,HIGH);
  delay(320);
  digitalWrite(8,HIGH);
  digitalWrite(9,HIGH);
  digitalWrite(10,HIGH);
  digitalWrite(11,HIGH);
  delay(100);
}
void claw_close(){
  digitalWrite(12,LOW);
  digitalWrite(13,LOW);
  digitalWrite(14,HIGH);
  digitalWrite(15,HIGH);
  delay(100);
  digitalWrite(12,HIGH);
  digitalWrite(13,HIGH);
  digitalWrite(14,HIGH);
  digitalWrite(15,HIGH);
  delay(100);
}
void claw_open(){
  digitalWrite(12,HIGH);
  digitalWrite(13,HIGH);
  digitalWrite(14,LOW);
  digitalWrite(15,LOW);
  delay(100);
  digitalWrite(12,HIGH);
  digitalWrite(13,HIGH);
  digitalWrite(14,HIGH);
  digitalWrite(15,HIGH);
  delay(100);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(dirPin1,HIGH);
digitalWrite(dirPin2,HIGH);
digitalWrite(dirPin3,LOW);
for(int i=0;i<=1200;i++){
  digitalWrite(stepPin1,HIGH);
  digitalWrite(stepPin2,HIGH);
  digitalWrite(stepPin3,HIGH);
  delay(del);
  digitalWrite(stepPin1,LOW);
  digitalWrite(stepPin2,LOW);
  digitalWrite(stepPin3,LOW);
  delay(del);
}
for(int i=1;i<=400;i++){
  digitalWrite(stepPin1,HIGH);
  delay(del);
  digitalWrite(stepPin1,LOW);
  delay(del);
}
delay(1000);
picker_down();
claw_open();
claw_close();
picker_up();
delay(2000);
digitalWrite(dirPin1,LOW);
digitalWrite(dirPin2,LOW);
digitalWrite(dirPin3,HIGH);
for(int i=1;i<=400;i++){
  digitalWrite(stepPin1,HIGH);
  delay(del);
  digitalWrite(stepPin1,LOW);
  delay(del);
}
for(int i=0;i<=1200;i++){
  digitalWrite(stepPin1,HIGH);
  digitalWrite(stepPin2,HIGH);
  digitalWrite(stepPin3,HIGH);
  delay(del);
  digitalWrite(stepPin1,LOW);
  digitalWrite(stepPin2,LOW);
  digitalWrite(stepPin3,LOW);
  delay(del);
}
delay(2000);
}

I am not getting why this is happening. Or do I need some more electronic components included in the machine and I know I could have used mosfets to control the motors but I am just way too lazy.

I used uno before this and it used to work fine, so should I just go back to using it?

Also I have modified the code to be compatible with the uno again so please bare with the pin numbers.