The principle is the same as the one my Mother used to make a heavier piece of string by twisting a single strand tightly and then doubling it back over itself. The string would immediately twist itself into a double strength strand. A guy brings a machine to Heritage Days every year and it uses chains and sprockets on the three hooks instead of proper gearing. Works the same though as it twists the strands which you slide through a three holed piece of wood and allow to twist together. Jesse > As, ideed, would I. Did have a sketch of one somewhere once & I think I > understand the principal but ... > MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.