Reinforcement ribs and spokes are used to reinforce thin walls and avoid thick sections. In addition to increasing the strength of wall thickness, it can also improve material flow and limit distortion. The thickness of reinforcing ribs shall not exceed the thickness of adjacent walls. More reinforcement ribs should be added if the structure needed. Figure 1 shows the recommended rib reinforcement ratio. Fig. 2 shows how to use them and coring holes to reduce weight while maintaining the functional strength of parts.