WiFi Controlled 160mm Butterfly Valve

thingiverse

2021-07-30: Check bottom for update Here is a butterfly valve for 160mm tubes. You can control it via HTTP post commands: curl -X POST http://VALVE_IP/open curl -X POST http://VALVE_IP/close Here you can see it in action: https://www.youtube.com/watch?v=XwV787XyBs4 You'll need some stuff: - a Servo. I added a 41mm mount stl for the MG996R servo and a 39mm mount stl for a Graupner C-577 servo - an ESP32, I added a stl for a ESP32 Dev Board NodeMCU WROOM32. The code to flash is inside the airvent.ino file. You'll at least need to set your wifi name and password before flashing, but you'll most probably want to set a different servoPin (I used 13, its next to the 5V power pin) The current verison of code does the following: Changelog: * disables servo after command to make it live longer * reconnects wifi if disconnected * reconnects wifi if it looks connected but google is not reachable * lights LED while checking for google and switches it off when google was found successfully -> yes you read right. I had trouble with the esp32 losing wifi and not noticing it. Now it checks if google is reachable and if not it drops wifi and reconnects. While its checking for google the blue LED turns on and goes of if everything was fine. That means that there is a short blue led flash every 30 seconds when everything is fine and if it stays blue then wifi is lost or the wifis internet connection is gone. once network is back fine again blue led goes out and the valve resumes doing its valving thing... However, you'll most probably need to play around with the myservo.write() values in doOpen() and doClose() - here you set the positions of the servo in close & open states. I found mine wih try & error. - A power supply. Its voltage needs to be not higher then both esp32 and the servo support - 5V is a safe bet. Amperage depends on the power draw of your servo. Everthing >=2A should be fine. I use a beefy supply because I'm going to run many valves on it. - A bunch of M3 screws and nuts. 13-15mm length will do fine. many of them, 20 pairs or so. - 2 long M3 screws. I used 40mm ones, dipped them in epoxy and drove them through the axle of the disc for stability. On one of them the lever is mounted. - 2 5*9*3mm (inside,outside,width) bearings. put them on the disc axle for smooth movement. - some wires and plus to wire and plug - sand paper and an exacto knife. the valve is a tight fit because it has to be tight. sand down and scrape off everything that does not fit perfectly to make it fit. 3d printers are not that precise, at least mine is not. - a few M2 screws. the esp32 is mounted with 4 M2 screws and on one of my valves I had to connect the distance part with M2s to the servo and lever, on the other one i could use M3. servos are different. Thats it basically. instructions go as follows: - print the hull 2 times and the disc one time. - put bearings on disc - put everything together and check that everything fits nicely. If not cut and sand down everything to make it fit - print the servo holder, the esp32 holder, the lever and both distance parts - drive screws through the disc and screw everthing together - solder servo power lines to the power supply and the esp32 as well. connect servo signal pin to the esp32 signal pin you defined in code. - fire everything up, check your router which ip it got and send it http POST close/open commands. servo should move. - now connect servo to lever with the distance part and fine tune the servo movement angle so that valve closes and opens fine And you are good to go, happy valving :D Some remarks: - I had one servo which did a huge jump after a movement when the ESP closed the signal line. I used a 10kOhm resistor between servo signal line and ground to pull the singal down which somewhat helped. it still jumps from time to time but thats not critical for my use case. The clean way to solve this is cutting the power to the servo after movement by using a relay or a transistor - however I did not do that. Or one could use higher quality servos or even locking servos. Or sometimes a pull-up resistor works better. Its basically try&error as well :) - you'll find a FreeCAD project file here with all the components to modify and make your own stuff. - You'll find a Mount STL file which is a simple mount to screw the valve into a hole in the wall. simply screw the mount onto a 160mm hole, put the valve in and tape them together with aluminum tape or gorilla tape or glue them together with epoxy or whatever. - You'll find an adapter STL file to mount a 160mm tube onto a wall with a hole of a european standard brick size. - Printing: I printed everything in 0.25mm layer height and used ASA filament because my use case has some higher temps. UPDATE 2021-07-30: One of my valves had a serious jerk issue. I used a ver powerful servo and its random jerk movements made the screw connection between disc and lever loose. I added a relay and there are 0 jerk issues now. Updated code is in file airvent_with_relay.ino. Its expects a relay on pin 14. wire relay to control the servo power line. The code powers up the servo for a second after PWM is set up on every movement. This way the servo sees clean pwm only and jerking is gone.