This is my own personal skull design, it took a lot of time to shape it into what it is, and there is always room for improvement. I attached the CAD files to the the CADing step, and the final STL file to the final step. This way if instead you wanted to add your own creative touch, you can modify it to your liking.
I can't express in words how much I love the idea of 3D printing and that is why that would be my ideal choice of turning the 3D model into a physical model however if you have a really nice CNC, it would be hard but could be possible, to make the skull out of a material of choice like foam, metal, or other composites with good material properties for being machined.
Step 1: Develop Ideas
In order to do this effectively I can't stress enough how important it is that when you start a project you expose yourself to as many worldly items as possible, don't limit yourself to researching what has already been done. Walk around the aisles of a large superstore, look at toys, household items, electronics, or even food. On your daily drive (or ride) to work or school observe everything as something that could possibly work for what you need. It is amazing how sometimes an item used in a totally different area in your life could be applied to the field of what you want to create.
For this project I started with Google's image search because my design didn't have to be functional, it just needs to be visually appealing. Where best to look for something that you find visually appealing, than browsing through hundreds of pictures and art? Several skulls caught my eye, in general finding dragon skulls themselves was a lot harder to find than I had originally thought. After browsing through both live and dead dragons I started sketching to get some ideas out. The two main features I had to decide on were the general skull shape itself and what type of horns and horn placement did I want to have. The main picture is what I came up with.
If you have a hard time with drawing or need a place to start for general dragon form, look here to help you get started.
The really dark spots on the skull will be material that is removed to take into account things like eye sockets and breathing holes (some are just for decoration). The dark-fading-to-light spots are there to indicate that the skull is indented and the indent gets shallower as it reaches the main surface of the skull. The horns are (poorly) shaded to look round. Then, I decided that for simplicity sake, I would start with the design that had the least amount of features so that I could get practice seeing how to make this form right in Pro-E the CAD software I used.
After I chose my design I needed to think about how big I wanted the skull to be, I just chose easy dimensions but I wanted a 2:1 ratio for length of the skull to width and height. A really rough sketch of the top view of the skull is shown with the dimensions. I think that my dimensions turned out way different than I had planned since the horns have to be almost as long as the skull is.
The beauty of the shape of the skull is that because it is hollow in nature it has an enormous range of uses. In general my nerdy nature made me start to think along the lines of armor for this project, however it is your own creativity that makes "something" into anything.
• Wearing as a mask, helmet, shoulder guard, backpack, etc.
• Household decoration such as a wall trophy, mantle piece, room decor, or upside down as a basket or dish.
• Miniature sized for a figurine, doll dress up, or game oriented.
***This design does have a jaw bone (which I have hidden in some of the pictures) included in the CAD files in case you wanted to use it as well.
Step 2: Start CADing
It took me a bit of time to figure out how to do such a complex shape. When I started exploring around Pro-E's features I ran across an option called "Warp." Under the Warp feature there are several different types of warping, I chose the one called "sculpt" because it didn't require all the dimensions to be known and I could customize it however I wanted. How it works is you select any surface on a previously extruded body and then you can make an array of points across that surface with whatever density you want, as shown in one of the pictures I created a rectangle as the extrude and placed dozens of points across it. After that you can click on one, or hold CTL and select several points, and physically drag them in a direction perpendicular to your surface. This allows you to place some points higher or lower than others.
First, I chose the top surface of my rectangle and spent time dragging dots until I liked the shape of the skull from the top. It took a lot of trial and error until I got it how I wanted it. I then saved it and started a new sculpt on one of the sides.
There are three depth choices, the first choice applies the movement of the selected dots to only the selected side of your extruded part like I did for the first sculpt. The second choice applies the changes in dot movement to both sides of the extruded part so if you curved one side out the other side would curve in the same amount. The last option, which is the one I used for the sides of the skull, moves the other side symmetrically so that if you moved a dot out on the other side a dot would also move outward.
Next up was the horns. I saved the skull and opened up a new part. I wanted to start on the backwards sweeping horns coming off the side first. The horns were the most difficult part because I ended up having to get a friend's help on how to get the feature to work. I started out by making a drawing of a straight line. Then I used the swept blend feature. You select the path you want the feature to go along, which was the straight line I drew previously. Then you can create whatever kind of shape you want at either end of the lines, I chose a really large hexagon on one end and a really really small hexagon at the other end which is what gives it the ridges. The blend then creates a solid model connecting the two shapes along the drawn path, you can also chose to just create a thin shell if you don't want it solid (to save on weight).
Using the same warp feature as I used before, except placing it on the "twist" option, it will twist one end of the model around a point as many degrees as you choose. If you look at the pictures it should make better sense. Then you can use the sculpt feature to place curve into the horn in the side-to-side and up-and-down directions. Now that we have a single horn done, to make two we can mirror the horn about a line or plane. This same technique is used to make the top set of horns.
The final horns, both side and top, are shown. The smaller horns on the nose, and the teeth can all be made with the same technique. In the image I put on the front of the Instructable you can see I was playing around and used the same horns on the nose and placed them along the eyebrow ridges of the skull.
I made this expecting to be able to size down the model but sadly the warp feature does not scale down like the rest of the features do. So I suggest maybe using a different method for making the skull, however I did find that when you import the STL file into other programs resizing is still a possibility.
Step 3: Assembly
The first picture is an example because sometimes after you start putting things in assembly you notice things like blue sketch lines appear that you don't want there (or in this case I have the bottom half of the jaw as well). In order to fix this you need to go back and open the original part.
In the second picture you can see I clicked on the blue lines and they turned red, because I held the CTL key to select multiple sketches you can see on my model tree that two components are now highlighted in blue. If you right click, on either of the highlighted components, the drop box appears as shown and you want to select "hide." This is a useful feature because it will only hide the component from sight, not permanently delete the component, and you can always go back and unhide it if you decide later you want to use it. Save the file and then you can close this window or just move back over to your assembly. I just found out that it isn't necessary to hide the sketch lines when you convert it to STL, they will automatically disappear. Now the blue lines should have disappeared after you saved but if they didn’t you can go to the edit tab and select “regenerate” to fix it. You can also hide the bottom jaw by right clicking and hiding it as well.
So now you have your final assembled skull, congratulations! If you wanted to decide to hide the teeth because when 3D, depending on the use, they might stab things. You can do this now before creating the STL file or another choice besides hiding them is to delete them entirely from the assembly if you never plan on using them.
Step 4: Print It!
Then you can either print it yourself on your own 3D printer, if you don't have the resources to do this, there are several sites like Shapeways allow you to upload your model so they can print it for you. I want to give a reallyspecial thanks to the Instructables team, and audreyobscura who printed me a copy to share with you! The dragon skull seen was printed on an Objet Connex 500 3D printer. Also, I included the STL file as the second image, let me know if this works for you!
I hope this Instructable inspired you to start creating, I can't wait to see what you guy's come up with so if you end up creating your own 3D model or print, send me pictures!! You can also find the model uploaded to 123D's site, I don't know why but the second horn isn't showing on the images, but it is still in the list of items.