High Quality Functional Paper Gears for Your Machines

I needed gears for several projects. Actual metallic gears require milling machines (Manual or CNC type), wooden gears require bandsaw while other methods require laser cutters, 3d printers, etc. These machines are expensive, require skill and time for making gears. If you prefer purchasing ready made gears then also they come at a premium price. If you ask for customized gear the price is even higher.

So I came up with a method of making gears out of paper using a process that not only eliminates expensive machines but also reduces overall time and cost of gears. In addition to above, the method makes you independent in gear manufacturing. The gears are fairly accurate and are comparable to gears manufactured by any of the above methods. They should serve most of your requirements. The gear might break in demanding applications but then you can easily replace it with another one! Time required may seem to be a little more but if you consider overall time required and other advantages this time is far less than required for procuring gears by other methods.

Why I used paper?

Paper is often overlooked as a potential engineering material due to its use in arts and craft projects. But if used properly it has great mechanical strength comparable to wood (plywood more precisely) and plastic. The only major disadvantage is its susceptibility to water as PVA glue is used. Even then it is a potential engineering material currently being used commercially in making kitchen tops, outdoor tiles for buildings, etc.

What you will need?

1. A computer with inkscape installed (I used inkscape as it has a very convenient gear extension and is free. Otherwise several good online gear template generators are also available. Two links of such online generators are given below)
   
   • https://woodgears.ca/gear_cutting/template.html
   • http://geargenerator.com/#200,200,100,6,1,0,0,4,1...
2. A printer
3. Something to cut paper like a pair of scissors or paper cutter, cutting mat, etc.
4. Glue stick or PVA (I preferred glue stick as it does not warp paper. Actually glue stick is PVA with less water content as far as I know)
5. Hand drill machine
6. Sandpaper and/or file
7. Spray paint can

Time Required: 6 to 24 hours depending on your skill, size of gear, thickness of gear, thickness of paper used, etc. You will also need time for adhesive to completely dry up.

Step 1: Creating Gear Templates

Follow these steps:

1. Start Inkscape
2. Set document properties to:
   
   • A4 in Portrait
   • cm as units
3. Goto Extensions>Render>Gear
4. Set first gear properties as follows and click apply:
   
   • No. of Teeth: 20
   • Circular Pitch: 10 (same for both gears)
   • Diameter of centre hole: 10
   • Units: mm
5. Without closing above window, set gear properties for second gear as follows and click apply:
   
   • No. of Teeth: 10
   • Circular Pitch: 10
   • Diameter of centre hole: 10 (can be changed)
   • Units: mm
6. Close above window. You should see two gears as separate objects.
7. Create tiled clones. You might want to first position your gear objects at convenient position so that all clones come inside the printable area.
8. Use following properties for creating first gear clones:
   
   • Simple translation
   • 4 rows, 2 columns
   • Click create
9. Use following properties for creating second gear clones:
   
   • Simple translation
   • 7 rows, 1 column
   • Click create
10. Now save your template as .svg and .pdf (without scaling)
11. Print multiple copies of your template on 100gsm A4 sheets. Number of hardcopies depend on the thickness of gears you want.

Step 2: Fabricate Your Gears

Use the following steps for fabricating your gears:

1. Cut individual gear pieces. This is the most time consuming part that requires a lot of patience. But if you have patience it is fun too.
2. Now paste these pieces on top of each other using glue stick (for small gears) or PVA (for larger gears). Align using your own judgement. Please note: that you need not worry about slight misalignments as they will be automatically adjusted when you will file the gears.
3. Keep some flat weight and leave overnight.
4. Now you can file the gears for imperfections. Riffler files or emery paper of 400 number will do the job. The misalignments will auto-adjust.
5. Drill the centre hole.
6. Finally, spray paint your gears. Safety note: Please use eye protection and gas mask.

Your are done!

If you don't believe in the quality of gears let me ask you to drop your finished gear on a table or on floor. You will love the sound of your gear.

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