Hardware

We searched around online, and found several DIY cat feeders that used an auger to dispense food (most notably, this one and this one). We used an auger from a KitchenAid food grinder attachment. (The auger can be purchased separately from a variety of sources.)

To turn the auger, we coupled it to a small motor (continuous rotation servo). The challenge here was to find a coupler that would accomodate the KitchenAid auger, since they use a proprietary square 11mm shaft. After trying (and failing) to find a commercially available coupler, we made our own design and had a friend print it using a 3D printer.

The auger was a perfect fit for a 1-1/2” PVC T-joint pipe, which we used to house the auger and channel the food into the screw. However, in version 1 of this feeder, food would jam in the neck of the T-joint PVC pipe and it didn’t dispense reliably. After several weeks of frustration, we cut off the neck of the pipe to create a wider opening and expose more of the screw. In hindsight, we could’ve just used a PVC pipe, and cut out a large square hole on the top. The main lesson we learned here is to expose as much of the auger as possible to the food reservoir above it.

A PVC bushing inserted into the back of the pipe provided a perfect support for the shaft of the auger. Everything was secured with screws, and attached to a wood base.

Although we spent quite a bit of time configuring and optimizing the auger set-up, it is important to note that all subsequent steps are only limited by your creativity and carpentry skills. We've chosen to use a large-ish wooden box because we like its heft (good for preventing Barley from tipping it over) and the relative ease with which we could manipulate it (for a long time, our living room was covered in saw dust from our various attempts at building the feeder).

In the Software section, you will find more detailed information on the servo settings for turning the auger -- through trial and error with our particular food brand, we found that turning it forward and backward a couple of times during each feed cycle yielded the appropriate amount of food without jamming.

We used an old flower planter box that we found at a thrift store to house the entire feeder assembly. It had a conveniently placed hole on one side that fit the PVC pipe with the auger. The servo was attached on the opposite side of the box.

To channel food to the auger, we constructed a chute with slanted sides. Because we wanted easy access to the servo/auger in case of potential repairs, the chute was made from parts that came apart easily (i.e. no screws or glue). The chute consists of two side parts, and one back part, all of which angle the food gently down to the auger. Pardon their crude appearance — this project was also the inaugural one for our new jigsaw, so we were just happy to come away from it with all fingers intact.

A removable front panel attaches via hooks and completes the food reservoir. We also made a fabric reservoir liner, which helps protect the wooden chute parts from food crumbs.

The hole through which the auger dispenses food is covered up by a wooden awning, to prevent curious little paws from getting into the auger. The bowl is positioned below the awning, and is held in place by a wire ring from an Ikea Fintorp kitchen caddy.

The top cover seals the feeder with an almost air-tight seal, and also has an attachment for a webcam. The clear box protecting the webcam is a baseball display cube.

We also attached a water bottle to the side of the feeder, since Barley sometimes prefers it to drinking out of his water bowl.