# Build a Frabjous

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A frabjous is a cool looking dodecahedron structure made out of 30 "S" shaped pieces. Designed by George Hart (http://www.georgehart.com/sculpture/frabjous.html), my cardboard frabjous was inspired by evilmadscientist.com. Use his Flickr to help get a sense of where the pieces go.

Materials:
Lots of cardboard
Box cutter/Hobby knife
Tape
Hot glue
Post-it notes

## Step 1: Cut Out the Pieces

Print out the frabjous template and use it to cut out all 30 shapes.

This step takes a long time. I did it over the course of a week because I went through several blades and it tires out your shoulder. The cardboard gets bent and damaged sometimes but that is not a big deal.

When spray painting mine, I put a primer down first to help stiffen the cardboard up a bit. I then used indoor chrome spray paint because it sticks best.

## Step 2: Start Assembly

I started off by gluing three of those pyramids together. Make sure all the pieces are oriented in the same direction! Mine are turned like a reverse "S" - orienting them the other way will work perfectly well too. Don't make anymore than 3 pyramids because it is much easier to work with the single pieces afterwards (it's probably impossible to build without using the single pieces).

A frabjous has a total of 20 points on the surface connecting 3 "S" shapes together. In order to figure out where each piece goes, it is best to number the points (which I have done in one of the pictures) and divide them into four layers. The Upper Layer contains points 1-5, the Upper Middle Layer points 6-10, the Lower Middle Layer points 11-15, and the Lower Layer points 16-20.

When assembling, it is best to always work with the Upper Layer and renumber the points to put the pieces in place. As you can see in the diagram, point 1 connects across to point 13. What's not show is where the other pieces that are connected to point 1 go. Those other two pieces are connected to the Lower Layer at points 17 and 19. When looking at this two dimensionally, it looks a little like a "W" - all the pyramids within the structure follow this pattern.

Point 2 connects to 14, 18, and 20
Point 6 connects to 8, 9, and 18
Point 11 connects to 4, 13, and 14
Point 16 connects to 3, 5, and 9

In my second picture, the two pyramids are held at points 1 and 3, and they are connected at point 19. In the 3rd picture with three pyramids, the intersections are points 1, 3, and 4 connected at points 19 and 17.

Only the intersections at points 1, 3, and 4 are glued. All other connections from on out should be with tape in order to correct mistakes.

## Step 3: Continue the Pattern

Once the three pyramids were put together, we started using the Post-It Notes to keep track of the points. We even used different colors to identify the four layers.

On each side of the dodecahedron we start with points 1,3, and 4 because it helped stabilize the frabjous and made the construct pattern the same everywhere. When you add in points 2 and 5, the top blossom should be finished (Pic 2).

Picture 3 shows the underneath of the first blossom, which has now become the Upper Layer. Re-number and insert the next five piece to create the second blossom. Make sure the spiral pattern is correct on all the blossoms. Each piece should go over 2 pieces, and under the other 2 pieces.

Once that is finished, flip over to another unfinished blossom, re-number, and finish the blossom. The hardest part here is figuring out if a piece should go under or over one already established. Keep the blossom spiral in mind and you should be able to figure it out. We had to undo and reconnect at least 10 shapes because they were out of place. Don't be afraid to be forceful with the cardboard, it can handle it. An accidental fold is barely noticeable when it is finished.

## Step 4: Glue It Together

Over the course of the build, the frabjous will go from looking beautiful to ugly and back again several times. When all taped together, it will sag a bit. Once you hot glue it, the frabjous will be more sound. However, it is still fragile to touch because there is no support in the middle, only at the 20 intersections. It's a pretty sweet decoration.

Edit: Added some pictures with a light in the center due to popular demand. Unfortunately my low quality camera does a poor job capturing the true look, but I hope it gives everyone a good idea of what it looks like.

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## 55 Discussions

Ouch! My head was about to explode reading the explanations! I'm one of these math-challenged types that broke out in hives just before taking college algebra... but I am totally enthralled with the resulting beautiful object d' art or however that is said in French?? :) I'm content to admire it and congratulate you on a beautiful, clever and challenging instructable. And to think, I was only searching for "how to use gold foil" when this turned up in the results? Very nice!!

