機械手：低價位的3D印表機如何幫一個五歲的孩童建構一個義肢
Robohand: How cheap 3D printers built a replacement hand for a five-year old boy
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| Liam's的機械手，由美國的 Ivan Owen 與人在南非的 Richard Van As 合作，並MakerBot 協助 3D printer 製造 Liam's Robohand, the product of a collaboration between Ivan Owen in Bellingham, Washington and Richard Van As in South Africa - and produced on a MakerBot 3D printer. |
不久之前，Liam還是個沒有右手手指的孩子。這位南非的五歲孩童，伴隨著罕見疾病羊膜帶綜合症候群（Amniotic Band Syndrome）出生，這種病症導致他在胎兒時期發育畸形。但是自從去年十一月，Liam 開始嘗試使用一系列的義肢（由兩個居住在地球兩端的人所設計，並由開源的3D列印技術）。
Not too long ago, Liam had no fingers on his right hand. The South African five-year old was born with Amniotic Band Syndrome, which causes amputation of digits before birth. But since November, Liam has been using a series of prosthetic hands designed by two men living on opposite sides of the planet, using open source software and 3D-printing technology.
這兩個人，Ivan Owen 住在美國華盛頓州的 Bellingham， 而 Richard Van As 住在南非，他們在MakerBot's Thingiverse 網站上發表了 Robohand 這款設計，一個可以被自由下載、供人自行3D列印的機械手義肢。他們有意的將這個設計公布在開放的社群裡，藉此希望更多無法負擔昂貴義肢費用（超過上萬美金）的人，同樣可以受惠。
Now, those two men—Ivan Owen in Bellingham, Washington and Richard Van As in South Africa—have published the design for Robohand, the mechanical hand prosthesis, on MakerBot's Thingiverse site as a digital file that can be used to produce its parts in a 3D printer. They've intentionally made the design public domain in the hopes that others around the world who don't have access to expensive commercial prosthetics (which can cost tens of thousands of dollars) can benefit from it.
Liam與他的3D printed義肢相處的第三天。
Liam, on his third day with his completed Robohand.
這個計畫始於Owen於2011年為了參加科技大會所設計的一個機械手。他平日在學校工作，但是他在家中會創作一些奇怪的裝置。當一段由Owen展示他所設計的特大號機械手影片，如病毒般擴散開來的時候，Van As 先生留意到了這個事情－一個因為木工機械事故而失去右手四隻手指的人。Van As 被告知過，要安裝像是 X-Finger 這樣的義肢，每一個訂製手指的要價只少一萬美元，所以他打算利用他的工作室來設計專屬於自己的義肢。
The project began with a mechanical hand Owen made for a science fiction convention in 2011. He works for a school supply business during the day, but he also works from home creating special effects. When a video of Owen demonstrating the oversized hand went viral, it got the attention of Van As, who had lost most of four fingers on his right hand in a woodworking accident. Van As had been told that prosthetic fingers, such as the X-Finger, would cost him at least $10,000 per finger replaced, so he set about in his workshop trying to design his own.
Owen設計的裝置機械手原型。
van Owen's original costume mechanical hand.
單一手指就要價上萬美金的 X-Finger。
Van As 先生和 Owen 主動聯繫，他們倆個開始一系列的長距離合作，並將他們的資料整理在他們的BLOG上（該網站已停止更新，並連結到FACEBOOK頁面上）。Van As 最初寄了一個以他自己的手為樣本的塑膠手給 Owen，讓他去設計。起初，Owen 必須實質上的將設計的原型寄回去給 Van As 先生－這是一個費時又昂貴的過程。
Van As contacted Owen, and the two started collaborating long-distance and documenting the project on their blog, Coming up Short handed. Van As first sent Owen a plastic cast of his hand to use as a reference for design work. Initially, Owen had to physically ship Van As prototypes—a process that was expensive and added weeks to each iteration of their effort.
去年十一月，這兩個人決定碰一次面。我們最初的計畫是，在十一月的時定案、打磨、並強化那款為Rich量身訂做的義肢。Owen 在受 Ars 網頁採訪時這麼說。但是之後 Van As 先生收到一封由Liam母親寄來的電子郵件，她透過了網站看到了他們進行中的案子。＂當 Rich 被 Yolandi 女士（Liam的母親）聯繫上時，我們決定決定跑一趟並幫Liam做一個設計的原型。我們只有三天半的時間，那是一場嚴拒的挑戰，但是我們認定在那個時空下，那是一件絕對要做的事情。＂
Last November, the two prepared to meet for the first time. "Our initial plan for the trip in November was to finalize and polish and improve the prosthesis we had designed for Rich," Owen told Ars in an interview. But then Van As got an e-mail from Liam's mother after she discovered the project online. "When he was contacted by (Liam's mother) Yolandi, we decided we would have a go at trying to build an initial prototype for Liam in the space of time that I was there as well. We only had 3 and a half days, so, you know, it was an arduous task, but it was something we felt we should definitely do while we were in the same place at the same time."
