This instructable can be applied to 3D printing any crown really, but depending on the design of the crown, there might be some difficulties creating the 3D model.
Step 1: Modelling the Crown - Part 1
I collect a bunch of reference photos.
I collected a few photos of the crown and realized that the basic antler design is repeated in quarters. This makes it easier to model as I only need to model a quarter of the entire crown and print it out 4 times.
BUT, if the crown's design is unique all-around, then create the vector graphic for the entire crown.
So the way we will get the curvature of the crown is to create an unwrapped, flat version of the crown and we'll do the wrapping in SolidWorks. (Imagine those paper crowns from Burger King)
First measure the circumference of your head where you'd like the crown to sit. This is how long the flatten crown needs to be.
If you are working with a reference photo that you're going to trace, resize the photo so that if unwrapped, it's the length you measured.
In my case, I'm tracing a quarter of the crown, so the size of my trace needs to be a quarter of the length I measured.
I only needed an approximation of the design of Joffrey's crown, so the minor curvature of the reference image isn't a concern to me. I also adjusted the vector artwork a bit to "flatten" the design.
Step 2: Modelling the Crown - Part 2
In SolidWorks, import the drawing in the correct planes. A simple crown may only need one drawing for the front plane, but with Joffrey's crown, there's a curve that's accomplished through an extrude cut along the profile (right-left plane)
SolidWorks allows you to take a prismatic solid and flex it. You can specify the end-planes of the flex and the origin of the flex as well as how many degrees to flex. There are two curves to this crown: the 45 degree curvature of the quarter-crown and the slight curve from bottom to top for the antlers. The images shows how the different stages of the flexes.
Step 3: Printing the Model
Step 4: Construction of the Crown and Painting
The crown from the show had a lot of textured marks on the crown, I opted not to add those textures. For my purposes, it wasn't that important.
After sanding, I glued the pieces together with superglue.
I painted the crown with a can of Krylon gold spray paint.
Because of timing, I wasn't able to find the amber jewels for the crown.
Step 5: Conclusion and Retrospection
The crown was also a bit larger than I expected. Since human heads are not perfectly circular, whereas the crown is, the crown can afford to be slightly smaller then the measured circumference of the head.
Attached is the STL file for the crown quarter. It was sized for a 57.5cm head circumference. If you plan on printing it out, adjust the scale accordingly.