SP4B: This is my easiest to build clock with a runtime of up to 23 days. The SP4B update is a major refresh to make the clock more reliable. This includes a more efficient gear tooth profile, updated frame, new winding key, plus a few additional updates. All these improvements make the clock more efficient so runtimes of 17 to 23 days are easily achievable. The original SP4 design had a maximum runtime of 21 days. The SP4B update increases the runtime to 23 days using slightly less weight and makes it more reliable.

A description of the design update can be found at https://youtu.be/6UzRCrHQSnw

A video of the original SP4 clock and its smaller sibling can be seen at https://youtu.be/djp73Q6tXZA  The larger clock is shown about halfway into the video.

Go to https://www.stevesclocks.com/sp4 to download the latest assembly guide. 

Use the forum at https://www.stevesclocks.com/forum to discuss clock making topics or assembly issues.

Assembly is very similar to the smaller version of the clock. They can be seen at

   Part 1 - Subcomponent assembly https://youtu.be/gM1UZuv43u4

   Part 2 - Final assembly https://youtu.be/SawrNzYoE2A

   Part 3 - Debug hints https://youtu.be/uQcfjhecORE

This is a great starter clock because of the simplified construction. Various options are provided with runtimes ranging from 7.6 days to 22.5 days. The longest runtime of 22.5 days is a bit aggressive and the 17.1 day option would be more reliable. The shorter runtimes will be the most reliable and winding a clock every week or two is pretty impressive for a clock that you build yourself. The gears run great when printed using silk PLA.

The list of non-printed components is half the size of my other designs. The complete bill of materials is:

  ~1.2kg PLA filament in multiple colors

  25 6x3/4" wood screws

  6 M3x8mm socket head screws

  22" 3mm metal rod

  6" 1.5mm or 1/16" metal rod

  12' fishing line

  5-10 lb. BBs or lead shot for the weight shell

  5-8 623RS (3x10x4mm) bearings

  4 springs from a ball point pen

  44 pennies for the pendulum bob

Parts can be sourced locally through Amazon, eBay, Ace Hardware, etc. I also have put together some parts kits at https://www.etsy.com/listing/1680180262 if you prefer.

Total print time is around 80 hours. This design needs a printer with a bed size of at least 210x210x150mm. A Prusa MK4, BambuLab A1, Creality Ender3, or other similarly sized machine will work great. 

Multiple clock faces are included with simple numbers or roman numerals. Different hand styles and weight shell sizes are also included.

A smaller version of this clock is also available (https://www.myminifactory.com/object/3d-print-156759) with a 32 day runtime. The lighter weight gears need less energy so the runtime was increased. You have a choice between the larger more visually impressive clock or the smaller more technically impressive clock. Either one would look great on your wall.

Steve

Update 10-Apr-22: Refreshed gears 3 and 4 to add a slight helical angle so gear 3 pushes away from the escapement. This change will significantly reduce the possibility of the escapement stalling and stopping the clock. The gears affected are gear3_64_15_1.stl and gear4_70_??_??day_1.stl. The file names have a "_1" suffixe added by MyMiniFactory to indicate a revision. It is worth downloading these gears and re-printing them even if you have a functional clock.

Update 02-Sep-23: Added Rev 2 updates to completely isolate the escapement from gear 3. This is an even better fix than the previous helical gear update and is recommended for all new designs and as a retrofit for existing clocks. Also gear 4b has an optional set screw for easier assembly. All new files have a "rev2" suffix in the file names. A complete description is in the rev2 addendum pdf. The files can also be found at https://www.myminifactory.com/object/3d-print-wall-clock-rev-2-updates-321782

Update 19-Feb-25: Major update and rename to SP4B. A new more efficient gear tooth profile is used to allow 23 day mode to be reliable. The frame is updated to include alignment tabs. A better winding key design was added. Three extra bearings were added to minor wear locations, although these might be optional.