Some years ago I was shown how to make a replica of George Hart's 72 pencils sculpture. It is a fun process, but quite involved and requires a fair degree of skill. I wanted to make another one as a gift, but wanted to do so much faster, so I decided to 3D print some scaffolds to make the process easier. It worked so well I designed additional ones for round pencils and for crayons. This would make for a fun family activity, and the result is an unusual crafty gift for anyone who likes drawing.

Supplies

You will need a pack of 72 pencils or 24 crayons. For the colored pencils, I had to buy 120 to get the 72 I needed. The tolerances on the 3D prints is pretty tight so I cannot guarantee the prints will work for other brands. But you should be able to simply scale up or down the print to accommodate different diameter pencils. You will also need some rubber bands, and if you want to make the sculpture permanent, some superglue (one of the little 4 g bottles is plenty). You'll also need access to a 3D printer (I printed these on an Ender 3). The .stl files are attached.

Step 1: 36 Pencils

Print 3 of the templates. I found threading a 4th set to fail, as the friction was too high to allow 18 pencils to thread at the same time, so I just did them one at a time. Fill two templates with 18 pencils each, and intersect them as shown.

Step 2: The Next 18 Pencils

Thread the third ring through the other two as shown. From above, it is 120 degrees from the first intersecting set. Getting this set through is tricky - if there is too much friction, remove a few pencils (and pop them back in afterwards). Don't force it - if you have to, you've almost certainly got the alignment wrong. Look at the pictures and try again. You're looking to find hexagonal-shaped holes to put the pencils through, and they should be aligned to the edges of the previous rings.

Step 3: The Last 18 Pencils

Put rubber bands around the 3 rings you've made so far. Rotate 120 degrees, and without the template this time, just push the 18 pencils through one at a time in the same ring configuration.

Step 4: Realign and Superglue

Once you have all of the pencils in place, you may need to align the pencils. Just place the sculpture on one ring of pencils on a flat surface, and gently push the pencils down so they are at the same height. Repeat 3 more times. Once it is perfect, you're either done (if you want a temporary sculpture) or add a drop of superglue at the exposed joints (if you want a permanent sculpture). The second photo is a close up of the one I made & superglued 10 years ago - it is still in my office. It's easy to see the hexagonal holes in this picture.

Step 5: Colored Pencils

The colored pencil sculpture here was definitely a bit harder than the hexagonal pencils one, so I suggest practicing with the other one first! The main issue is that the hexagonal shape of the regular pencils make the right holes easier to see, and the paint on the outside of the colored pencils seemed grabbier somehow. The pencils themselves are also shorter, which gives you less margin for error. But the final sculpture looks very colorful and gives you plenty of scope for creativity in terms of your color choices. I used reddish, yellowish, greenish and bluish for the four rings of mine.

Step 6: Crayons

I made some crayon templates too! Print four of these because you can push each ring of six through easily. Replace the templates with rubber bands once everything is in place.

I didn't try it, but I do wonder if you took the paper off and hit this with a heat gun if you could melt the crayons together? Might be messy, might be wacky. If anyone tries it I'd love to see the results.