I designed this instructable with the idea of providing a simple answer to a couple problems. The primary problem is finding a use for good paper that gets thrown away every day all over the world, when it can be used to make paper models instead. The other problem I aim to solve is the need for a mockup/test model that sometimes crops up before one goes all in with a project or model. This instructable will show you a eco-friendly and cheap way to make models out of paper whether you are just looking for a fun afternoon project or you need to test out how something will look before building or 3d printing it. With the explanation out of the way, lets get started!
Step 1: Choose Your Model Source
The first step is to find what you want to make. There are two great places I can think of to do this. The first is thingyverse. I have found free 3d models for many different things here, so there is a excellent chance you can find a model of what you want to make too. The second option is to make your own model using sketchup (you could use any 3d design software, but sketchup is free). I'll show you how to do both, although I admit I like the second method better, because it allows for more flexibility. If you are interested in making a sketchup model, continue reading. Otherwise, skip to step 4 to learn how to make a thingyverse model into paper.
Step 2: How to Make a Model in Sketchup
First things first, you will want to go to https://www.sketchup.com/ and navigate to the "products" dropdown menu and click "sketchup free" under the "for personal" section. Next, click "start modeling". It will ask you to make an account or sign in. If you already have an account, sign in and wait for the rest of us. If you do not have an account, you will need to make one. Then agree to the license terms on the modeling page. Oh yeah, and while you are at it, click the sketchup guy and delete him unless you have a particular use for him. One of the things I like about sketchup is the fact that it is so simple and easy to use. If you just want to make a simple object, all you will need is the straight line tool. Its the one on the left panel and it looks like a pencil. For those of you who like more complex and fancy shapes, you can select the curvy line tool in the pop out menu that shows up when you click the pencil. However, I will warn you in advance that unless you have incredible stores of patience and/or skill, you would do best to stick with the straight line tool. If you do decide to make a model using the curvy line tool, have fun trying to fold it and waiting for the program that I will introduce shortly to make the model flat for you.
Once you have your tool of choice selected, start drawing! For purposes of simplicity, I will illustrate how to make a house, but the sky is the limit for what you can make with this program. Start by clicking the corner where the red, blue, and green axes meet. Take note of those. They will be one of your most helpful references when using this program. Next, drag your line along one of the axes to the desired length (which is displayed int the bottom right corner). If you have a specific dimension in mind, then you can type it in by hitting the colon/semicolon key, deleting anything in the "length" box, typing in your desired length in inches (or feet if its that big) and hitting enter (for whatever reason, this trick does not work with letter keys, and I haven't tried the number and other obscure keys yet). It will then automatically make a line of that length for you. With that finished, you can then proceed to make a box. One other tool that will be useful while you are doing this is the camera rotation tool, represented by 2 arrows chasing each other around a pole at the bottom of your left hand tool panel. Once you have a box, go ahead and draw intersecting lines on the top of your box at the half way points of the length and width. Sometimes if you hover over the midpoints of the lines a light blue circle will appear and the word "midpoint" will appear. Next, draw a line where the two lines intersect (should be dead center) and draw it up along the blue axis until you have reached the desired height of your roof. Picture 5 shows where you should be if everything is working correctly. The last step is to draw lines from each of the 4 corners to the middle line you just made. If you are really picky about simple and clean models, you can delete that line after the roof is done.
At this point, you can continue on from here and make windows and doors and gables and what have you, but I don't want this instructable to turn into a sketchup tutorial. There are some videos on youtube that do a great job of explaining how to use the other tools, should you care to add to this basic house design. But hey, let me know in the comments if a sketchup tutorial would be something you would be interested in...
Step 3: Saving Your File and Downloading It As an STL
The next step is to save your truly splendid 3d creation in the generic sketchup folder by clicking save, and then selecting the sketchup folder, naming your project, and then clicking save here. After that, you need to download it as an STL by clicking the folder button, then clicking "export" and then selecting STL under the direct download section. Unless I am mistaken, it HAS to be an STL in order for the paper program to be able to work with it. The next step will be to download the paper program that makes all the unfolding magic happen, but first, I will explain to the folks who decided to find something off of thingyverse how to get where we are now. If you are not interested in seeing that process, skip to step 5.
Step 4: Downloading a Model From Thingyverse
Once you have navigated to https://www.thingiverse.com/, start searching for what model you want to make in paper. Then, you can check it out using thingyview, and if you are happy with it, go ahead and click download. For simplicity and illustration purposes, I've selected a simple house model. Usually its ok to just click download all files, but if you chose something more complex and you only want part of it, sometimes the creator will make the project into multiple files, which you can scroll down the page and click "thing files" to view.
Step 5: Downloading and Using Pepakura
Now that you have the 3d file that you want, the next step is to download pepakura, which you can do by going to https://tamasoft.co.jp/pepakura-en/download/index.... Its a perfectly safe and free program that allows you to make foldable paper models from 3d files. After you have downloaded it, open the pepakura designer 4 program. Next, click on "file", then "open", and find the 3d file you downloaded earlier. In my case, the house model from thingyverse. Click ok, next, no flip, etc. Nothing needs to be changed. Once you have the raw model in front of you, the fun part starts. Click unfold. It should do it pretty quickly, or in my case instantly, because it is such a simple model. For larger or more complex models, it will take way longer. If for whatever reason you don't like how the flaps are set up, you can edit them in the 2d menu. At this point, it is just a matter of ctrl+p and cutting and gluing your model! You should be able to use any scrap 8 1/2" by 11" scrap piece of paper in your printer and it will print fine.
Step 6: Troubleshooting
Pepakura cannot find or open my file. What to do?
I have found that unzipping the file and saving it in documents is the best way to save your 3d file. Also double check to make sure the file is STL.
I unfolded my model, but there are a lot of tiny parts I don't need, and I don't like all the flaps.
You can click on individual parts to delete them in the unfold window. As for the unwanted flaps, if you click the 2d menu, and then edit mode, you can select "edit flaps" and trim off the ones you don't need.
I printed out my model on scrap paper, but its too flimsy. It won't stay together at all!
Cardstock is usually better for making paper models, or you can glue a couple of scrap pieces of paper together to make it stronger. If you are having trouble keeping the model glued together, you can try applying a VERY small amount of wood glue instead of using a gluestick for a stronger bond.
I am so confused. My model has a lot of flaps and parts to it and I have no idea where to start. Is there a building instructions tool or something? Help!!!
Luckily, there is a tool to help with this. If you click on the 3d menu button and then click folding/unfolding animation, it will show you how the model can be assembled.
Thank you so much for stopping by to check out my instructable! Feel free to comment and vote if you thought this instructable was a winner!