“The manufacturing process aims to succesively reduce material from the stock model until it reaches the final shape of the designed part. To accomplish this, the typical machining strategy is to first use large tools to perform bulk removal from the stock, then use progressively smaller tools to remove smaller amounts of material. When the part has a uniform amount of stock remaining, a small tool is used to remove this uniform stock layer.”

CONCEPT:

For the bench we decided on a sculptural look. Considering it was to be fabricated out of plywood we wanted to counter the rigidity of the waffle structure with fluidity of the surfaces. It is designed as a two seats accessed from opposite sides. The interplay of surfaces and heights creates the back rest and seating for each side at the same time maintaining the homogenity of the bench.

PROCEDURE FOR CREATING WAFFLE STRUCTURE OF BENCH:

Step 1: We started with the bench template. Applying cage edit the bench was modified along the control points to the desired shape keeping the two side surfaces intact to allow for connection with other benches. The height and widths were modified within the control box.

Step 2: Once the bench shape was finalised and we ran a check for the following the external parameters of the bounding box, we proceeded with creating the waffle structure to obtain surfaces for the laser cutting. Firstly the various layers were created in the rhino file.

Step 3: First we off-setted the outer surface to the required thickness to have two separate surfaces. Instead of countouring we introduced planes in the X-Y direction. For this a plane was introduced along one end of the bench for planes along the X-direction and arrayed along the length of the bench. Similar thing was done along the Y direction. We now had intersecting planes in both directions.

Step 4: The outer part of the planes were trimmed along the outer surface of the bench to get the outer ring. The inner part of the plane was trimmed along the inner surface of the bench. The trimmed panel was thus achieved in the X direction and similarly obtained for the sections in the Y direction.

Step 5: Changing the layer the planes were intersected to get the lines of intersection between the surfaces in the X & Y direction.

Step 6: Two solid pipes were drawn for X and Y direction, put in separate layers and copied at every intersection – one for the intersection along the X direction and the other for the intersection along the Y direction. The diameter of the pipe was kept as 2.8mm.

Step 7: Using ‘Intersect’ the pipes were intersected with the planes. This was done separately for the planes in the X and Y direction keeping only the required layers switched on.

Step 8: The surfaces were then unrolled using ‘Unrollsurface’ separately in the X and Y direction.

Step 9: the ribes were gruped an arranged on the plywood sheet size of 1.2×2.5m using ‘Rhino nest’. The curves were simplified using Curves Edit tools- ‘ simplify lines and cuerves’ and saved as a .dxf file for printing.

The aim of this assignment was to create a foam model of our barrio using the CNC Milling machine. We first prepared a 2d rhino file of our barrio which had to be printed in the laser cutter at the scale of 1:5000 and on which we discussed and examined various issues concerning the 3d printing process and the way of union the different barrios (boarders, designing methods etc.). The file comprised the streets, the blocks and the buildings, all organized in one layer in order to be engraved. The boarders of the barrio were organized in a second layer determining the cutting lines.

We created the 3d rhino file using the required information from the web and we organized the buildings in layers, according to the number of floors of each building, giving finally the corresponding height. We added the 3 cm base of the model and the 2 mm height sidewalks and we changed the scale into 1:2000. We converted the polysurfaces into meshes and union them all together.

A barrio (Camp de l’ Arpa) that has not been previously allocated to any of the groups was added to ours a posteriori. Finally, the model was printed successfully in one piece. Because of the different height of the materials, we had to cut our piece through horizontally manually, in order to fit with the neighbor areas.

The digital design process

The fabrication process in CNC Milling machine & the final model

The aim of this assignment was to create a foam model of our barrio using the CNC Milling machine. We first prepared a 2d rhino file of our barrio which had to be printed in the laser cutter at the scale of 1:5000 and on which we discussed and examined various issues concerning the 3d printing process and the way of union the different barrios (boarders, designing methods etc.). The file comprised the streets, the blocks and the buildings, all organized in one layer in order to be engraved. The boarders of the barrio were organized in a second layer determining the cutting lines.

