The Timing Chains - Mechanical Digital Wall Clock

Decorative mechanical digital wall clock is introduced.

Features

• You can make this clock with small 3D printers. Maximum part measures 151 x 90mm.
• Relatively easy to make. Number of printed parts is 42. Chains are partially print-in-place, and connection of links is snap-fit.
• Easy time adjustment.
• Digits are highly visible. Without painting or glueing, it automatically combine white letters and black background on top. The digits are a bit slanted.

Operation

• One minute advance with reset button of micro computer
• Fine position adjustment with reset button while the motor is running
• 10min. and hour digits can be adjusted (rotated) by your hand

From technical point of view, the highlight of this clock is a carry up mechanism that can handle any base of the numeral system. In actual, 10min and 60min carries share the same mechanism. The only difference is the length of the chain.

To design the gears, I used "Precision Gears" addon for Blender, https://makertales.gumroad.com/l/PrecisionGears

Jan 5, 2022 : 12/24h version has been added. Please take a look at the last part of this description.

Mechanism

One of the technical highlights of this clock is the carry-up mechanism that can handle any base of the numeral system. In actual, 10min and 60min carries share the same mechanism. The only difference is the length of the chain.

How to make

You need

• 28BYJ-48 stepper motor and driver board comes with
• Arduino nano or similar micro computer
• Three 2 x 8mm tapping screws
• Soldering iron for plastic welding

How to make

• Some objects consist of several shells (closed polyhedrons). It can be printed out by Cura slicer, butsome other slicers (such as Prusa slicer) can not handle such data properly . In this case, please use online STL fix services.
• Print all parts with supplied posture. Basically all parts can be printed out without support. However, the overhang of "servo-holder.stl" is relatively large, and it may be better to use support for this parts only.
• Change the color between rotors and chains for the visibility of the digits.
• Chains are partially print-in-place. If it does not work well (ex. fuse together), please use separate chain links.
• Chains can be connected by snap-fit manner. Just push together to assemble.
• Connection between parts are basically plastic welding.
• Remove blobs or debris around the parts carefully or the clock locks against the torque of the motor.

Circuits can be enclosed in the case at https://www.thingiverse.com/thing:5145523

12/24H version

12/24H version has been added.

• It is wider than original version (151mm vs 161mm). Use parts in 24h.zip. Changed parts are, baseboard.stl, rotor-h.stl and chain for hours.
• A make of 24H version can be seen at https://www.thingiverse.com/make:999712
• Switching between 12H/24H can be done by just adding / removing 13-0h chain links.

Category: Gadgets