Picture of How to Build Working Gears from Junkmail and Cardstock
Junkmail Gear

This step by step tutorial will show you how to print, cut out, fold, and construct a gear to get you started building your own papercraft mechanical devices. There is still some small problems with the design, but I'm trying to balance ease of construction with functionality.

You will need:

1. A Laser Cutter or X-Acto Knife.
2. A T-Pin, Straight Pin, or Push Pin at least 5/8" in depth, (regular pushpins are too short and map pins bend too easily).
3. Stiff paper, Brochures and Junkmail like Restaurant Menus are a good choice as long as they fit into whatever printer you're using.
4. A half hour of time and Patience, this is very much like miniature model building.

Step 1: Choose your Size

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There is a small, medium, large and extra large gear your can choose from for now.

I'm including 3 different file types to get people started. A zip file containing the parts in an EPS format for laser cutting, a copy of each one as a PNG file, and an illustrator template file (by popular request, I've also just added an archive with the files as SVGs, Inkscape away!). Remember that when you use the template file, all the objects are located in the symbol library, along with prefabs to help make your own constructions.

If you are going to cut it out with the laser cutter, skip to step 5.

I've found that the larger the gear, the less slippage you will have in the system overall, but it will take more time to construct a larger part. Here are your choices:

1. Small Gear
1/2 piece of paper
Teeth - 8
Inner Diameter - 60mm

2. Medium Gear
1 piece of paper
Teeth - 10
Inner Diameter - 75mm

3. Large Gear
1 piece of paper
Teeth - 12
Inner Diameter - 105mm

3. Extra Large Gear
2 pieces of paper
Teeth - 15
Inner Diameter - 330mm

Step 2: Print the Gear

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Once you've selected and opened the gear you would like to get started with, print the file out on a stiff stock of paper and optionally tape it to your cutting surface.

Use junk mail or restaurant menus, anything lying around that is stiffer than normal computer paper and can fit in your printer.

Step 3: Score Folds

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For any dotted lines on the image, I highly suggest scoring these with a ballpoint pen or any semi-blunt object you have lying around. After a little practice, I've been able to use the back of my X-Acto Knife to score my folds. This will make it much easier to construct the gear once you're done cutting.

Step 4: Make all the cuts

Using the Exacto-Knife (with a decently sharp blade), cut any solid lines inside the gear first, then cut everything out of the cardstock. On the inside, make sure you pop out any of the inner tabs as they will be hard to get to after you start putting everything together.

You should now have both sides of the gear cut out, now lets get to construction!

Step 5: Connect the Caps

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Fold the center tabs inward on the bottom piece and push them through the groove you cut on the top piece. Make sure that all the tabs are pointing straight up through the top piece and that the printed side is facing out for both caps.

Step 6: Fold in Teeth

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Fold all the remaining scores on both sides. Push the tabs at the bottom through the top slots.
Make sure that the tab is on the inside, they should be held in place by the right angle they create, and the designed to also add structural support.

Step 7: Poke Holes

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Use a thumbtack to poke a hole at the center pivots on either side. This is to ensure that the gear doesn't go off kilter when it begins to turn.

Repeat the steps and test it out on your wall surface or corkboard. These gears can stack on each other, so if you have a pin which is long enough, try making multi dimensional mechanical devices.
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IceDani4 years ago
Thanks a lot for the how-to! I managed to make one myself, it's pretty easy, even though i had a bit of a problem with folding the teeth. What else can i use instead of the thumbtack? I don't have one of these :(
Travpena5 years ago
where is the PNG files?
On this step (Step 1), if you click on the thumbnails of the gears (five of them), the image will be in the bigger preview above the thumbnails. Click on the italicized i on the top left of the bigger preview, click on "Original Size" in the left menu, and you should be able to save the png file that way.
Travpena5 years ago
where is the PNG files? (not a double post its been a mouth and no ones got back to me)
abarat5 years ago
Thank you!
I have a question for you, is it possible to use these deigns to make about 100 gears that all move at once? 
Riblets (author)  abarat5 years ago
 for many gears, you need something with involutes. Paper gears wouldn't be the best for that situation.
Awesome! Now to build a paper Curta!
this is absolutly perfect for my time project in which i gotta make a geared foliot clock
magic_snjor5 years ago
 This perfect, I'm working on a chair sculpture and  was stuck on the gears, Thanks sooo much this is amazing  
You could always use a long enough rivet in place of the thumbtack.
jayteerox6 years ago
man u really bite ur nails...
I thought you were talking about your avatar then...
Riblets (author)  jayteerox6 years ago
better than smoking :D but I agree, i need to cut it out.
I saw these bad boys in action they are great
Iridium76 years ago
mine keeps on printing to the side of the paper and get cut off and disoreintated, can you please help?
Iridium76 years ago
for exto cutting what file do I download and what software do I need?
Riblets (author)  Iridium76 years ago
The PNGs should work, but so will the ESP files (which if you're on a mac, opens as a PDF)
It doesn't work on my computer. it asking me for a program but I don't know what program It needs.
Riblets (author)  Iridium76 years ago
Use inkscape for a free solution, or illustrator if you have it. The SVG files should work in either program:

