Step 1: Sketch a 17mm Diameter Circle on the Front Plane
Step 2: Create a Vertical Centerline at the Top of the Circle, Draw Half of a Tooth and Use "Mirror Entities" to Mirror About the Centerline
Step 3: Use "Circular Pattern" to Create 21 Identical Teeth Around the Gear and Use "trim Entities" to Trim the Circle
Step 4: Extrude the Gear by 4mm Using "Extrude Boss"
Step 5: Use "Hole Wizard" to Create and M2 Counterbore Hole in the Center of the Gear
Step 6: History Tree
Make it Glow Contest 2018