Make Gears With Turtle Art

 

You can code gears with Turtle Art! If you have a fabrication machine such as a 3D printer, laser cutter, or CNC machine you can download the SVG file from a Turtle Art design to fabricate in your material of choice. Here is how I made these gears—5 and 10 inch in diameter—with a Fox Alien CNC machine.

Code in Turtle Art

You can save this image to your computer, then drag it into the web Turtle Art window. The code should appear when you drag it in. (Click the image to get the original version before saving it.)

If for some reason this is not working for you below is the Turtle Art code you can recreate.

To choose the number of teeth you want on the gear change the number connected to the "store in box 1" block, right under the "clean" block. The rest of the code will automatically adjust the number of repeats and the necessary arc sizes to make the gear. The code works for gears as small as 8 or so teeth but seems best for sizes from 12 to 36.

Download the SVG

Click the hamburger (3 lines) on the lower right and choose "save as svg," then choose hairline as the type. This file can be imported into any fabrication software and resized to the dimensions you want. For 3D printing you can import it to Tinkercad. You will have to figure out how to get the hole in the exact center. For a laser cutter I use Adobe Illustrator to prepare files. Below I will detail how I prepared the file for a CNC machine.

Prep for CNC

To prepare a file for a CNC machine I am using web based Easel. I set the machine to a Fox Alien 4040-XE with a 16 inch maximum carving surface. I have access to a Carvey as well but it's too small for the 10-inch larger gear I want to make. In Easel I set the material size and thickness, and choose a 1/16 inch milling bit so the corners will be more precise. I import the svg file by clicking Project > import svg, then change the cut depth to the maximum possible so it will cut all the way through the material. I add a small circle in the center of the gear so I don't have to figure out the center by hand. 

For the Fox Alien I can download the gcode file to an sd card and run the file from there so I don't need to keep a computer tethered.

Assemble the Gears

My second gear had 18 teeth so I sized it to half as big as the 36 tooth gear, or 5 inches in diameter. I secured them to a board with wood screws, with a small space between them so they can move freely. The teeth mesh very smoothly so the 70 degree angle down the side of each tooth seems good. If you make some gears please leave a comment!