Box #6
Orientation of this box differs from others. The box will rest on its back wall (which will be removed) and the lid then becomes the anterior face of the model. The box needs to have a sliding top which can be fully removed. Our box measured 6 ½” L x 4 ¾” W x 4 ¼” H.1) Remove the back wall from the box.
2) Cut a 1 ⅞” x 1 ⅞” square centered in the bottom of the box.
3) Drill portals in the lid (now the anterior face) and the front wall (now the superior aspect of the model). Both will be covered with the rubber tubing,but this will require filing down the front wall in order for the lid to close with the additional thickness.
4) Articulation: Use 1 ½” diameter pine hand rail with “tibia” portion measuring 17 ¾” and “femur” measuring 4”. Make a cut through the center of a tennis ball and place it on the end of the 4” piece to simulate a condyle. Use finish nails to affix two flaps of bicycle tubing to the end of the longer piece that will articulate with the tennis ball. These mimic a meniscus. Finally, use folded tubing and wide head nails to secure the long end to the short end around the tennis ball. This fixation should be at a relative point of isometry as the model is meant to flex and extend, while not ending up with excess slack, and subsequent sag, while the model hangs in a flexed position.
5) Back anchor: Slide the proximal aspect of the femur portion through the square hole cut into the box in step 2. Cut a right angle from another box with side measuring 6 ¼” L x 5” W. A fully threaded screw with washer should be placed though the short panel into the center of the “femur” hand rail piece. Do not fully tighten as this is the point of rotation for the model.