Variable Pitch Involute Gear Designer

The effective kerf of our laser cutter on the wood we are using for these gears is accounted for in the design and the center hole is designed for gears to spin reasonably freely without wobbling much on a 1/8" dowel. Set up your gear:
  1. Choose number of teeth.
  2. Choose diametral pitch (number of teeth that could be lined up on the diameter of the gear; smaller value means a bigger gear for the same number of teeth and larger teeth). Interacting gears must have same diametral pitch.
  3. Select whether the teeth should be on the inside or the outside.
  4. WRITE DOWN the pitch radius for your gear. You will need this to layout where the gears are.
  5. The gear will export with some size based on the viewing window. WRITE DOWN the value after "Rescale the svg output ...".
  6. MAKE SURE all of gear shows in the window.
Easy export (laptop and maybe Android devices with Firefox browser):
  1. Give your file a useful name.
  2. Click the Export button.
Harder export (iPad using Safari)
  1. Tap the 3-horizontal-lines icon in the top right corner of the applet.
  2. Tap on Download As and then select .svg from the pop-out.
  3. The file will open in a new window. Use the Share icon to send it to your Google Drive.
  4. Add the .svg ending to the file name.
Once you have an .svg file:
  1. Open file with Inkscape on a computer that can be connected to the laser cutter.
  2. Select the gear, change the units to mm, lock the width and height together, and resize as specified in the applet below.
  3. Use Extensions -> Lasercut Path to Open in Visicut.
  4. In Visicut, set the Mapping to Map by Single Property and then check the blue (which should have defaulted to Cut) OR if only the gear shows up in your file, choose Cut Everything.