3D printed Servo valve 4mm

[shiva]

Do you like to water plants automatically? if yes then this would be for you and if you have few plants only.
This is very small shut off valve made for 2 or three plants as it is 4mm connector connected to servo motor.

Please see the video.  
https://www.youtube.com/shorts/42ItEEk8yOg

[ramesh]

Leaks are the eternal battle with printed valves. You can't rely on the printed plastic-on-plastic for a seal at this scale.

My advice:

Embed a Seal: You need to modify your design to include a small groove for an O-ring. A 1mm cross-section O-ring would be perfect. You can buy a meter of silicone O-ring cord for cheap and glue the ends together for a perfect custom fit.

Material: PETG is okay for the body, but if you're using any aggressive chemicals, you'll want to move to ABS or ASA (better chemical resistance and you can smooth it with acetone for a better seal surface) or even Nylon (though it's a pain to print).

Stalling Servo: This is likely due to friction. An O-ring will actually reduce friction compared to a tight plastic-on-plastic fit. Also, ensure your ball is as spherical as possible. A light sanding might help.

Don't give up! The learning process is worth it.

[admin]

Yes — this is a DIY 3D printed servo valve. It uses a small hobby servo motor (like SG90 or MG90S) connected to a 3D-printed valve body that controls water or air flow.

Here’s how it works and what you’ll need if you want to build one:

### **Components:**
- Servo motor (SG90 or MG90S)
- 3D printed valve body and lever (PLA or PETG recommended)
- PVC or garden hose fittings
- Screws and nuts for servo mounting
- Arduino / ESP board to control servo
- (Optional) Potentiometer or sensor for feedback

### **Working:**
- The servo rotates the valve spindle by 90° or less.
- This rotation opens or closes the flow path.
- Controlled by PWM signal from Arduino or microcontroller.

Arduino code

Code:

#include <Servo.h>
Servo valveServo;
void setup() {
  valveServo.attach(9); // Signal pin
}
void loop() {
  valveServo.write(0);  // Valve closed
  delay(3000);
  valveServo.write(90);  // Valve open
  delay(3000);
}

**Tips:**

- For water use, make the valve parts watertight with silicone grease or O-rings.
- For air or low-pressure systems, PLA is fine; for higher pressure, use PETG or ABS.
- You can integrate it into smart irrigation, aquarium systems, or robotic control setups.

[shilparamam]

This is a great ambitious project. From an engineering standpoint, you're fighting several battles:

Tolerance & Surface Finish: FDM printing inherently has layer lines that act as leak paths. Your sealing surfaces need to be smooth. Consider designing your valve for a press-fit silicone diaphragm instead of a ball. The servo would actuate a plunger that presses the diaphragm onto a seat. This is a much more reliable sealing method for additive manufacturing.

Creep: Both PLA and PETG will creep (deform over time) under the constant pressure of the seal, eventually leading to failure. This is another point for Nylon or PP (Polypropylene), though both are challenging to print.

Stall Torque: Calculate the required torque. The SG90 has ~1.8 kg-cm. With a 4mm orifice and even low pressure (e.g., 10 PSI), the force on the ball can be enough to stall it. Your stalling issue is almost certainly a combination of friction and fluid pressure.

I second the O-ring suggestion. Redesign for a seal; it's non-negotiable for a reliable valve.