To think about a bench is to think about several people. And several uses. Some people read, others sleep, some sit and some eat. Sometimes it’s just good to be able to do it all. For the IaaCommunity Bench, we decided to keep it simple and keep it working. A table bench. As the section of the bench was predefined to enable the different proposals to connect, we started by defining that the top of the bench would be flat and the bottom would look like… a bench! The editing process begun by creating a cage with the command CageEdit>Select the Bench>BoundingBox> x=15, y=10, z=4. With the Control Points on, we repositioned the points so we could have the form imagined by us. After the form was defined, we needed to close the interior surface using the command Curve> Curve From Objects> Duplicate Edges.  Then to create a surface and finally close the bench, we used the command Loft.

The next step was to use command Contour to create sections of the object in X and Y axis. For that, we created new layers, one for each axe. After creating the “ribs”, we created a new layer called “Intersections”, and used the command “Intersections” to create lines in the intersections between the ribs in X and Y axis. Those lines were used as guidelines to create pipes at the intersections between the ribs.

Using a Grasshopper script we chose ribs on the x-axis, the y-axis and the intersections lines in order to be faster instead of copying and moving each pipe one-by-one manually. After the intersections had been made, we baked the axis individually and grouped each rib by using the TOP view and selecting each line separately.

After we mdke a new layer called DOT, we used the Dot command to name each rib and group it with it’s piece so we would be able to move them around without getting the order of construction lost. We then rotated the ribs so they could be in the same direction. We trimmed each section in order to get the connection edges. Finally we used another script to engrave the numbers and our name in the pieces under a new layer.

To finish the process we deleted the previous layer DOT and drew a rectangle with the dimensions of the wooden board  (1200×2500) under a layer Wood. We manually placed each rib on this plane in order to make the most efficient placement and the less use of materials. Finally we created a layer Cut and renamed all the ribs on that layer. The file was then ready to be exported as a .dxf format.

]]> http://legacy.iaacblog.com/digitalfabrication/2010/11/09/3007/feed/ 0 http://legacy.iaacblog.com/digitalfabrication/2010/11/08/ribbing-process-the-bench/ http://legacy.iaacblog.com/digitalfabrication/2010/11/08/ribbing-process-the-bench/#comments Mon, 08 Nov 2010 14:09:05 +0000 cesarandresbricenogutierrez http://legacy.iaacblog.com/digitalfabrication/?p=2459 Laser Cutted
Team: Javier González R. – Andrés Briceño G.

Viraat

After experimenting with the first exercise -where we have to come up with a Lego brick design, we have involved ourselves into this new assignment, which is to design a small bench and fabricate it using a laser cutter.

During the process we look at different precedents where we learned more about parametric design of furniture.  We took a look at the ‘Parametric Couch’ designed by Seyyed Mohsen Hossainy, the ‘Chick ‘n’ Egg’ Chair designed by Manuel Kretzer of the group CAAD/ETH Zurich.

To carry you through the development of the bench in rhino…

Primarily we began with the curves and arranged the curves in a manner to get the correct curvature and bends.

Secondly, we lofted (loft) the contours to generate the  form, thereafter we contoured (contour) the bench with sections longitudinally and latitudinally.

On generating the contours we created a planar surface (PlanarSrf) for each contour and used the intersect command to get the intersection lines.

A pipe was created about the central axis of each line and projected upward and downward about the mid point of the intersection lines.

The pipes in the upward direction were intersected and trimmed with the latitudinal ribs and likewise the downward pipes with the longitudinal ribs, such that, the groove of the ribs interlock with each other.

The face edges of each surface was duplicated from the Curve<Curve from Objects<Duplicate face border option.

Each curve generated was grouped along with the rib number (to make identification and assembling easier). The Rhinonest plug-in was used to quickly organize the curves on the size of the plywood sheet. The file was then exported to the dxf format for laser printing.

The bench has multiple properties, it does not only can be used as a seating furniture, but also as a tool where students can interact and use it to place cups, cans or bottles, also the lower part is open for storage where backpacks, books, shoes,  and other objects can be placed.

