岩手県面岸箕から Omogishi Winnowing Basket in Iwate Prefecture

 

　この図は、面岸箕を三次元形状測定機で計測したものです。赤外線レーザーの反射光からその形状を読み取ったものです。反射光を利用しているので、ミサキやアクドが立ち上がった部分のような尖った部分のデータは取得しにくいのですが、面岸の特徴的なイタミの面の形はほぼ完全に撮れているようです。このデータから直接その形状を測定することができます。
This diagram illustrates a measurement of Omogishi Winnowing Basket with a three-dimensional form tracer. Its forms were read from the reflected light of ultraviolet lasers. Since the reflected light is used, it is difficult to obtain data on sharp parts, such as ones where the edge of the opening at the front of a winnowing basket and the stand-up part on the exact opposite side of the opening at the front of the winnowing basket stand up. But it seems that the forms of the sides of a board-shaped structure made by weaving thin bamboo sticks made of the torn outer skin of thin straight bamboo and skinned Japanese wisteria (a winnowing basket made of board-like material) characteristic of the Omogishi district are captured almost completely. The forms can be directly measured from this data.

この図ではアクドのあたりを測定している様子が伺えます

This diagram illustrates that the part around the stand-up part on the exact opposite side of the opening at the front of the winnowing basket is being measured.

　表面の凹凸までものデータは大変重くなるので、ここでは、この面岸の面の形の面白さを自由な視点で見られるように、かなり画像データを軽くした３Dデータ（obj）をリンクしておきます。形の特徴（曲面の構成）に注目しているので、テクスチャ情報は外してあります。この３DデータはOSによらずフリーのPoly(3Dビューアー)で開くことができます。参考までにSTLデータへのリンクもここに貼っておきます。一例として、最近のWindows10の標準設定らしい3Dモデルビューアーで開くと、
Data even on the concave and convex structures of the surface is so heavy that I set up a link to three-dimensional data whose image data was made fairly light so that you can see how interesting the forms of the sides of Omogishi Winnowing Basket are from a free point of view. Because I focus on the characteristics of forms (the structure of the curved surface), I ruled out texture information. This three-dimensional data can be opened by free STL File Viewer, whatever the operating system is. For example, if you open the data by 3D Model Viewer, a recent default function of Windows10, you can get these three diagrams.

の感じです。ミサキの付近の曲面の捲り上りもしくは立ち上がり角度をもっての平面は、何かの機能を体現しているようにも見えます。この図からも読み取れるのですが、ミサキの幅が487.2mm（３DCAD内で目視で測定ポイントを決めていますので少し不安ですが）、両アクド付け根の幅が186.5mmで、ほぼミサキがアクドに対して2.5倍の開きをしていることが確認できます。これも大きな特徴と言えます。木積の藤箕では2倍ぐらいでしょうか。
The plane with an angle of the curved surface being lifted up or standing up around the edge of the opening at the front of the winnowing basket appears to embody some function. With the edge of the opening at the front of the winnowing basket 487.2 millimeters wide (I am not completely sure, though, because I decided on measurement points by visual inspection within 3D CAD) and the base of both stand-up parts on the exact opposite side of the opening at the front of the winnowing basket 186.5 millimeters wide, from this diagram, it can be confirmed that the edge of the opening at the front of the winnowing basket is almost 2.5 times more open than the stand-up part on the exact opposite side of the opening at the front of the basket. This can also be said to be a significant feature. This gap is about two times larger with a winnowing basket made of Japanese wisteria’s bark in the Kizumi district in Sosa City, Chiba Prefecture.

　もう一つの特徴としては、これは、お米の選別などの用途ではない箕に共通して見られるのですが、そのサイドビューはとても鋭角です。アクド側とミサキ側でその周辺の曲面性状には大きな違いがありそうです。
For another feature, which is common to winnowing baskets that are used for purposes other than sorting rice, their side view makes a very acute angle. It seems that the property and state of their curved surface are hugely different around the side of the stand-up part on the exact opposite side of the opening at the front of the winnowing basket and the side of the edge of the opening at the front of the winnowing basket.

