This wooden clock is an MLT-13 design, first published in the Spring 2007 issue of Scroll Saw magazine. The plans have been available in other magazines and reprints from the publisher and you can also find them around the web. This is an interesting design that includes hour, minute, and seconds hands. Although it was originally designed to be cut out using a scroll saw, I redrew the parts in CAD and made most of the parts on my CNC machine. Even so, there was a lot of sanding and fitting needed to get the gears to work smoothly. The clock is entirely driven by the weight and it runs for about a day before the weight needs to be pulled back up. By adjusting the bob position (i.e. the length of the pendulum) pretty good accuracy can be achieved – on the order of 10 to 20 seconds error per day. As would be expected because it’s mostly made from wood, it’s difficult to keep it running as the temperatures and humidity changes.
CNC machine is a great tool to cut this out.