當Owen離開的時候，Liam已經拿到了了他的機械手原型，但是這仍需要一番修改。這整個流程因為一件事的介入而加速了。MakerBot 公司在一月中的時候贊助了兩台Replicator 2 3D printer，他們兩個人一人一台，讓他們能夠快速反覆生產他們的設計。＂我實在不是很理解3D printing，直到不久之前....＂Owen這樣說道。我和 Rich 對於這工具是如此的實用而感到驚訝，甚至是用來製造功能性的組件。它以令人難以置信的速度推進了我們所能做的事情。
When Owen left, Liam had his first prototype hand, but it still needed some work. That work accelerated when MakerBot donated two Replicator 2 printers to the project in mid-January—one for Owen and one for Van As—allowing them to rapidly iterate their designs. "I actually didn't really know much about 3D printing until not too long ago," Owen said. Rich and I have been amazed at how useful it is, even for producing functional parts. It's been an incredible boost to the speed with which we can do this."
Liam使用他的機械手（私人影片已下架）
Owen使用了OpenSCAD －一款開源的電腦輔助設計軟體－來完成大部分的3D printed元件設計。OpenSCAD 並不是一款即時互動介面式的操作工具；相反的，設計必須透過程式碼（scripting）的方式被創建。Owen因為有programming的基礎，所以自學的方式學習怎麼去使用這套軟體來生產他的設計。
Owen has done most of the design work for 3D printed components using OpenSCAD—an open-source 3D computer-aided design modeling program. OpenSCAD isn't an interactive tool; rather, designs are created in a scripting language. Owen, who has a background in programming, taught himself how to use the software to produce the designs.
OpenSCAD 生成的 Robohand 檔案相當的小，檔案大小在 2MB 以內，因此他們可以輕易的讓兩者透過電子信件傳遞。＂有幾次我和 Rich 在差不多的時候醒來，當我寄一個檔案給他，他把檔案列印出來，然後隨即給我一些建議。在約莫15-20分鐘內，我可以再回傳一個修正的版本給他。這種方式很像是我們就坐在彼此的旁邊一樣；整個流程從兩個禮拜縮短至兩分鐘。＂
The OpenSCAD files for Robohand are relatively small—under 2 megabytes—so they can easily be pushed back and forth between Owen and Van As by e-mail. "There have been times Rich and I have been awake at the same time," Owen said, "and I e-mail him a file, and he prints it out, and can send me feedback. And then within 15 to 20 minutes, I can send him a modified version. It's made it a lot more like working right next to each other. Turnaround has gone from two weeks to two minutes."
就在這周稍早，Liam 拿到了由 MakerBot 所製作的最後的版本。由 PLA 塑膠樹酯所製作的義肢在結構性上足以負擔每日的使用。Owen說他們嘗試了填充的百分比－一種參數可以控制物件實心的比率。從數次的測試之後，這隻機械義肢的強度已經達到與真實手臂相同的程度。這同時意味著，隨著 Liam 的成長，這款設計只需要放大並重新列印即可供他使用。當 Liam 成長完全不再發育之後，他的機械義肢就可以用金屬來製作。
Earlier this week, Liam received a finalized working version of the hand, printed on the MakerBot. The PLA plastic resin used by the MakerBot machine is strong enough to be used day to day, Owen said. We've found we can control the in-fill percentage—the ratio of plastic to air in the part," he said. "So actually, from the experiments we've done, the force to break the plastic exceeds the strength of the human hand." It also means that, as Liam grows, the design can just be scaled up and reprinted for him; when he's fully grown, the hand could be metal fabricated.
從一開始，這個計劃就打算要開放原始設計，Owen 說 Rich 和他都很開心有這個機會去做這件事。我們不只是找到了設計的夥伴，但也有志一同的覺得有些事情不該被商業化－這些事情是需要而不是想要－。這兩位將計畫去長期發展這個設計，因為實踐的門檻不用太高而且這將會更輕易的被生產，並使得全球的需求者受益。＂不過如果有誰可以利用這個設計在機器義肢上，我們很樂意和他們合作＂Owen 先生補充。
From the beginning, the project was intended to be open-sourced, Owen said. "Rich and I have been very happy to have the opportunity to do this," he explained. "Not only did we find a design partner, but we're kindred spirits in that we're both frustrated by the fact that there are some things that just shouldn't be commercialized—they're needs instead of wants—that are." The pair plan to continue to develop the design as a mechanical prosthesis in the long term because it is low-tech and could be more easily produced and supported around the world. "But if there is somebody who can utilize the design for a robotic prosthesis, we'd be excited to work with them," Owen added.
Owen 先生也希望他的機械手能夠為那些因戰事失去指節的退伍軍人們（位於國防部與退伍軍人事務部）。我住在離西雅圖不遠的地方，而Joint Base Lewis McChord基地就在附近。＂我想和駐基地的治療師談一談，如果他們有經費可以採購一台3D printer，他們就可以用這麼方式來進行－而整體的生產將會因此下降，因為老兵們不必再為專利權使用費（royalties）付出高額的成本＂Owen 先生說道。
Owen also hopes to get his hand into the hands of the Defense Department and Department of Veterans Affairs to help veterans who have lost digits or hands. "I live not too far from Seattle, and [we] have Joint Base Lewis McChord near us," he said. "I would like to talk to on-base occupational therapists. If they have the funding to get a 3D printer, they could work with this—and the cost to produce them for each veteran is brought down because they don't have to pay royalties."