　さて、面岸箕を再現するために、まずはこの面岸箕の展開図を実際の面岸箕の外形から呼び出してみようと思います。実物を壊すわけにいきませんので，３D計測データから，

Now, to replicate Omogishi Winnowing Basket, I will first create an expanded diagram of this Omogishi Winnowing Basket from its actual outward form. Because I cannot break the real thing, from three-dimensional measurement data,

光造形機によってミニモデルを３Dプリント（造形方向ミスで表面が荒れていますが）し，
I 3D-printed a mini-model by laser beam lithography (the surface became rough due to a mistake in the direction of shaping, though)

それをコピー用紙により包み込み，基準となる箇所にマークを入れ，再度展開することで，
I wrapped this mini-model in copying paper, marked base points and expanded it again.

を得ます。これをベースに，イラストレータなどの作図ソフトでトレースすることで
I got this. By tracing it by drawing software like Illustrator on the basis of this,

 

面岸箕モデルのイタミ型紙 （ここから型紙が入手できます）

を得て、この型紙を画用紙に貼り付け，
I got the paper pattern of a winnowing basket made of board-like material of Omogishi Winnowing Basket model (a paper pattern can be obtained from this) and attached this paper pattern to drawing paper.

 

面岸箕モデルのイタミ
A paper board of Omogishi Winnowing Basket model 

ようやく上の面岸箕もどき用イタミにたどり着きます。このあとは，正方形箕と同様の手順で造形を進めることができますが，面岸箕独特のミサキのハリの強さを再現するためにと思い，幅5mm，厚み2mmの板状の竹ヒゴ２本をウデキとして，片口状態のイタミの縁を外と内から挟み込むように配置すると
I finally arrived at the above winnowing basket made of board-like material for an imitation of Omogishi Winnowing Basket. Following this, you can proceed with the forming process in accordance with the same procedure as a square winnowing basket. But to replicate the firmness of the winnowing basket made of board-like material unique to Omogishi Winnowing Basket, I used two board-like thin bamboo sticks 5 millimeters wide and 2 millimeters thick for the U-shaped frame tying a board-shaped structure made by weaving thin bamboo sticks made of the torn outer skin of thin straight bamboo and skinned Japanese wisteria and arranged the U-shaped frame in a position that sandwiches the edges of the winnowing basket made of board-like material with its edges of the opening at the front open from both inside and outside.

 

面岸箕もどき調整前
An imitation of Omogishi Winnowing Basket before adjustment

上の写真のように，ウデキの強さに比較するとイタミが柔らかく，実際の面岸箕特有の底部の三次元的な曲面の膨らみと，それに反するようなミサキでの帯状の張った平面状の形は再現されていないことがわかります。おそらく，イタミの剛性が不十分であると思われますし、ミサキの両端に強い力がかかっているようです。実物でもこの辺りの補強とも思われる編み込みが見られますので、このウデキの広がり方では、木積の藤箕の同じ部位での力のかかり具わいとは異なるものがあるようにも思えます。木積の藤箕の柔軟さと比較すると、何か、強烈に強く硬いものを感じます。
As illustrated by the above picture, the winnowing basket made of board-like material is soft compared with the strength of the board-curved structure formed forcibly by the U-shaped frame made by weaving thin bamboo sticks made of the torn outer skin of thin straight bamboo and skinned Japanese wisteria, and the swelling of the three-dimensional curved surface at the bottom unique to real Omogishi Winnowing Basket and a belt-shaped plane form at the edge of the opening at the front of the winnowing basket that makes a stark contrast to it were not reproduced. It seems that the rigidity of the winnowing basket made of board-like material is insufficient and a strong force works on both edges of the opening at the front of the winnowing basket. Since weavings seemingly for reinforcing this part can be seen with the real thing as well, it seems that this fact that the U-shaped frame spreads this way shows that a force works on the same part of the winnowing basket in the Kizumi district in a different way. Compared with how supple the winnowing basket in the Kizumi district, is, I somewhat feel that the winnowing basket made of board-like material is intensely strong and hard.

 

面岸箕光造形モデルと箕もどき初期形状
A laser beam lithography model of Omogishi Winnowing Basket and the initial shape of an imitation of winnowing basket  

ここまでの試行錯誤を通して見えてくることは，イタミの部分的な剛性不足があることは間違いがないようです。底部中央辺りの膨らみやアクド下後部の膨らみ具合を実形に近い光造形モデルのものと比較すると、紙製のものはどうしても局所的な曲げに対する剛性が低く、平面状にある傾向があり、そのことが、この箕と箕もどきとの決定的な雰囲気の差異を生んでいるように見えます。
The trial and error I have gone through so far seems to show that undoubtedly, the rigidity of the winnowing basket made of board-like material is partially insufficient. The comparison between the swelling around the center at the bottom and at the back part on the bottom of the stand-up part on the exact opposite side of the opening at the front of the winnowing basket and that of the laser beam lithography model close to the real shape seems to show that the paper-made winnowing basket inevitably tends to be less rigid to partial bending and be planar, which makes a real winnowing basket and an imitation of winnowing basket critically different in atmosphere.

