在开始制作的这个模型前，我从苹果树上收集了许多弯曲的木料。
Before starting construction of this model I collected many compass timbers from Aplle wood.
懂金属学的人告诉我，当你反复弯曲一块金属的时候，它就开始疲劳了。
People with a better knowledge of metallurgy than I have, tell me that once you start to flex a piece of brass backwards and forwards, you start to fatigue it.
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