In my last post you learned how I created the basic shape of the hull. Today I will further detail the 3D model and show you the results of my 3D prints. Once you have the basic hull shape it is now very easy with modern CAD systems to project the lines each section produces. Think about how they have done it 100 years ago. They created a scale model out of a solid piece of wood and then cut it into sections with a band saw. The CAD system can create 126 sections spaced by one foot in a couple of minutes. In the picture below I spaced the sections 9 feet.
You can now use the section curves to create ribs in the CAD model. This process again is fairly quick. In the following picture I created 4″ * 4″ ribs spaced by 1 foot which are the dimensions I took out of a picture showing a small hull section with ribs I already shared in the previous post. The result is the frame of the Zodiac what is must looked like when it was build 90 years ago. Today most of the ribs have been doubled up to add additional strength.
At this point I have enough model data to actually start printing the hull on my 3D printer. Most 3D printers need an STL file to be able to print your CAD model. This is a pure surface description based on triangles connected to each other. You just have tens of thousands if not millions of these small triangles to represent the surface you want to print. Below you see how the CAD software created the mesh. I did increased the number of polygons to get a better and smoother surface in the printer later.
After I exported the hull I then loaded it into the 3D printer software that scales the model to fit it within the 12*12*12 cm box which represents the maximum part size the printer can produce. Now I’m ready to print.
After about 2 hours my first small hull emerged from the printer. The result was actually pretty amazing and I now had a model I could touch and feel. I also noticed right away that the back of the hull wasn’t quite right. I also lost the rudder which wasn’t printed properly.
But over the next few days I further improved the CAD model and even sliced it into three section so I could print a larger hull. After each section was printed I just super glued them together. The following sequence of pictures show you various results. Up next is scanning the hull of the 127 foot schooner Zodiac. So stay tuned.