Set sweep is already a very mature design. When I first got the project, I felt that I didn't think it was a broom. (Simple) I didn't think about asking the customer 2-3 times of plan and modification (vomiting blood). Finally, I decided on this one (the brush was laughed at). Then I didn't know that a set sweep had so many details until the structural design. Structural designers without experience in this field had a high probability of problems