機械工程學系畢業生?

Recently, I felt so frustrated of being a student graduated from dep. of mechanical engineering. Things went like that: my father hoped my brother and I design a mechanism for automatically opening and closing up two plates which are pinned together at the edges of each one, just like the lid of a copy-machine and the glass matches with it. But the differences between these two are the accuracy and the weight of the lid. This mechanism has to ensure the relative position of two plates while closed can only change within several micro-meters after thousands times of movement. And the weight of the lid plate is about 25kg.

考完gre後的這三周，真是讓我相當挫折，覺得我實在是稱不上一個從機械系畢業的學生。事情是這樣子的：我爸在過年左右就要我和我哥(當時我哥人不在台灣)幫他設計一個為二塊平板自動開合的機構，二塊平板的結合方式有點類似影印機的蓋子和它的板璃，不過差別在於我爸需要的是這二塊板子在數千次的開合後，閉上後的相對位置不能跑掉，第二則是上蓋的重量有25公斤重。

What let me feel down is that, thought this should be sort of simple mechanism in actual world which is only concerned with static mechanics, but however, it haunted me for these three weeks. I even could not guarantee that the analysis of FBD(free body diagram) I drew is correct, because the actual mechanism which assembled by parts made as my design doesn't work! Punch! Reviewed former design, modified those parts, and tried again, but still failed. Punched again.

最讓我挫折的是，這種感覺上在這真實情況中應該算是簡單級的設計，因為它只牽涉到最基本的靜力學而已。但我卻不敢保証自己想出來的FBD圖是對的，因為真正把機構的零件製造出來組裝起來後，卻沒辦法達到開合。重新審視設計的過程，修改設計，再把零件送去修改。再回來組裝後，卻仍然不行，才又發現修改的也是錯的。

Now I totally redesign the mechanism, and hope it will work.

Actual world is always more terrible and complex than what we learned in textbook.

現在是完全重來了。重新想其他方式。
有機會再把相關的圖面貼上來。

by the way, the gear pic about this article has nothing about my design. XD