Baring ring with holl 3D cad

1. polyline command view sw isometric 
2. start polyline type 10 enter type 4 enter type 10 enter type 4 enter 
3. f enter r enter 2 enter uper ke dono kono per click 
4. 10 wali line jise humne radius nahi diya hai uske midpoint se ekline
5. 10 enter aur iske end point se 6 line left 6 ki line right 
6. revolve command 10x4 all enter and front right left 6 wali line and enter 
7. one rod 5mm ki lene ke liye circle command type 2.5 enter 
8. and extrude 10 enter 
9. array select rod and select pickpoint center click 
10. total numbers of item 10 type ok
11. subtract command select ring and enter select rod enter