This project is a vertically aligned scotch yoke mechanism. Turn the handle on the box and the vertical shaft moves straight up and down. Use this model to learn about how mechanisms or as a starting point for your own paper animation characters.

Turn the handle and the rotating pin in the yoke drives the vertical shaft straight up and down.

Print out the parts onto thin card 230micron / 67lb. Coloured card makes for a colourful model!

Score along all the dotted and dashed lines and cut out the holes. Carefully cut out the parts.

Glue the vertical shaft and shaft alignment piece to the marked area on the yoke.

Fold in the sides of the yoke to make right angled triangle tubes. Note that these are valley folds.

Fold the yoke round and glue it together.

Fold up the yoke end piece to make a double triangle then glue it to the backing piece. Repeat this process with the other yoke end.

Fit the yoke ends onto the yoke making sure that everything stays nice and square.

Fold up the two slide tubes.

Glue the slide tubes into the inside box side lining them up snuggly with the corner and edges marked.

Fit the slider tube into the lid.

Glue the box stiffeners across the underside of the box lid.

Glue the box lid to the box sides as shown above.

Fit the box back inner into place lining the edges up with the crease lines in the box back.

Assemble the pin holder parts as shown.

Roll up and glue down the pin. Fit the pin into the pin holder.

Assemble the handle. Fold round and glue up the three tubes.

Fold the three sections into each other.

Complete the handle by rolling round the long tab and gluing it down.

Fit the drive axle into the box back assembly.

Glue the handle onto the shaft.

Glue the drive pin to the other end of the drive shaft.

Glue the back to the handle and fit the vertical shaft up through the slider tube.

Assemble the box. As you do so, make sure that the drive pin is in the yoke and make sure that each of the double triangles on each end of the yoke are straddling the one of the vertical slide on the inside of the box.

Fold the front tabs in and glue them down.

Make sure all the flaps are glued down.

And there it is! Turn the handle and the vertical shaft moves up and down.

Time to add your own character to the top of the box