• 1
    Build Process

    Video

  • 2
    Assembling the Circuits

    To start, you should gather all parts listed above.

    First, we will create the circuit that pumps the soap bottle.

    For this you will need your servo, a builder base, and three MM jumper wires.

    With most 9G servos the wire colors will represent the following:

    Actuator Servo:

    We will now connect the Servo to the Builder Base using the jumper wires as follows:

    If you decided to use the servo timer instead of the LCD to display the time remaining, you will need to add a second servo to the client attached to GP1.

    Timer Servo (Optional)

    Now we can assemble the circuit for our LCD and Distance Sensor. If you follow the diagram below you should only need 4 MF and 6 MM jumper wires, and a bread board.

    Here is wiring guide for the two components:

    Ultrasonic Sensor:

    2x16 LCD:

  • 3
    Building the dispenser (3D printed Case)

    We’ve updated this project with a 3D printed case to house all of the components. You can find the model at the bottom of the page.

    If you do not have access to a 3D printer continue down to “Step2: Building the dispenser (Old Case)” to learn how to build the model without our 3D printed box.

    With this project you have two options to show the time remaining. The first option we’ll show you how to build is the LCD timer, and the Second will be the servo timer.

    To place the LCD timer onto the case you will need your LCD circuit and 2 M3x 20mm bolts.

    Using your M3 Bolts, secure the LCD to the front plate of your project, like so.

    Next, place the client that the LCD is connected to the rear client holder.

    And that’s it for installing the LCD Timer!

    Start by printing out our timer graphic, cutting it out, and gluing it to the front of the case as shown below.

    Next, place your servo and its wires through the rectangular hole in the center of the front plate.

    Next, we will place the actuator servo on the case. Do so as shown below.

    Place the servo in the slot on the left side of the face plate with the servo spline on the top half of the servo. Next, using 2 M3 screws, secure the servo to the base.

    Now, we will place the servo client on the back of the case.

    The client holders are designed to hold the client in place through a snug friction fit, so no velcro or adhesives are needed.

    Next, we affix the distance sensor and its client to the case.

    Simply place the distance sensor into its slot and bend the wires upwards so that there is clearance for the soap bottle. As for the client, place it in the remaining client holder just as we did for the previous client.

    Next, we will place the soap bottle in the case. Simply squeeze the bottle into the center cutout. We sized ours to fit most generic soap bottles, but if yours doesn’t fit in the case you can modify the 3D file to fit yours.

    Now, to complete the assembly of this project we need to attach our dispensing wire to the case and the servo.

    Start by threading your wire through the hole that is adjacent to the distance sensor.

    Then place the wire atop the dispenser nozzle.

    Finally, holding the wire taught, feed the wire through one of the holes in the servo arm and tie it off.

    That’s it! The assembly of this project using the 3D printed case is now complete!