Recently I was tasked with building a 7′ wall clock at a property management company and here’s how I did it. I’ve never built a clock before, so there was a fair amount of research to determine what clock motor to purchase that could run such long hands. Eventually I settled on a C1MI-G1 from Electric Time Company.
A drawing of the clock to be made The dial markers are made from aluminum tubing with the ends capped off.
The first step was to cut a square hole in the brick wall and install the motor housing. It is held in place with masonry screws and two cans of expanding foam. It’s important that it is aligned with the face of the wall so the motor shaft will be perpendicular.
Next I laid out the locations for the dial segments with painters tape. The segments have 3/8″ bars welded to the backside which get epoxied into holes drilled in the brick.
The hole locations are critical, so I built a layout tool to mark the holes. The tool slips over the motor shaft and I used a digital level to find 0º, 30º, and 60º,
After the holes were drilled I epoxied the dial segment pieces in place. I used the digital level again to make sure they are tipped at the right angle.
The hands are made from 1/8″ aluminum. I TIG welded an aluminum “box” at the end to hold enough lead to balance them. The minute hand needed 8 pounds and the hour hand 5 pounds.
The counterweights were so thick that there was less than 1/4″ clearance once they were mounted on the motor shafts
The dial segments epoxied into the hole in the brick.
The final product!