Automatic Watch Winder

thingiverse

Human: Automatic watches are a great option because they don't require batteries; however, to keep them running you need to wear them. This watch winder is designed to wind three automatic watches so they're set to the correct date and time when you're ready to put them on. The design of the watch winder was driven by using spare parts I had in stock including a NEMA 17 motor, an Easy Driver, some bearings, 8mm rod, velcro, 3mm machine screws, Arduino Uno, Relay, Fan (to cool the driver) and 2020 from an old 3D printer (I don't have space for it). I'm still working on this project (which was more challenging than I anticipated) so some elements have been refined, while other elements still need to be tuned and perfected. Challenges Addressed: 1. To be able to hold watches of various strap sizes - the watch holders are spring-loaded. 2. Noise reduction - I reduced gear noise significantly by having two flange bearings at each end shaft. The original design was going to have side bearings to keep the gears compressed, but the cantilever design works well with double bearings on each shaft, eliminating play in the gears. 3. Gearing itself - the original design had standalone gears; I integrated the gears into the watch holder. 4. Where to place the electronics - the electronics were originally in a separate project box; now they're integrated into the unit. 5. Keep the stepper motor unpowered when idle (added a relay module). 6. Dissipate stepper heat (used a fan and a heat sink). 7. Some watches wind clockwise, some counterclockwise, some unidirectionally (script reverses). 8. Printable with minimal support (all but electronics tray). 9. Standoffs were originally built into the electronics tray. Closed Concerns: 1. Lid for electronics box - three-part now enclosed. Outstanding Concerns: 2. Rotary Encoder Programming - If you look at the program, you'll find that the rotary encoder script has a bug in it. The rotary encoders increment upwards but don't go down (I'm only executing the else part of the statements). 3. Replace some PLA parts with ABS parts for strength. 4. Replace a bad rotary encoder. 5. Consider a direct gear-reduced motor as opposed to a stepper (I have a 3rpm motor in stock @ 12v). 6. Find the sweet spot between "winding" and "sleeping". Materials: 8mm rod x 2 5V-One-1-Channel-Relay-Module-Board-Shield Geeetech-Stepper-Motor-EasyDriver-step-motor-Driver-A3967-Driver-Board-Arduino ATmega328P CH340G UNO R3 Board 12v power supply 1-2 amps 2020 - 300mm x 3 Female 2.1x5.5mm DC Power Plug Jack Adapter Connector for CCTV Male Pin Dupont Connector 2.54mm Pitch (used for + - bus) Dupont Jumper wire 8mm Bore Diameter KFL08 FL08 Pillow Block x 4 KY-040 Rotary Encoder Module x 2 20/20 nuts Compression springs x 9 Various 3mm machine screws Various 3mm metal screws