Iron Ring Clock

The Iron Ring Clock is a clock of unusual design created by four Mechanical Engineering students at McMaster University in Hamilton, Ontario, Canada. The clock was designed and built as a thesis project by Patrick Burton, Braden Kurczak, Michael Paddags, and Peter Whitred. It won the 2nd prize for Manufacturing at the 2003 Canadian Society for Mechanical Engineering Student Design Competition. The clock was simultaneously put into commission and donated to McMaster University in September 2003. The term iron ring as used here refers to a ceremonial ring worn by many Canadian engineers, and does not specifically refer to a ring made of iron.

The clock was designed in large part in a four month period at the end of 2002, with some features which were originally intended for an outdoor installation. The clock keeps time through the use of a synchronous alternating current motor, which regulates its speed based on the frequency of the electricity that it is fed. The top and bottom halves of the ring can rotate independently, with the top half of the ring displaying the hours, and the bottom half the minutes. The minute ring moves constantly, while the hour ring increments once an hour through the use of a Geneva drive mechanism. (The mechanism used in the clock differs slightly from the one shown in the graphic as it has only 4 spokes.) The rings are driven through a gearbox which was designed and partly manufactured by the group. The two ring sections are made of forged stainless steel, with machined surfaces, and facets cut using a robotic six-axis water jet cutter. The central shield, which is the university coat of arms, is made of hand-crafted stained glass. The design of the clock was completed entirely with computer-aided design software, and CNC tools were used for components where the most precision was required. Although the clock was donated to McMaster University on completion, it is maintained by members of the team that built it.

To minimise costs, the team with help from technicians manufactured as many components as possible in an on-campus machine shop. The total cost of the clock was approximately $20,000 CAD, which was raised through donations, with donors listed on a nearby plaque.

The team believes that the iron ring made for the project, with a diameter slightly greater than 1 metre, is the largest in the world.