Hey, cool project!
- you can use linear actuators that have the same travel length as the slider in the pictures of your seed drill. Add a rubber element or spring if the length doesn’t match 100%. These linear motor can bend the slider if debris builds up. This one travels 50mm, looks like that is what the slider in your picture moves al well. Heads up only IP 54, you need to protect them from the elements (water etc.). Amazon.ca
- there are some linear motors where you can adjust the end stops (still have some sort of cushion / rubber element)
- build it like suggested in the video.
- us this code: ESP32 Machine board via WiFi increase the relays to 39 and run two relays per section, one inverted one normal.
- or use the regular machine board, add / increase up to 19 relays, these relays trigger the DPDT relays which control the motors.
- You might want to add a main switch that lets you turn the power to the motors off. Once AOG powers down the relays all go low, causing all motors to close (or open) all at once. 19 motors might draw quite some current. This would be the case on your headland as well once you closed them once by one when seeding on an angle. When you start a new row they all need to open at once. I would not expect crazy current draws but 19 motors could sum up to 20 or 30 amp easy if the sliders move light. maybe have a smaller fuse for for each motor so it blows the motor fuse where you have a hard to open or close slider.
Good luck!