If want to highlight coping or make model, need combination of a variety of norms keel joining together, taller to machining craft to ask, error limits should be controlled in millimeter less than.

• 假如想突出顶部或做造型，则需要多种规格龙骨拼接组合，对加工工艺要求较高，误差范围要控制在毫米以内。