Projects for my cat and More

Demonstration Video

Overview

Due to a dietary restriction my cat only eats wet food. The typical automated cat food feeder only works with dry pellets. The goal of this project is to create a feeder which can open and dispense a Costco wet food can.

The Costco wet food cans are a unique hexagonal shape with a soft top tab. For this reason an existing automatic can opener cannot easily be used.

Design

The opener uses a geared stepper motor to drive two rack and pinions which are connected to a cartridge that holds the can. The can’s tab has to be manually screwed into the drive shaft going through both pinions (see pic below). The nice thing about this design is that with a single motor it combines rotational motion to pull back the tab with translational motion that pushes the can forward.

CAD

I used Fusion 360 to design the feeder such that each part can be 3D printed. The model can be viewed in a web browser here and can be downloaded with the link below:

The 3D printed parts are designed to be added to 2020 aluminum extrusions which are used as the frame. I added clear acrylic around the frame for safety to prevent my cat from reaching the gears.

Parts List

• Nema 17 Stepper Motor with 5:1 Planetary Gearbox
• Stepper Motor Driver TB6600
• 2020 Aluminum Extrusion
• 2020 Aluminum Extrusion Corner Brackets
• Arduino Uno
• Power supply

Next Steps

In my next blog post I will set up the electronics to allow me to schedule the machine to start opening the can. I’m thinking of using a Raspberry Pi and adding a camera so I can stream the footage remotely. I will also create a power distribution board because currently I am using a variable power supply.