We created the 3d rhino file using the required information from the web and we organized the buildings in layers, according to the number of floors of each building, giving finally the corresponding height. We added the 3 cm base of the model and the 2 mm height sidewalks and we changed the scale into 1:2000. We converted the polysurfaces into meshes and union them all together.

A barrio (Camp de l’ Arpa) that has not been previously allocated to any of the groups was added to ours a posteriori. Finally, the model was printed successfully in one piece. Because of the different height of the materials, we had to cut our piece through horizontally manually, in order to fit with the neighbor areas.

The digital design process

The fabrication process in CNC Milling machine & the final model

At first the mashine type has to be set to 3 axis milling; for the post processor we choose “precix” and finally the stock can be set or by typing th estock measures manually or by picking a modelled stock volume as a reference;

The milling process and its setup happens in two runs, for each setup a polyline needs to be selected  ( yellow line in first image) to determine the outline of the 3d model.

1.) Horizontal roughing – horizontal roughing is for fast and efficient removal of material as a preparation for th emore refined second milling step.

A thicker ball pointed milling tool with 26 mm of diameter was used in this case.

The step over control panel and the stepdown control were set in accordance with the tools with and length  and the desired precision of the milling.

2.) Parallel finishing – this is the final milling porcess in which the resolution of th emodel is being refined after the horizontal roughing has been done.

The tool we used was a 3mm thin ball point.

The stepover parameter was set in accordance with thefinishing tools diameter; in order not to damage the stock we set a clearance value of the stocks hight + 6 mm.

Finally we could export the .gc file including the g code ( coordinates and sequence ) for the movement of the milling mashine.

X17.152
X17.103 Y-29.437
X17.561
X17.665 Y-29.407
X17.055
X17.05 Y-29.404
X17.043 Y-29.378
X17.769
X17.873 Y-29.348
X17.034
X17.026 Y-29.319
X17.88
………………………

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As an overall analysis of Design Studio I “ZEBAR” Project, the assignment claimed for a 3D model of Barcelona.  Following the admistrative subdivisions of the city, a digital 2D CAD format map was created by tracing closed polylines for streets, blocks and buildings.  It was decided that the entire city would be considered flat and only the topography of the most important mountains (Montjuic, Collserola, El Carmel) would be shown since the scale is 1:2000 and not all details would be seen.

Rhino file

Therefore, the printing was separated into 2 parts, the flat and the topography, in our case Ronda del Dalt street was the subdivision element. Having decided that, the extrusion of all the buildings was done considering that each floor is 3.5m high. The blocks were extruded to a 0.3cm height and the base 3cm due to the thickness of the material.  After receiving the topography treated with RhinoTerrain plugin, we had to place the buildings on it. We placed them above the terrain and then individually chose Curve>Curve from Objects>Duplicate Edges. Selecting each edge of the base of the building, we joined the lines and hit Project. Click on the terrain to project the curve on the topography. Then we moved vertically the building to the lowest point in the terrain so the building would be placed inside it.Then “Boolean union” all the buildings, blocks, and streets in order to create one single object. Eventually Create a mesh of the object by applying the command “mesh” and place the model on a sheet size is 1990 x 990 mm. Since our barrio is a big area, we have to split the area into 2 parts in order to fit into the sheet.

Buildings on Collserola Mountain

In order to materialize the 3d model we chose foam and milled with the CNC milling machine. The file was first prepared to be read by the machine through a simulation of the milling using Rhino Cam. To start milling, we used 2 tools with different diameters. First 3cm tool to take out the excessive material, and then 26mm to give detail into the map.

Foam Model milled with different tools

Saint Gervasi milled

During the milling process, the northern part of our area was only engraved and not milled. After sometime working on the file to find the mistake we realized that some meshes were open and invalid through the command Analyze>Edge Tools> Show Edges. We used the command CloseCrv to close all the polylines and redid the extrusions and meshes. Finally with Command “What” we knew there was no more invalid meshes and the file was ready to be reprinted.