The main functions in the Arduino program is working! I have spent the last month programming the various functions while parts for the BottleBot are printing. Functions like moving the conveyor belt, positioning of bottles, as well as filling them seems to work now. At least in theory, using the serial monitor.

The conveyor belt is now assembled and working. I have run the motor and the belt is capable of transporting full bottles all the way through. And the robot is coming together. At the moment the lower part of the robot and the "bottle positioning arm" design needs more work. The servo I'm currently using to push two bottles into position, a Futaba S3003, doesn't have enough torque. I'm using a MG995 servo to control the "heavy" robot arm with the solenoids and that servo model works fine and will also be used for positioning the bottles.

The above picture shows a bottle just as the conveyor belt stops. The yellow push bar will now push the bottle into the bent rail on the other side, and the bottle is in the correct position for the filling arm to hit the bottle opening and open the valve.

Here the yellow push bar have pushed the bottle into position. When the push bar is released the bottles are free to continue down the belt.

I'm still not satisfied with the push force and need to order a better servo.