For this 3D printing assignment, I decided to create a hollow spinning top. This design leaves the majority of the top’s weight near the outside radius, maximizing its moment of inertia and angular momentum. To begin this project, I used the 2D drawing tools in IronCAD to draw half of the top’s cross-section.

Once the half cross-section was done, I used the rotational extrusion function in IronCAD to rotate the edge 360 degrees and create a solid part.

The whole point of this project was to make a hollow top, because this could only be reasonably manufactured via 3D printing, so now I had to find a way to turn this solid object into a hollow surface. Luckily, IronCAD’s shell tool made this fairly simple. I just set the width that I wanted to be left on the outside of the object and clicked finish. I also added a hollow cylinder through the spinning handle of the top in order to leave an opening for the filler material to be removed after printing.

(Hole through body of top is only there to show that the piece is hollow throughout)

At this point, I believed that I was pretty much ready to print; however, after Carlos took a look at the design and at how much fill material would be needed to produce the top, he advised me to add a few more openings for the solution to enter and exit the top. I thought about it for a minute and decided that I wanted to do something a little more fun than just add some holes to the top. I came up with the idea to use the letters in my name as the holes for the solution to be washed out through. I was not sure how exactly to make letters in IronCAD, but I did remember that Tinkercad had some nice standard letters already made, so I exported the piece as a .stl file, then imported this file into Tinkercad. Once in Tinkercad I was able to put my name on the top and then add a few stars for a bit of extra design. This worked out really well, and really helped with the potential problem of washing out all of the 3D printed filler.

Now the top was really ready to be printed. We used the Fortus printer, which worked quite well because of the nice rigid plastic and ease of removing the support material with the chemical bath. The top took about 3hrs. to print and came out quite nicely!