No Tape Cardboard Stool - 18 In. 180+ Lbs - No Glue, No Tape, No Fasteners!

This is a project created for my university's Industrial Design admittance class. The task was to design a stool out of cardboard that can support at least 180 pounds without fasteners of any kind. For this project, my solution involves 3 pieces- two which form the load-bearing 'x' and a third that goes over the top to form a continuous seating surface and to provide additional rigidity. I worked very hard on this project and you can read more about my full design process making prototypes and using CAD (especially the sheet metal function) in this slideshow:

https://docs.google.com/presentation/d/1RZ7QgjAAkvgbK_nGlPDDcUVMK7FH-kfPExFxrYSDtRQ/edit?usp=sharing

During this class we also weren't allowed to use a laser cutter, so all of the pictures that you see have been first mapped out in CAD and then painstakingly measured and cut by hand using a ruler and x-acto knife. Because you have no reason to do this (unless you want to) I have included DXFs for laser cutter and also my original CAD files.

On a high note, this design if done successfully produces a very rigid and robust stool that you can use in your daily life! It has been stress tested and shows no signs of strain or weakness up to 200 pounds. I also got a historic perfect score on this assignment and have been admitted into my major!

With all of that out of the way, lets get designing!

-Cardboard

Realistically, in order to make the full scale stool you need a flat, unblemished piece of cardboard that is at least 4x8ft, but this is super huge and an absolute pain to transport. Here is a picture of my friend with this cardboard. If you don't have cardboard this big, the best place to look is an artist hobby store. This design can also be made from multiple pieces of cardboard glued or otherwise attached together. It can also be scaled to use the largest piece of cardboard you can find!

-Xacto Blade (or laser cutter if available)

It is very important to have many spare blades and to switch them out regularly if you plan to cut this out! I used at least 20 blades on my large scale stool. Cutting it out manually is a HUGE pain and using a laser cutter is infinitely preferable.

-Metal Ruler, 18inch or meterstick preferred

This metal ruler will help you trace the net onto the cardboard and also will help you make straight cuts with your xacto. If you are making the full size it might also help to use a very long piece of extruded aluminum or other long straight edge in order to make sure your sides are true.

-Cutting Mat

Any sort of regenerative cutting mat is good- the bigger the better!

Carefully follow this net and trace the 3 separate shapes onto the paper. All the marked dimensions are crucial, but the tabs can be a little more lose. The diagram I attached here is completely to scale, and I have also attached DXFs if you want to laser cut this out and my original CAD files if you want to see those as well. Take your time and constantly verify if your angles and lengths are correct! if not, you will be in for a very bad time. This step usually took me around 3-4 hours when I was doing it manually.

Once your net is traced, carefully cut each of the lines with your x-acto knife and your ruler. Be careful not to hurt yourself or cut incorrectly! When the main shape and slots are cut out, use your ruler and the blunt end of your x-acto to crease the edges you will fold. This will help the folding step significantly as well as making your stool look nicer. The bad news is that this step will probably take around 4-5 hours if you do it manually... Good luck!

Follow this YouTube video on how this stool is folded.

Yay! After all the trials and tribulations, the stool is finished! Go show it off to your friends! But like any design, it isn't done yet. The next step is to put your own spin onto my design- make it simpler, make it more difficult, using my base, anything is possible! Or, if you're like me, you're sick of cutting cardboard and decide that it is good as it is.

Thank you for reading my instructible! Good luck on your own design journey!