Thursday, July 26, 2012

HOW IT WORKS: FLETCHER CAPSTAN TABLE

by Ahmed Abbas Momin

The Fletcher Capstan Table is named after designer Fletcher David, its a kind of table which automatically expands from a small size to a larger one.
It is a round table capable of doubling its seating capacity and, in process of expanding it remains truly circular. The original idea for a table of this type was designed in the nineteenth century by a man named Robert Jupe, 1835. It was called as Jupe’s table Youtube Video initially round, and had an ingenious geometry and a similarly ingenious method of making it expand radially, changing from a small size to a table of larger diameter. However, Jupe’s tables could not store their own expansion leaves, were not truly round in every stage, and were slow and laborious to operate. The Fletcher geometry is similar in concept, but different in terms of expansion leaves. It’s minor changes, according to the species of timber used, as the table expands from small to large, and shrinks vice versa.

The top surfaces is made up of six pie shaped planks (figure 1), and an outer skirt in the manner of a drum table . Below this first layer (figure 5) there consist two more layers of planks , the second is made up of six arrow shaped planks (figure 5) and, under that, a large star shaped leaf. Below all of this lies the rotating mechanism  and pushing mechanism, constructed with the combination of hard anodised aluminium and stainless steel. Table planks are made from aluminium honeycomb cored composite for absolute integrity and rigidity. The whole assembly is supported on a base of varying design.
The table can operate manually by rotation of the entire top, or electrically from a pocket sized remote control transmitting unit. All tables, be they manual or electronic, rotate through 120 degrees as they operate, and electronic tables can easily be converted to manual.



The table transforms from a small circular wooden table into a larger diameter by rotating its side while the extra wooden pieces (2nd layer planks) underneath the furniture in its small state and then automatically raises them up and adds them to the whole circular form of the table as you rotate and transform the furniture into a larger piece.


Each section is connected to an underlying frame structure, such that when the table top is rotated, the sections move radially outward, increasing the effective size of the table top . Once the table top has been rotated the left over space is filled by 2nd layer of planks which are pushed up during the process of rotating.


A method for manufacturing
Starting with table support structure and defining a central axis; mounting a table top over the table support structure such that the table top is rotatable around the central axis between a first angular position and a second angular position relative to the table support structure, wherein the table top comprises a guide plate having a plurality of guide slots and a plurality of separate table top sections disposed over a top surface of said guide plate, each table top section being movable radially along a respective one of the plurality of guide slots between a first radial position and a second radial position when the table top is rotated between the first and second angular positions relative to the table supporting structure; and providing a plurality of support elements between the guide plate and the table support structure, the support elements being arranged to support the guide plate relative to the table support structure, wherein the support elements are mounted on a portion of the table support structure, whereby the table top is arranged to rotate relative to the support elements
 Another video of the table





9 comments:

  1. Hello

    At first I have to say that what a awsome work you have done. At the moment I saw the video of this table I knew that I have to build one and since that I have been looking for anykind of technical drawings and design for the mechanism.

    I was wondering maybe you would have more detailed drawings that I could use. For example in the last figure I cant see use for all the rings, what is their function. All I could figure they are for raising the center piece but for that I can figure better methods.

    Also I was wondering that what is you solution for the size of the plates. In this particularly I am wondering about the outside arc. If you take a segment of perfectly round circle and move it outwards from the center to form a new bigger circle, then the out side arc of that segment is not fitting for forming a perfectly round circle of bigger diameter.

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  2. Look at the table again when it is in its smaller form before the skirt raises. It is not perfectly circular as the diameter of the larger form circle forms the edges. The Fletcher Capstan table has an outer ring (the skirt) that raises and lowers. When the table is in its smaller form with the imperfect circle then the skirt raises and wraps the imperfect circle with the perfectly circular but slightly larger diameter ring. This ring's inner diameter is the same shape as the imperfect circle of the smaller form of the table. The outer diameter is the perfect circle. Hope that helps.

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  3. This is good stuff, but i knew all of this from simply watching a video of the table in action. I am looking for details as to how the mechanism actually works, not just what it does. Please help.

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  4. Hi, unfortunately we have to tell, that we are not having any additional infos about the table, we ask the students to pick a topic and explain it, sometimes its more detailed sometimes not, in this case, the infos were collected from the videos available, so unfortunately no more infos in details. Sorry about that .

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  5. Thanks for your quick reply. i am currently tinkering with an idea i have to make it work, basically like a camera shutter with the leaves sticking out instead of in, i am hoping to make the center star leaf raise and lower with a basic screwing mechanism. if you have any more ideas i would love the help.

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  6. This was just a quick idea that I threw together as a project for college. I do not know what the mechanism used for the Fletcher table is. So i tried to come up with my own. See the inscrutables page where this is found:
    http://www.instructables.com/community/Help-me-design-a-table-like-this/?comments=all#CPIVT3FHCV8X5Y4

    This was more of a conceptual idea than anything.

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  7. https://www.dropbox.com/sh/bxaqa008rwzjrrx/cb1mgFPR52#/

    here u can download all the project

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  8. Nice tips. Thank you for sharing this information.
    Plywood Manufacturer in India

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