This clock is a functional timepiece that shows roughly the time by rotating a roller chain twice per day.

It works with a simple clock mechanism. The chain is 26 cm long.

Print instructions

Update: I reworked the clock and added some features. The movement can now be removed without disassembling anything. The outer plate of the chain links now fits much tighter. Assemble with some force, either with a hammer or a bench vice.

Because some people are having problems here is a disclaimer: The chain has very small tolerances, please test with a few pieces before printing the whole chain. The Rollers need to roll on the pins and the Outer Plate also needs to go over the pins without much friction.

This clock is a functional timepiece that shows roughly the time by rotating a roller chain twice per day.

It works with a simple clock mechanism. The chain is 26 cm long.

Additional hardware needed:

3x M3 screws 6-10 mm

1x clock mechanism, the shaft needs to be 20 mm in total length, this is the one I bought:
[https://amazon.de/gp/product/B01LXWJFPW](https://amazon.de/gp/product/B01LXWJFPW)

1x Bearing: 10x15x4mm
[https://www.amazon.com/gp/product/B00RWGXNVI/](https://www.amazon.com/gp/product/B00RWGXNVI/)

3x M3 Heat-Set Inserts
 

Printing

Print the following parts:

• 1x Enclosure_inserts if you would like to use heat-set inserts or Enclosure_no_insert if you just want to use screws. No supports, the keyhole in the top has a one layer bridge built in
• 2x Sprocket, the only part that needs supports
• 1x Holder
• 1x Pin
• 1x Lid
• 1x Big_gear
• 1x Small Gear

Chain:

• All the number links 1-12
• 24x CL_OuterPlatePin
• 30x CL_OuterPlate
• 60x CL_Roller
• 54x CL_InnerPlate

Depending on your printer, you might need to sand the links to reduce the friction in the chain. Otherwise, the chain will skip and the time will not be accurate.

Assembly

Chain assembly:
Print some test pieces and test the fit first. The CL_OuterPlate should fit on the pins with some force and stay (use a hammer or a bench vice if needed).
Then assemble like shown in the pictures. There should be 5 rollers between the numbers.

Body assembly:
Insert bearing into the holder.
Push pin through the bearing like in the pictures.
Push the Big Gear onto the pin.
Insert clock mechanism and secure with lid.
Push the Small Gear onto the minute hand of the clock mechanism.
Insert the assembled holder into the enclosure and secure with M3 screws.
Push one of the Sprockets onto the pin.