Vacation Pet Feeder from Recycled Materials Using Arduino • Tech Projects

If you are a pet owner, going on vacation can be stressful. Usually, you need a friend or neighbor to come over every day and feed your pets. However, by enslaving robots you can keep your pet happy and enjoy a stress-free holiday. To save money and learn something new, I decided to make my pet feeder out of recycled materials like cardboard and glue sticks. Cardboard is great for rapid prototyping.

I have entered the pet feeder into the Make It Real Challenge because it relies on 3D modelling software for a rapid prototype design. I made this instructable especially for the contest after writing the original article for wonderhowto.com. As much as I love cardboard, I could prototype more precise designs with a 3D printer and build up my design skills for rocketry and robotics mechanisms. Please rate, vote and comment to help make my cardboard dreams a plastic reality!

Materials

Glue stick
Cardboard
Scissors
Hot glue
Continuous rotation servo
Arduino board

Step 1:

We will be using the glue stick case as a linear actuator. To attach it to our servo, we must first get rid of the glue. Remove the glue from the tube and pry it off of the inner plastic slide. This can get messy so be careful! Remove the circular cap at the base of the glue and set it aside.

Step 2: Make Actuator Arm

The rotational motion exerted at the bottom of a glue stick causes the glue to travel up a spiral rod and out the end of the cap. We are replacing the glue with a brass tube to make it sturdy enough to handle all that pet food.

1. Hot glue the tube into the small plastic cup from inside the glue stick. The hollow tube will fit neatly around the inner corkscrew of the glue stick.

2. Make four notches in the handle of the glue stick and fit them over the servo horn. Use hot glue to secure the connection. It is important to make sure the glue dries while the servo and glue stick are perfectly aligned. This will prevent wobbling.

Step 3: Make an Enclosure

I designed my first ever google sketch up model just for this project. Seeing a model in 3D makes it easy to evaluate your design before you build. While the setup is very simple, I think the 3D model helps in understanding the linear actuator. Open the attached google sketch up file to see the pet feeder sketch up.

petfeed.skp478 KB

Step 4: Attach Arm to Base

There are many methods you can use to attach the moving platform to the actuator arm. I hot glued a circle of cardboard to the arm and then glued the platform onto the circle. You can also use screws and balsa wood if you want a more secure connection.

1. Make the platform slightly smaller than your enclosure to allow the platform to slide inside the box. Recycled Materials circuit

2. Glue the bottom of the servo to a cardboard base.

3. Push the actuator arm into the box and seal the bottom with hot glue or tape.

Step 5: Adjust Platform and Cut Exit Chute

Mark where the maximum and minimum heights of the platform are. Cut a circular hole in the side of the enclosure in between the two levels. This is where the pet food will spill from. Set the platform to the maximum height, entirely closing off the chute. Gently pour the pet food until it fills the upper chamber of the feeder.

Step 6: Circuit

Our circuit is very simple. Connect the red servo wire to 5 volts on the Arduino. Connect the black wire to Arduino ground. Connect the white wire to Arduino pin 10. That’s it!