Drills

• A commonly used machine for cutting gears is a drill. Replace the traditional drill bit with a sharp, cutting bit. You can then take a gear blank, which is a gear without teeth, and cut teeth into it. It is important that you're cutting bit is strong enough to cut the material the blank is made of, as hard materials will quickly dull the cutter in a drill.
  
  

Jigsaw

• Not all gears are made out of metal, so not all machines for making gears have to be capable of cutting through metal. Gears can be made out of wood, and if you're cutting wooden gears you can use wood working tools like a jigsaw or hand held power saw. However, you have to be careful when carving these teeth because if the wood being used is too soft, the gears may snap or wear down too easily.
  
  

Hand Shaping

• It is also possible to shape a gear by hand if you have the proper tools. You can clamp the gear blank down to your workbench and use a hammer and chisel, a hand saw or even carving knives approved for the materials the blank is made of. Some materials, like paper and cardboard gears, almost have to be shaped by hand with scissors and a utility knife due to the comparatively delicate nature of the materials.
  
  

Sanding

• Whether a gear is shaped by hand or cut on a machine, some sanding and smoothing is often necessary afterwards. Use sandpaper graded for the material you're smoothing, starting out with rougher sandpaper and moving to progressively finer and finer grains of sandpaper until the gears are smooth. Burrs and dings can cause friction and damage once the gear is put into the machine, so you want to eliminate as many of these as possible.