Vertical Ball Clock

7,50  -Excl. Tax

A combination between a clock and a marble run, as a LEGO Technic Vertical Ball Clock, with hours and minutes digits represented by balls in vertical digits, powered by a single motor. 


Video Presentation



  • Ball Clock inspired by Horizontal Marble clock from Idle-Tyme
  • Three variable length vertical digits (one for the hours from 1 to 11 / one for the tenth of minute from 1 to 5 / one for the minute from 1 to 9)
  • Ball reservoir on the bottom (39 needed balls) with motorized agitator
  • M Motor powered the lift which makes one revolution each 60 seconds
  • Each times a digit is full, it is reset to 0 and the extra ball go to the next digit with special mechanism
  • When all the digit is full (11:59), all the digits are reset (00:00)
  • Digit reset is made with a mechanism which triggers the digit trap only when a ball is in the mecanism
  • Ball pump is used to lift the balls which need it, from the minute digit to the hour’s
  • Period of the lifter (60s) can be adjusted by removing or adding a chain link (shock absorbers stretch the whole chain to keep it straight)
  • Resolution of adjustable chain link is 0.5s (one chain link over a total of 114 chain links)
  • Accuracy is not very good, around 1-2 minutes each hours, worst than a quartz clock of course, but ball clock is cool, isn’t it ?

For detailed explanation of all mechanisms, please watch the video above or read the full review of this model on the blogpost.


How to build ?

You can purchase the PDF instructions on this shop and build it with your LEGO parts. The instruction contains the partlist at the end, but you can check individually on Rebrickable, or in the instructions previews below.

Please note that the yellow frame on the original picture has been swapped to black one, to use more common and affordable parts, which doesn’t change at all the functioning.


About this product

Instructions preview


Additional information

Model Size



Black, Yellow


All, Machine


Yes (machine)

Building Difficulty


Piece Count


Bill Of Material

Purchased File

PDF Instructions (About 246 pages / 98mo)