$12.00Electromagnetic Pendulum Clock

myminifactory

This is an electromagnetic powered desk clock. It uses a simple electromagnetic pendulum driver that can be purchase for around US$4. Preliminary estimates show that it should run for more than a year using two AA batteries.   The design is loosely based on my stepper motor desk clock with an added pendulum. The clock was sized to support a 10” (250mm) pendulum with a one second period. The overall size is 11.2" (284mm) wide, 13.8” (350mm) tall, and 5.9” (150mm) deep. The clock has two dial sizes in both traditional Roman numerals and simple numbers. The large 7.7" (195mm) dial needs a printer size similar to a Prusa MK3S (250x210mm) or an Ender 3 (220x220mm). The smaller 7.0" (178mm) dial allows the clock to be printed using a Prusa Mini (180x180mm). Total print time is around 70 hours and 1kg of filament.   A preliminary video of the clock is at https://youtu.be/hA_TA9gM4SU Assembly videos will be available soon.   The 50 page assembly guide can be downloaded from https://www.stevesclocks.com/sp7 if you want to see the instructions before purchasing the design. You can also find a discussion forum at https://www.stevesclocks.com/forum if you have any questions during construction. There are only a few well hidden non-printed parts. The most important componant is the pendulum drive module. The proper unit to fit into the base is described in the assembly guide. The remaining parts are music wire for the arbors and a few screws. If you have built any of my other clocks, then you may already have most of the required parts.   Here are a few links to the pendulum drive module. I will try to keep this list updated as it changes. In the US: https://www.ebay.com/itm/353835662177  (US$8.56, estimates 1 week shipping) https://www.ebay.com/itm/224311666387  (US$11.95 with discounts for multiples, estimates 1 week shipping) Shipping from China: https://www.ebay.com/itm/334196463736  (US$3.30, estimates 5-15 weeks shipping, but usually 3-4) https://www.ebay.com/itm/353575631542  (US$3.43, estimates 6-16 weeks shipping, but usually 3-4) https://www.ebay.com/itm/333724361203  (US$6.92, estimates 2-3 weeks shipping)   22-Feb-22 Update: Added an additional dial with a curved arch similar to the top of the mini front dial. Made some minor fine tuning to the back frame standoffs to minimize the need for a long reach drill bit. A minor typo was fixed in the assembly guide.