srilyk6 years ago
That's pretty awesome! It makes me want to build some sort of paper clock :D
vbanaszak6 years ago
This is awesome! Thanks for making it available and for all of your hard work to make it available in so many formats. I can't wait to give it a go.
DukeJoke6 years ago
Nickelplate6 years ago
Great! I have access to a laser cutter but never knew what to do with it...
Edgar6 years ago

For the design problem;

Get here:
Ando look for the Interactive Gear Template Generator
Oh awesome, I am so excited that page exists!
heybobby!6 years ago
OH YEAH!!!!!
Southpole6 years ago
cool, and you actually get them running smoothly? i tried to construct planetary gears as found in an automatic transmission from paper gears a while back, but the thing never ran smoothly, immediately jammed crumpling the gears
Riblets (author)  Southpole6 years ago
A little distance between gears is an enormous help. I put around 1 to 2 mm distance between the gears so that they don't lock up.
SoapyHollow6 years ago
wow. Now I *really* want a laser cutter.
mycroftxxx6 years ago
One possible simple method of reinforcement for the gears would be styrofoam. Printing and cutting out an extra piece of cardstock to act as a stencil for a given gear would be fairly easy with a hot wire foam cutter like http://www.instructables.com/id/Hot-wire-foam-cutter/?ALLSTEPS. The overall design and construction method might be a little different, but it shouldn't be that difficult.
You could just use the spray insulation in a can to fill the interior and trim the excess after it expands and hardens.
Dr_Acula6 years ago
Great Instructable!

Check out http://woodgears.ca/gear_cutting/template.html for involute gears that will run smoothly. Click on the "two gears" checkbox. Change the number of teeth if you like. Then print it out on a piece of paper. I've built small cardboard gears and also wooden gears using these templates from 10cm in diameter right up to 1.2 metres in diameter.
randofo6 years ago
Very cool. I look forward to attempting to make complex paper gear mechanisms.
du6 years ago
A zip file containing the parts in an EPS format for laser cutting, a copy of each one as a PNG file, and an illustrator template file. Maybe I'm slow, but I only see the EPS files and a ".ait" file (that Inkscape doesn't recognize). No PNGs or .ai files.
Riblets (author)  du6 years ago
Oh, well the ait file is an illustrator template file, not an illustrator file :/ let me see if I can get an inkscape specific filetype ... the less cost the better.
Riblets (author)  Riblets6 years ago
PKTraceur6 years ago
Can we get this on windows? It seems to only be on Mac OS. Perhaps an Inkscape or the GIMP files, please? Perhaps a PDF? -RoAr
agis686 years ago
Excellent idea and project... I never knew that u could make a whole tool by that kind of gears (like the site paperreplika.com) I am amazed for what u done. Now some improvements...I wonder if you could use aluminium to have more hardening results... Here in Greece in modelist stores u can find a paper which is made by wo layers. One layer is aluminium and the other side is paper...(i dont know how its name is but iam sure where to find it in Athens)Maybe this is the perfect paper for that kind of job...I will try
DIYDragon6 years ago
If you painted some of these up nice they might make cool wall art! : ) Nifty project.
Zorink6 years ago
If you have A LOT of free time you can make an working clock!
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