Jason Allemann designed and built his very own custom ball clock using only LEGO pieces that has now gone viralviral. The fully mechanical clock picks up one ball per minute, and drops it on the top of three ledges. Balls on the top rail represent one minute each, the second rail represents ten minutes each, and the bottom represents one hour each.
Once a rail is filled, it tips over dumping all but one ball back into the reservoir. The last remaining ball then falls onto the next rail to continue the fully mechanical counting of time.