Pocket Watch Case

thingiverse

Do you like watches? Do you like history? Is the post-WWI/WWII social-political-economic system too depressing to handle on a daily basis? Return to the golden days of the industrial revolution with this pocket watch holder! With this timepiece you can finally live in a time when Habsburgs still rule Austria and Communism is nothing but a German fever dream! Role-play as the son of a middle class American family who has been conscripted to fight in the Great War. You were just told by your officer that it is imperative to bring a working wristwatch for the front lines and your mom happened to have a spare ladies' pocket watch. You run down to your 3D-printing fabricatorium and desperately search Thingiverse for a suitable case. Lucky you, you have come to the right place! [Introduction] This "thing" includes designs for a case for converting pocket watches to (men's sized) wrist watches. This case was designed to fit an open-face pocket watch with a size 0s (1 1/6 in) diameter movement. The resulting case had 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 was tested using an Ender 3 and standard Cura settings at 0.06 mm z-height with the default 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 included. There is room to both expand and shrink at least a couple millimeters along all dimensions. The number of crown cutouts can be customized. Lower numbers of crown cutouts increased 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 asymmetric features unique to your pocket watch (e.g. the hinge or release pin). [Mechanical considerations] It is important to note that most vintage pocket watches have poor shock-absorption. 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, however the degree of protection remains untested. The gray build pictured in the attached photos was tested over a period of 6 months. The watch did not show any inaccuracy or other signs of deterioration 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 much 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 the modern technological marvel that is 3d-printing 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 in general and watch manufacturing in particular will help back up your conspicuously pretentious choice to wear a 3d-printed watch to prom. Whether you want a way to display your family heirloom on your wrist or you are just getting into horology, this is a fun project that is definitely worth a try.