Insert

For Cone, Prism, Sphere, BG Img and Spur gear you first need to select an object which maximum size will determine the size of selected insert type.

Spur gear - if you created a gear and you want to create new one that meshes with this one select the gear and choose spur gear it will switch to pinion option where you set ratio between original gear and new one and app will create proper spur gear for that. The bigger the ratio the smaller new gear (pinion) will be.

Default values for  pressure angle are from 18 to 20 degrees

App can't print that properly unless it is really big gear.