Large Wooden (Easter) Eggs

Recently I challenged myself to design something round/ organic on a laser cutter. Projects made on a laser cutter often tend to be square or inorganic, and I wanted to see if I could make something smooth. Since I just finished a design that connected multiple pentagonal panels together into a dodecahedron, I settled on making a low poly shape. With easter coming up, and it being a nice symmetrical shape along one axis, I decided on making an egg!

Even though these eggs require some patience to put together, they look great! Just put them on a shelf, or together in a basket. Furthermore, by painting or engraving specific panels of these eggs you can make some fun patterns. I designed these eggs to have 12 fold rotational symmetry, across 8 layers (plus a top and bottom), thus making them great for adding symmetrical patterns.

Good luck building these fun eggs, and I hope to inspire you all to make your own fun projects!

Well, I don't think you are going to find many supply lists that are more boring than this one, since all you need is a sheet of 3mm plywood. Acrylic might work as well, but it will provide additional challenges since it is more brittle. But since there are some tools that might make your life easier whilst putting this thing together, I guess I add a list anyway:

Materials:

• A sheet of 3mm plywood, 30 by 60 centimeter should be large enough. multiple smaller sheets works as well. If possible you could use different types of wood, or stained woods to get different colors on the eggs.

Tools:

• Duct tape. This could be useful for getting the triangles out of the lasercutter without them falling through the bed.
• A hammer with a rubber head. This saves your fingers some stress when press fitting all triangles on the model
• A laser cutter (duh)

In order for these eggs to get their nice smooth shape, they need to contain quite some parts:

• 4 different rings, one of each, for the core structure
• 2 sets of 12 ribs that connects to the rings
• 18 sets of 12 triangles that connect to the core structure

Because of the large amount of parts, it would be very convenient if no glue is needed to put this thing together. Luckily there is a way to do this! If we account for the amount of material that the lasercutter cuts away (kerf) we can cut parts that tightly connect together, just using friction.

In order to do this, it is important that you know how much you need to offset all shapes in order to have them fit together. Here is another instructable that goes into some more detail on how to measure your kerf. Once you have your kerf, I advise you to cut out a single rib and some triangles to see how well they fit together. I adjust my kerf using this add-in for fusion 360, but there will definitely be other ways to offset dxffiles. If your cut parts don't fit snuggly, adjust the kerf again until they fit snuggly.

Now that you have your laser cutter dialed in you can cut out all 268 needed parts!! Be aware that if you use the file with un-marked triangles, you will need to pay attention to their location to remember where they go.

I provided the files with a few different kerf offsets, these files are not labeled though. The triangles are instead ordered from top to bottom. If one of these files does not have the correct kerf, you will have to do this yourself by editing the dxf, of you can use the fusion 360 file and use the add-in mentioned above to export with kerf. If you cut the non labeled files, it could help to put duct tape over the cut out parts. this makes it easy to take everything out all together (see last image of this step). some of the images of this step provide references about which parts go where.

Since for the laser cutter I used, I adjust for a kerf of .25 mm, I provided a fully labeled nested file for that as well.

Note:

The fusion 360 file might be a tiny bit of a mess. I am not extremely experienced in fusion 360. If you export the dxf directly from fusion, make sure to select only the parts of the outer shell and skeleton components. Also note that the order in which you select the bodies for exporting, is also the order in which they appear in the dxf file.

Once everything is cut out, you can start building. Take the four different rings, and the two sets of 12 ribs. If you cut the labeled files, it should be quite straightforward how they go together. If you have the non-labeled version, you can use the labeled file for reference. Every only fits together one way, so it should be doable. Make sure that the entire core is pressed together tightly. You can do this by looking at the top or bottom. These should look like they ar nice round circles. Do not hammer these sections down, you could potentially damage the pins.

Welcome to the most fun step of this build, adding the tiles!!

Whilst time consuming, making your own patterns is lots of fun. You can just lay out your triangles in front of you, sorted by shape/number, and select the ones you like for your pattern. Just press them on the correct pins. You dont have to press them all the way yet. We take care of that in the next step.

Make sure to take your time to check if you put the triangles on the right place. Whilst each triangle of a set of 12 is symmetrical to each other, the triangles from different sets are definitely not, no matter how similar they look. If you manage to mix them together by accident, it might just be better to cut them out again.

Come up with some fun patterns beforehand, or create them as you go, just have fun! :)

In order to make sure everything is put tightly together, now grab you rubber mallet and gently tap all the pieces. This step ensures you will get a more symmetric egg that has all pieces aligned correctly.

You should now have a great looking egg, congratulations! Put it on display as an art piece, somewhere in a basket as easter decoration, or give it to someone else!

If you feel like an extra challenge, I still have some things that I did not have time for to implement yet, these are:

• Creating a map that allows you to wrap images around these eggs, by engraving parts of the image on each triangle individually, before putting it together. I was thinking on wrapping an engraving of Starry Night on it for example, but I have no idea how it would work out
• Creating a box out of one of these eggs. As you can see from the third image of this step I did get to making a design that allows you to take the two halves apart. It was however quite fragile, and I did not get to improving it yet. Furthermore, this would just be a container where you just pull the lid off. I'd love to design it in a way in which it contains a twist and pull mechanism that closes and opens the lid. There is however not to much space to work with, but it sounds fun.

I hope you got something useful out of this instructable. If you have any questions, feel free to ask!

See you on my next project! (hopefully)