Re-building the Form

Taking the new form, in which Calvin added a third opening, we began rebuilding the lattice structure. The above image shows the sequence of steps I took.

First I had to re-triangulate the edge of the new opening.

Then I traced each triangle with a polyline. In doing this could then go back and create surfaces from each planar curve. I then offset each triangle on their appropriate surface. Each triangel can now be extruded using the "fin" command.


Team K

Since we are now continuing on this design as a team our work is now spread out. We have decided to move away from pipes. Our six main structural ribs are now rectilinear in cross section. This allows us to to easily manufacturer them by laminating plywood pieces. Take a look at Marilyn's blog for some images of this change.

We are also continuing to improve the connection of the triangulated bracing. Again, we want to move away from pipes. We are proposing a new design where the bracing is inset between each rib. Images of this can be seen on Jorge's blog. We are still working on this connection as there are issues that arise from the rectangular ribs being arrayed at an angle and not perpendicular to the ground plane. The advantage of this new connection, however, is that only angles between the braces, along the surface of the form, need to be predetermined but the angle in the second dimension remains flexible.

EX_03 Structure Connections

Upon first creating the bracing between the ribs they were simply laid down and there was no method of connection. I though the most straight forward way of connecting the braces to the ribs would be to simply bolt them together. To do this each end of the diagonal bracing would have to be flattened. I tried several approaches to achieve this all of which were unsuccessful. I had the best luck with the cage edit tool. Although I'm sure there is a much better way to do this-one that would give me better results too.
I then overlapped all for braces at the point of connection, created a hole and threaded a bolt through. Nothing exciting but it will definitely work.

EX_03 Triangulated Structure

Beginning with one surface, I applied a triangular pattern on a grid of 5x30 points. Following the grid I created 5 ribs to act as the primary structure. I then began adding triangulated bracing between the ribs with secondary piping.
The above shows the same steps with out the forms surface.

To create the secondary structure I offset the surface and grid towards the interior of the form by a distance of the radius of the ribs. I initially wanted to separate the secondary structure by having on all bracing going one direction on the interior of the ribs and all the bracing going the opposite direction to be on the exterior of the ribs. This in a sense would create 3 layers of structure. However, has you can tell from the image below when I offset the the surface and grid to the exterior of the ribs, the intersections of the triangle patterns did not line up. Thus, I placed all of the secondary structure into the interior of the ribs.

Another problem I came across that I could not solve was that some of my control points for the secondary structure did not offset enough and some of the bracing intersects with the ribs. This is displayed in the image below. The problem only occurs at the smaller end of the form where the ribs lift off the ground.

And here are a few different view of the final product, with all bracing on the interior of the ribs.