Wooden You Love This Automated Perpetual Calendar Hanging on Your Wall?
Troy Hawkins' project rolls through the month and days using three wooden rings.
Years ago, Troy Hawkins (AKA tomatoskins) came across a perpetual calendar that features rings to indicate the month, day of the month, and day of the week in concentric circles. It’s a neat idea, but it’s designed to be manually operated, and he didn’t think he’d keep it up to date if he were to get one.
Naturally, he turned to automation when he decided to create one himself, assembling his own wooden and 3D-printed version that’s actuated by a trio of 28BYJ-48 stepper motors and ULN2003 drivers. Rings are held onto each stepper's 3D-printed spur gear via gravity, allowing them to advance automatically under the control of an Arduino Nano. An RTC unit keeps the date in check, and magnets embedded within each of the gears can be picked up by Hall effect sensors, enabling it to correct itself if the output is awry.
It's an interesting build from a technical standpoint, but perhaps what stands out is how the “technology” is. With the exception of a power cord, concealed inside a beautiful hardwood frame, one might assume its operation was mechanical. A large portion of the project deals with actually constructing the ring sections out of different wood segments. If you were to modify things for CNC and/or laser cutting, you might be able to shortcut construction time significantly!