Controling a ball valve

Hi, am an new to this and all those forums and google just makes me go in circles :-) but i need to open and close 6 3/8" ball valves and the medium is air to inflate and deflate car tyres. The valves only travel 1/4 turn to fully open and close . I will be using servos and on off buttons. Can somebody spec this up for me the easy way? Br. Elmar

servos

What do you mean by "servo"?

Regards

Do you know how much torque is required to move the valve? That will be essential knowledge before selecting a motor.

...R

The vales are very light to move so torque is not a problem for example 40-99 oz-in is a high toque RC servo that i could use. /// Torque: 72oz/in @ 4.8V 88oz-in @6V /// Br Elmar

Have you looked at the servo and button code examples that come with the Arduino IDE?

If you have a toggle switch the code might be as simple as

void loop() {
   switchPos = digitalRead(switchPin);
   if (switchPos == HIGH) {
      myServo.write(150);
   }
   else {
      myServo.write(60);
   }
delay(500);
}

One problem you might have is that the servo wants to move too quickly. If so look at the servo sweep example code.

...R

Some servo two button code. Servos might work turning ball valves, but it has been my experience that ball valves require a significant amount of torque to rotate.

//zoomkat servo button test 12-29-2011
// Powering a servo from the arduino usually *DOES NOT WORK*.

#include <Servo.h>
int button1 = 4; //button pin, connect to ground to move servo
int press1 = 0;
int button2 = 5; //button pin, connect to ground to move servo
int press2 = 0;
Servo servo1;

void setup()
{
  pinMode(button1, INPUT);
  pinMode(button2, INPUT);
  servo1.attach(7);
  digitalWrite(4, HIGH); //enable pullups to make pin high
  digitalWrite(5, HIGH); //enable pullups to make pin high
}

void loop()
{
  press1 = digitalRead(button1);
  if (press1 == LOW)
  {
    servo1.write(170);
  }    
  
  press2 = digitalRead(button2);
  if (press2 == LOW)
  {
    servo1.write(10);
  }
}

but i need to open and close 6 3/8"

I think that the OP just needs to (fully) open the valve: If yes, I wonder if he would manage with some simpler device.

Regards

Yes i just need to fully open and close the valves 1/4 or 90°. To use arduino is just for the fun factor of it :-) Also pressure meter will be a plus for it.

Found servos that Torque: 4.8V: 138.9 oz-in (10.00 kg-cm, it will be OK. http://www.servodatabase.com/servo/towerpro/mg995

Servos and valves will be in the engine compartment

vffgaston: I think that the OP just needs to (fully) open the valve: If yes, I wonder if he would manage with some simpler device.

Regards

I can use a solenoid valve for it but i like to try the arduino.........they are also weary expensive for the flow i need. The Switch is led light 12V car rocker off/on switch is analog a problem?

The reading material and information just so much on the internet :-)

Br. Elmar

emmibe: The reading material and information just so much on the internet :-)

Have you got all the info you need, or do you still have a question?

...R

6-3/8" ball valve ? sounds like you could inflate the entire daily production of car tires for FORD North America in a few seconds.

or, is that six ball valves, 3/8" dia each ? better/easier to use solenoids if you do not have them yet.

a suggestion when posting about devices is to post a link to the device.

ball valves are not linear so you will get lots of flow as soon as there is an air passage. I would offer that you should be able to find a setting that allows some air to flow, but is nearly closed. then as your pressure gets close to the desired pressure, closing will be very fast. much faster than if you started to close from a full open position.