Pocket Watch Case

thingiverse

Do you enjoy collecting timepieces? Do you appreciate historical events? Are the social and economic conditions of the post-World War I and World War II era too bleak to face every day? Go back in time to the industrial revolution's golden age with this pocket watch holder! With this timepiece, you can live in an era where the Habsburgs still rule Austria and communism is nothing more than a distant memory. Imagine yourself as the son of a middle-class American family who has been conscripted to fight in World War I. You've just received orders from your officer to bring a functioning wristwatch to the front lines, and your mom happens to have a spare ladies' pocket watch that you can use. You rush down to your 3D printing workshop and frantically search Thingiverse for a suitable case. [Introduction] This project includes designs for converting pocket watches into (men's sized) wristwatches. The case was designed to fit an open-face pocket watch with a size 0s (1 1/6 in) diameter movement, resulting in an external diameter of 38 mm. There are three versions fitting strap widths of 20 mm, 22 mm, and 24 mm. The pocket watch pictured was purchased on eBay. [Print settings] This design was tested using an Ender 3 with standard Cura settings at 0.06 mm z-height and a 0.4 mm nozzle. A z-height of 0.1 mm produced similar results. A standard 1.75 PLA filament was used following the manufacturer-specified 215 degrees C nozzle temperature (see gray build in photos). A second PLA filament at 190 degrees C produced similar results (see white build in photos). These prints were achievable with or without supports. Printing times ranged from 1-4 hours. Printing orientation was the same as defined in both the STL and CAD files. Fusion 360 files are included. There is room to expand or shrink at least a couple of millimeters along all dimensions. The number of crown cutouts can be customized. Lower numbers of crown cutouts increase the fall-out force necessary for both inserting and removing the pocket watch from the case. Individual crown cutouts may need to be modified to fit unique features on your pocket watch. [Mechanical considerations] It is essential to note that most vintage pocket watches have poor shock-absorption capabilities. It may be necessary to modify the design with more cushioning to protect the balance wheel (see "pare-chute", A.L. Breguet). The case side mounts have been designed with shock-absorption in mind, but the degree of protection remains untested. The gray build pictured in the attached photos was tested over a period of six months. The watch did not show any signs of deterioration or inaccuracy after real-world use. The watch was worn in both indoor and outdoor settings, including cooking, bike riding, and exposure to extremely cold temperatures down to 20 degrees F. Simulations were performed in Fusion 360 to compute the theoretical failure thresholds. The watch fall-out force threshold was determined to be 7 lbs. The strap pull-out force threshold was determined to be 10 lbs. [Assembly] The edges parallel to the watch straps were prone to tearing more than those perpendicular. When inserting the pocket watch, push it into the pocket perpendicular to the watch straps first, then carefully fit each of the sides in one-by-one. It is better to bend the base rather than putting pressure on the attachment point. It is possible to assemble it without cracking the sides (PLA), so if you can't get it on the first few tries, set it aside for a few days and try again! [Conclusion] This was a fun build that combined modern technological marvels with old pocket watches that desperately need attention and care. The resulting watch was suitable for casual wear due to the plastic case. It is possible to use a leather strap for formal wear as a statement piece, although background knowledge into horology will help back up your choice to wear a 3D-printed watch. Whether you want to display your family heirloom on your wrist or are just getting into horology, this project is definitely worth trying.