This Halloween I wanted more than a carved out pumpkin. I wanted something scarier. A skull with red glowing eyes. So off to google I went to find, download and build one. There must be plenty of templates out there. Everyone loves skulls. That's what I thought, turns out I couldn't find one that had the amount of detail I wanted and was freely available.
I did find a lot of cute paperboys though. :) Sticking two red lights onto them wouldn't have been what I was looking for.
So I went ahead and built one just the way I wanted it:
Step 1: Reference
To be honest, I don't have a skull laying around here, so to get some reference I got a 3D-model of one on thingiverse. Again, I was surprised how many skulls there are, but also how far down I had to go to find one that suited my needs.
The model seems anatomically correct. With all the holes and cavities and separated jaw. I didn't care for correctness, the jawbone doesn't have to move. I also wanted something that was fairly easy to build. Alle the holes, bridges and cavities would have made it extremely hard to assemble.
Step 2: Building It in Blender
At first I tried to used the method I build the deer and moose with. Starting with the original model I reduced and reduced the number of points. But the model was too complex. Below 500 points things were falling apart.
So I switched to blender to build it by hand. Showing how to use blender is beyond this tutorial. There are plenty of resources on and off the web that help you to get going. I started with a course at the Volkshochschule Hamburg and goggled my way from there.
Even though I tried to keep the number of points down, I ended up with well over 300 points in my initial try. Eager to see how it would look, I unfolded it using pepakura and built my first prototype.
It turned out pretty good. It had it's quirks though. The cavities were too deep, I messed up the jawbone on side and I felt it still had too mach detail.
Step 3: Reducing Detail
Five Iterations later I had reduced the number of points by more than half while retaining most of the original shape. At least so I think ;)
Step 4: Building It by Hand the Traditional Way
So now it's time to build it.
I made templates for A3 paper that you can print out. You'll need 3 pages of card stock. I used 300 gr. but less will do. Normal 80gr. copy paper is probably a little too light. If you put the effort of cutting and glueing into it, you should take the time to get the right paper.
A quick reminder on how to build with these kind of templates:
- cut out the parts
- score and fold the dotted lines
- match sides by their numbers e.g. (25 to 25)
- glue together
There is no special order in which these have to be glued. I have started with the eyes and built the face first. Later on you'll close the skull and it will be harder to reach the flaps and glue them.
Step 5: Building It, Alternative
I find the matching of numbers fairly hard. I takes one edge to match a part. So I made a second template:
- Each part is named
- All edges that have matches on the same part are marked with triangles
- One edge that needs to be connected to another part is marked with a circle and a line to the matching edge on the other part. Where the matching part is on an other page the name of the part is next to the circle
- Most parts of one side of the skull are on one page
Let me know if you like this better than the number matching.
People were having issues with the SVGs. So I saved them as PDFs. They are ready to download above.
Step 6: Bonus: Use a Cricut Explore to Cut Out and Score the Parts
I was fortunate enough to win a Cricut Explore with the paper craft contest here on Instructables.
If you don't have a Cricut Explore or any other personal paper cutter skip the next few steps to add the LEDs
So here's how you load the SVGs into Design Space and set up all the layers.
Start with a new workspace and load one of the SVGs using the VECTOR UPLOAD.
Once you've loaded the SVG into your personal parts repository don't forget to mark it
You should now see a tiny black box and a few parts sticking out at the bottom.
Step 7: Bonus: Size the Parts
Design Space does not load the SVGs at their original size. Until that is fixed I include a 12x12 inch box with all my SVGs. Since you can't cut anything wider than 11.5 inches, that box will always be the widest element. Scaling the SVG up to 12 inch and moving it to the upper left corner by setting the x and y position to zero will get everything to it's correct size.
Now ungroup everything and delete the last layer to get rid of the 12x12 box. We don't need it anymore.
This project is meant to be built on A3 card stock. You will need to have a 24x12 inch cutting mat.
You can resize everything a little to fit smaller paper sizes. I made the glueing tabs fairly large so that they should still be big enough after scaling everything down.
Step 8: Bonus: Cut, Score and Draw
Now you have a bunch of layers. Play around with them, turn their visibility on and off to see what they contain. You may want to decide not to use one of them.
Time to set them up: We don't want all of them to be cut. Just one of them. The outline it the bottom most layer. So leave that the way it is.
The next one up are the score lines. Set that to scoring it you have the scoring stylus. If you don't you can set it to drawing. That way you'll know where to fold the paper later on.
The third one from the bottom are the valley folds. I draw them in, so i know which way to bend the folds later on. Valley folds are marked, mountain folds are not. Most of the folds are mountains.
Then comes a layer with the part names. It's easier to assemble if you know which part is what. It makes finding things a lot easier.
Then a layer for all edges that connect to another edge on the same part. Before I glue all the parts together I glue all the edges that need to join on the parts themselves.
Finally hints on how to connect the parts. There are either lines to the connecting part on the same page, or the connecting parts are written next to the little circle on the edge.
Before you start to cut them make sure you attach all layers.
Step 9: Assembly - the Eyes
Start with the eyes. If you want to add the LEDs, now is the time to do so. make to little holes for the pins sticking out in the back. Orientation doesn't matter.
Glue the LED in place and glue together all the self connecting edges.
Step 10: Making It Glow
Step 11: Symmetry
Continue to build both sides of the face, join them and attach the lower jaw.
Step 12: Work Your Way to the Back
Continue to work your way back now. Finding the right part should be easy now that there a just a few left. It is getting tighter. You're closing the skull bit by bit.
I choose not to close it all the way with the bottom plate. It's up to you if you want to be able to reach in or have it closed all around.
Step 13: Done
Of course you don't have to light it up with LEDs. You can build one and use it in your next Hamlet play... To be or not to be... ;) Or you can use gold spray and feel like an Atztek ruler...
Step 14: Bonus 2. the Joule-Thief
Using Lithium cells for the LEDs is by far the easiest way to the the thing to light up.
However there is an other way that you might want to consider. The Joule-Thief. It's a little board that takes old used and empty batteries and suck that last bit of energy out of them. Most of the batteries you throw out aren't empty, they just can't deliver the voltage they should. The Joule-Thief uses that little energy that's left which is plenty to drive the two LEDs we have.
I've built one in my local hacker space the Attraktor and made an instructable:
Mine has been running at full brightness for days now with a battery from the trash. :)
Step 15: Thank You
You've made it all the way here? Wow, congratulations. This must be the longest instruct able I've written so far.
I want thank everyone that has been part of this project.
You can thank me by sharing the link to this instructable and voting for me.