<a href=”http://Viraat“>

The second assignment required decomposing the 3D design of a piece of furniture, into 2D elements to laser cut them as its pieces. It was also important to consider that the model would be part of a fluid whole later on, so it had to respect the limits given for it and the shape of its initial and final faces.

Resuming the design process, it was developed inside the boundaries given and taking advantage of some free space to give it some movement through the invisible cage. Then, the its top was modified by using control points to give it some flatness that would allow it to be useful as a confortable bench.
The result was a dynamic element which provided excellent prospects for successful fabrication as also its integration with the other designs.

With the design already completed, the 3D model was modified to be produced using the laser-cutting machine. The surface of the design was offset and contours were created. Intersecting surfaces were made from these contours and cilinders where placed on them, which were later trimmed to create voids in the elements in order to be able to join the pieces. The intersection slots were made to be 2.8mm wide, creating a snug fit for the mounted panels. Finally, the various pieces needed to be separated and projected, side by side, onto a cplane which had the same dimensions as the wooden panel to be placed in the laser cutter.

Once the 3D design had been translated into the 2D layout, its file was exported to the laser cutter. A 3mm thick wooden plank was cut into the various waffle pieces. The cutting process was closely monitored in order to comply with the necessary safety precautions, such as ensuring that the cut pieces didn’t obstruct the machine while it was still in progress and of course to control a possible fire.

After the pieces were cut successfully and without any incidences, they were assembled to be part of the final product.

The aim of this assignment was to design a bench that would constitute part of a collaborative furniture project and construct a model of 1:2 scale using the waffle structure and a Laser Cut machine. The bench should be designed by transforming a given model in Rhino within a bounding box of 500mm x 500mm x 350mm but keeping the end sections untouched in order to connect with the different benches.

Designing the bench model

As a first step in the design of the bench we exploded the initial model in order to separate the top surface and transform it. In order to do that we rebuilt the surface by putting 10 point counts to both U and V and keeping in mind that this surface is not only going to be the sitting surface of the bench, and therefore it should be comfortable, but also that it should fulfill our aesthetic criteria we activated the control points of the surface and started to move them at will.

We begun by hollowing the arched initial surface so that to create two pits that will consist the main sitting areas (more accurately, one sitting area for two persons), but keeping the back of the bench so that it is more comfortable. Then we moved vertically the control points of the back of the left side of the bench until the borders of the bounding box and we repeated the process horizontally by extruding the right part of the bench until the bounding box and at the same time hollowing the left, so that in one hand it would amplify the waving form and on the other hand it will enlarge the right sitting area and turn it towards the other. Afterwards, with the command Surface, Extrude curve, Along curve, we closed the shape, and by typing Boolean2objects we union the different surfaces. The final result acquired a biomorphic form that serves as a hug, as a nest for the users.

The waffle structure

After completing the form of the bench we started the procedure of the waffle structure system. We used the contour command in both X and Y axis in order to produce sections on the form every 50mm. Then, with the extrude curve command we extruded 50mm the curves of the y axis and due to the fact that the curves on the x axis form loops we used the command offset to offset them also 50mm and we created the surface by typing PlanarSrf.

Afterwards, we selected the ribs from both directions and using Curve Curve from object, Intersection, we intersected them. On each of the intersection curves we created pipes of 2.8mm thickness, we moved them vertically from the end point to the midpoint and then we copied them from the top end to the bottom and putted them in a different layer. Therefore we were able to intersect the different pipes from the according axis of ribs and delete the small part of the intersection by using the split command on each rib and the curve that was created by the intersection. With that procedure we completed the design of the ribs of the waffle structure.

In order to prepare the parts for the Laser cut machine (we used the Epilog Laser cut machine of the Fab Lab Bcn at IaaC) we unrolled each rib, we duplicated their borders and we fitted them in rectangulars of 450mm x 900mm that represent the plywood material of 3mm that we were going to use for the laser cutter.

After cutting each piece we assembled them with the help of the numbers that we engraved on them and we constructed the model of the bench.

The final model