Chebyshev Linkage II

This linkage is a variation on Chebyshev linkage. Unlike many of the other linkages, this linkage allows you to rotate a piece through a full rotation. The hole in the top of the long bar travels in nearly a straight line for part of its path.

Steps

1. Cut out the pieces from card stock from the pattern. You can use an old manila folder if you don't have card stock. The short dotted lines at the top and bottom of the page can help you line up the cuts on a paper cutter.
   
2. Punch the holes where marked. You may have to cut out a hole with a knife if your hole-punch doesn't reach.
   
3. Cut along the lines of the tabs.
   
4. Lift the tabs marked A on the fat piece (which will be the handle in the model). Slip the tabs through the holes marked A in the long piece and then through the hole marked A in the shortest piece. Flatten the tabs.
   
5. Lift the tabs marked B on the short piece and push them through the hole marked B on the rectangle. Note that the tabs will protrude through to the underside of the model. The rectangle will be on the bottom, the short piece will be next followed by the long piece and then the handle.
   
6. Attach the middle-sized piece as shown in the diagram.
   
7. Turn the crank and watch the hole in the top of the long piece come close to travelling in a straight line.