In this tutorial i design a simple Gear. Just the basics. I hope it is ok. If you have any questions feel free to ask.
1. Open SW, then create a new document and choose Front Plane and sketch
2. Draw a 3x circule from the centre for construction. Dimeters: 100mm, 85mm and 76mm.
3. Select Centerline and drav 4 lines, like in the photo.
4. Select a 3 PointArc and draw a line from the 2. to the 3. line.
5. Select a Line and draw a line frome 3PointArc to the first circule and make Tangent!
6. Select Centerpoint Arc and draw from the center to the 1.circul where the 1.construcion line is and to the 2.one. In the photo you se this as a green line.
7. Select Centerpoint Arc and do the same but from the 3.to the 4. construction line
8. Draw a line from the center to the first circul.
9. Select Mirror Entities and first choose the entities to mirror and step dwo Mirror about and choose the line (4.construction line). and OK
10. Close the Sketch
11. Features and select Extruded Boss. Depth 10 mm and OK.
12. Go wher you have Linear Pattern and CHOOSE Circular Pattern. no.of instances: 20 and ok
13. that is it :)