3D Printed Post Modern Grandfather Clock

Projects can often spiral, not down or up, but out. For [Derek] he started playing around with a 3D printed escapement mechanism and thought it was a wonderful bit of engineering. But with a simple drum and weight, it only had a runtime of a few minutes. What started as a simple “can I make it run longer” spiraled into a full-blown beautiful grandfather clock.

A gear drive, a ratcheted winding sprocket, and a ball chain gave the clock about one hundred minutes of runtime. Adding a recharging mechanism was fairly straightforward. The weight automatically rewinds with the help of an ESP32, a motor, and some limit switches. While an ESP32 is absolutely overkill for this simple project, it was cheap and on hand. A quick hall effect sensor to detect the pendulum passing made it into a proper clock. Considering it’s a printed plastic clock, losing only 2-3 seconds per day is incredibly good. The whole thing is wrapped in a gorgeous wood case with a distinct design.

Surprisingly, everything was designed in OpenSCAD and Blender. [Derek] includes some great tips such as cleaning out the ball bearings to make them run smoother and suggestions on how to make a plastic clock move without binding. Clock making is a complex and sometimes arcane art, which makes watching the process all the more interesting.

The Hour Of The 3D Printed Clock Draws Nigh


Many have tried, but [Christoph Laimer] has succeeded in designing a working, (relatively) accurate clock nearly completely from 3D printed parts. Every gear, pulley, wheel and hand of [Christoph’s] clock is printed. Only a few screws, axles, a weight, and a string are non-printed. Even the crank to wind the clock is a 3D printed part.

[Christoph] designed his clock in Blender. It took quite a bit of design work to create parts that would work and be printable. Even more work was involved in printing over 100 failed prototype parts.

One might think that [Christoph] is using the latest  printers from the likes of Makerbot or Utimaker to achieve this feat. It turns out he’s using a discontinued Rapman 3.2 printer. Further proof that even “older” printers are capable of great things! [Christoph] does run his printer rather slowly. Printing a single gear with 0.125 mm layers and a 0.4 mm nozzle takes him 2 or 3 hours.

Mechanically, the clock is gravity powered with an anchor escapement. Rather than a pendulum, [Christoph] chose to use a balance wheel and hairspring assembly to govern the escapement.  Even the spring is printed from standard PLA. The weight is suspended from a pulley block. The clock isn’t particularly efficient. 70cm of height will run the clock for only 2 hours.

[Christoph’s] clock has proven to be accurate to within 1/4 second per hour. He hasn’t provided temperature stability data – but being PLA, we’d suggest not getting it too hot!

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