　そこで，応急処置的に、引き伸ばしたセロハンテープをイタミ表面に伸ばしたまま貼り付け，その面を局所的に縮ませる力を与え，曲面形状制御を試みましたところ
In response to this situation, for an emergency measure, I tried to control the shape of the curved surface by attaching a lengthened Scotch tape to the surface of the winnowing basket made of board-like material and applying force to partially shorten the part.

セロハンテームで曲面剛性制御された面岸箕もどき 
An imitation of Omogishi Winnowing Basket with the rigidity of its curved surface under control by Scotch tape

実際の形状に近づく傾向にあることが確認できました。このことよりも，このサイズ感においては，このイタミとしての素材は、このウデキとしての素材に対しては剛性不足であることが明確になったので，次なるイタミの剛性アップの工夫を探してみたいと考えています。

As a result, I was able to confirm that the controlled shape tends to get more similar to the real shape. In addition, because it became clear that this material as a winnowing basket made of board-like material is insufficiently rigid to the material as a frame U-shaped frame tying a board-shaped structure made by weaving thin bamboo sticks made of the torn outer skin of thin straight bamboo and skinned Japanese wisteria in terms of this size, I will seek for the next better way to enhance the rigidity of the winnowing basket made of board-like material.

　さっそく作ってみました。今度はミサキ付近のごわごわ感（面剛性）の再現を目論で、グラスファイバー製アミドの余りを高強度接着剤で貼り付け、要所要所を引きちぎれない程度に伸ばしたセロハンテープを添わして部分的に凹凸を生み、ウデキにはプラ棒をつかうことで、ウデキが自然状態にもどろうとするときの力の影響力をやや下げるとともに、それがイタミを把持する方向をできるだけ無理のないようになるように配慮してみましたが、それでもどこか雰囲気が異なります。イタミ中央付近のへこみと、そこからミサキ両サイドへのぼる曲面のつながり方が顕著に異なり、面岸箕の実形が示す三次曲面とは異なるものがあります。
Then, I gave it a try. Looking to replicate a sense of stiffness (plane rigidity) around the edge of the opening at the front of the winnowing basket this time, I attached the excess part of glass fiber window screen with an ultra-strong adhesive and created a rough surface with a Scotch tape whose important points I lengthened to the point that they would not be torn off. By using a round plastic stick for the U-shaped frame tying a board-shaped structure made by weaving thin bamboo sticks made of the torn outer skin of thin straight bamboo and skinned Japanese wisteria, I slightly reduced the influence of the force at work when the U-shaped frame reverts to its natural state to see to it that the direction in which it holds the winnowing basket made of board-like material would be made as natural as possible. In spite of this effort, I find a little difference in atmosphere. I see a noticeable difference in the dent around the center of the winnowing basket made of board-like material and its leading to the curved surface that ascends to both sides of the edge of the opening at the front of the winnowing basket from there. They are different from the three-dimensional curved surface formed by the real shape of Omogishi Winnowing Basket.

やはりまだ不十分です。根本的な問題は何なのでしょうか。ここまで来ると、実際の面岸箕を再度触らせてもらい、振らせてもらわなければなりません。どうも木積の藤箕のように素直な弾性曲線で構成されているとは言い難いところがあります。そこにこの形特有の魅力があるのかもしれません。一回ここで止めて、別の箕のかたちを探りながら、気に留めておきたいと思います。

These diagrams show that my efforts are still insufficient again. What is a fundamental problem? Though I have come this far, I have to get another opportunity to touch the real thing of Omogishi Winnowing Basket with my hands again and swing it. I have the impression that it is difficult to say that it is constructed by a simple elastic curve like the winnowing basket made of Japanese wisteria’s bark in the Kizumi district. That may represent an attraction unique to this form. I will stop here for now and keep it in mind seeking for different forms of winnowing basket.