This large gear was designed in TinkerCAD and has about 20 teeth. It has a square hole in the middle to fit many attachments. The small gear is designed in the same way, but instead of a square hole, it is a circular hole. You can find the link to these gears on TinkerCAD in the How I Designed This section.

Creality

Ender 3

Yes

Doesn't Matter

Normal or Best

Any Infill

You can print this on any printer, and there is no specified infill or color.

I used TinkerCAD as a main designing app, and I created the gear by using different shapes and sizes of shaped to create a gear with a square in the middle of the gear. The small gear is designed in the same way, but with a cylindrical hole in the middle of the gear.
TinkerCAD Links:
https://www.tinkercad.com/things/hoWnWmuImqD-large-gear
https://www.tinkercad.com/things/0CiqM1U8wwZ-small-gear