Trammel of Archimedes (aka Ellipsograph or Nothing Grinder)

thingiverse

The Trammel of Archimedes, also known as an "ellipsograph," is a classic toy illustrating geometry and mechanical motion principles. This intriguing device traces perfect ellipses when used correctly. You can find an animated demonstration on Wikipedia at this link: http://en.wikipedia.org/wiki/Trammel_of_Archimedes. While my design reflects various well-known versions, it has fascinated people for centuries. The handle boasts a hexagonal hole for inserting a shortened pencil, making ellipse drawing possible. Watching the mesmerizing motion is enjoyable, and you can even print and play with this version of the Nothing Grinder. Please note that this model was designed for printers capable of support material like Stratasys BST. The handle, rail, and rivets don't require support material, but the base does. If your printer lacks support capability, simply modify the base design for easy printing. Assembling the Nothing Grinder is a breeze. Just print two rails, two rivets, one handle, and one base. Slide the rails into the base, position the handle with each hole fitting onto the corresponding rail, and insert the two rivets to lock the handle to the rails. Now you're ready to play or draw ellipses!