The other day I was talking with a friend who is in the process of building a blanket chest for his new granddaughter. He’s planning to use a gas strut-type of lid stay and asked if I had any bright ideas about how to locate the mounting points so the strut would allow the lid to open and close correctly. I had just been modeling the steam engine, shown below, and had a number of occasions to do something similar while connecting the various linkages. The key to the process lies in using a brilliant plugin called Tangent Tools to find the real intersections of a couple of arcs or circles. In the video I will show you what I showed to me friend and then I’ll show you how I connected the linkage between the centrifugal governor and the steam inlet valve on my steam engine model. I expect you can find a number of other applications for this in the design of various jigs, fixtures, and other projects in your shop.

-Dave