Mechanical Moon Phase Calendar

cults3d

A mechanical device that will track the phases of the moon and the day of the week. Turning the crank clockwise one revolution each day is all that's needed. I got interested in moon phases when I learned that they affected fishing, and I wanted a more physical way to track it. Worked on this for a few years now. Not so much the model itself but the math involved. Redesign after redesign has led to this first final model. I plan to add to and improve this design in the future, but this model will do the job with great accuracy, only needing recalibration after 3 years or so. You will need a paint pen or sharpie to color the display gears and make the other marks in the picture. To build, put the gears on the pegs as seen in the picture. Wait to put the crank on until after you have lined the week and moon gear up with the upper mark. Then put the crank on its peg, alining it up with the lower mark. Lastly, put the caps on the pegs to keep the gears in place. The fit is tight enough that the gears won't fall off, but still loose enough that you can remove the caps to recalibrate the device when needed. When setting and recalibrating the device, use a date with a known moon phase then crank the device forward or back to today's date. For example, today is Sunday, February sixth and I know that Tuesday the second was the new moon. I would align the upper mark with the new moon and Tuesday then put on the crank gear (aligning it with the lower mark) and put on the caps. I would then crank clockwise until the week gear showed Sunday.