Peaucellier Linkage II

 Peaucellier linkage

Here is another version of the Peaucellier Linkage that transforms a rotational movement into straight line movement.


  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 using a knife.
  4. Connect the two shorter pieces to the rectangle at the point marked "A" on the rectangle. To do this, lift up the two tabs perpendicular to the piece and curl the ends in so that the pieces with the holes can slip over them. Flatten the tabs again, thus holding the pieces in place.
  5. Connect the shortest piece to the hole marked B in the rectangle. Note that the tabs will go down to the underside of the model.
  6. Connect the rest of the pieces as marked.
  7. Hold the rectangular piece flat on the table (or tape it down) and rotate the arm at point E and notice that the point D travels in a straight line.


  • James Watt, of the steam engine fame, created a linkage in 1784 that comes close to creating a straight line. However, it was only an approximation. This linkage discovered by Peaucellier in 1864 is exact.