This was impossible for a year... until... I found this site:
http://www.thingiverse.com/thing:5449

Scroll down and print out the template for the 'dodecahedronlabeled.pdf'. Make the dodecahedron. It shows you how to match up the ends of a frabjous. You will love the person who made this available :)

Papercraft is one of my hobbys, but with this one, I have to confess that I´ve got completely lost. Until the end of step 2 everything worked really fine. My model was exactly as the photo. But after that, I´ve got a monster over my table, that didn´t look like anything on the photos. I´ve completed the conections table to organize myself but I simply can´t manage to put each "S" on the correct position.
Point  1 connects to 13, 17, and 19
Point  2 connects to 14, 18, and 20
Point  3 connects to 15, 16, and 19
Point  4 connects to 11, 17, and 20
Point  5 connects to 12, 16, and 18
Point  6 connects to  8,  9, and 18
Point  7 connects to  9, 10, and 19
Point  8 connects to  6, 10, and 20
Point  9 connects to  6,  7, and 16
Point 10 connects to  7,  8, and 17
Point 11 connects to  4, 13, and 14
Point 12 connects to  5, 14, and 15
Point 13 connects to  1, 11, and 15
Point 14 connects to  2, 11, and 12
Point 15 connects to  3, 12, and 13
Point 16 connects to  3,  5, and  9
Point 17 connects to  1,  4, and 10
Point 18 connects to  2,  5, and  6
Point 19 connects to  1,  3, and  7
Point 20 connects to  2,  4, and  8
I know that all this numbers are correct, but  is there any way to know how to overlap each part?

2 replies

I haven't built it yet, but it appears to be arranged like the compound of five intersecting tetrahedra. If anyone else trying to build this has some capacity for intermediate-level origami, I'd recommend folding Tom Hull's five intersecting tetrahedra to get used to how the symmetries work. The folding of the thirty pieces themselves isn't very difficult, it's the assembly that gets interesting. It's less confusing than this Frabjous, because the pieces are straight instead of S-shaped, so it seems like it would be some good practice. Plus, you'll have an awesome origami sculpture to show for it! :-D

This certainly was a big problem we ran into when putting this together. Be patient, this part is more about brute force and constant corrections than a systematic order.

It sounds like you have all the pieces connected to the correct blossoms even if they are not in the correct spiral order, which is where we wound up too. I talked briefly in Step 3 about how to make the corrections but here are some more details.

Start with a blossom and identify a piece that does NOT have two pieces underneath it and overlapping it (within the blossom, don't worry about the internal structure). See if the other half of the piece in a different blossom is in the correct spiral position, with two pieces overlapping and two underneath. If both halves are out of position, then re-thread the whole piece into the correction position for the two spirals. If only one half is out of position than you can probably just manipulate a few pieces in the blossom to get it in the right spot.

Get each blossom in the correct spiral pattern one at a time and repeat the process for each blossom, and hopefully by the end everything will be oriented properly.

This problem was why I noted to be forceful with the pieces because we had to reorient a lot of them within the structure and nearly broke the thing a few times. Doing it in paper might make this process easier since it is more flexible.

Well, I hope you understood that and that I could help. Please let me know how it turns out.

I am lucky enough to have the use of a laser cutter. I've just cut all the pieces out of clear acrylic and now all I have to do is put it together. I put little holes to wire it together at the joints. Only problem is I'm loosing my mind because I can't put it together. So confusing. I'll take a day off from this and come back to it when I have 5 hours to put it together. Thank you for doing this. I know it will be awesome when I finish mine. If I finish...

T'was brillig and the slithy toves did gyre and gimble in the wabe. All Mimsy were the borogoves and the mome wraths outgrabe. Ahh... middle school.

I made one out of red vinyl, and I'm very pleased with how it came out. I'm about to post a slideshow with pictures of the process. Thanks for the fantastic instructable!

Look great! It's incredible you constructed this from 30 identical shapes!

I was just wondering... has anyone tried placing a light source inside? Is there room for it?

The first time I saw this instructable I thought "Hey, that'd look slick in sheet-metal". Then again, if you built up a plexiglass one and had a light source in the centre, thatd look incredibly cool.

In my second picture, the two pyramids are held at points 1 and 3, and they are connected at point 19. In the 3rd picture with three pyramids, the intersections are points 1, 3, and 4 connected at points 19 and 17 So the point 17 is the joint of 1 & 4? or 3&4?