You can 3D print the automatic feeder using PLA or PETG. The print files are optimized for PLA.
To set it up, you need to understand basic electrical wiring and be familiar with Arduino.

 I can post the script for operating the feeder here.

In addition to the 3D-printed parts, you will need to purchase the components listed in this BOM:

The images below show all the printed parts.

Use a stepper motor that is no more than 23 mm high. 

The following images show the electronics wiring diagram. Be sure to follow the diagram if you want to use my control script!

The Arduino includes two potentiometers that control the interval between feedings and the amount of feed. The potentiometers are hidden behind the feeder's cover.

This is the analog version controlled by a potentiometer. If there is enough interest, I will release a version with an ESP32 that will control the feeder via a mobile app within a local network.