Installing the Jaw

The other day I cut out the jaw from the cast face. Now it's time to turn it into an opening and closing jaw. First, I must build what Winch calls in his book on ventriloquism, the "casket," which is simply an internal structure that provides a palate to support his tongue and an axle on which the jaw pivots.



The casket's axle has to be positioned at the center of an imaginary circle of which the arcs defined by the horizontal slots when viewed from the side are a part. Got that? If it's confusing, here's an article titled Building a Precision Mouth Movement that should explain it.

After you've done it a few times, you can position the axle by eye.

With the jaw and its axle assembled, I put the jaw back in the face flush with the cheeks in its normally-closed position. Then, with MagicSculp, I build two small shelves on either side of the inside of the face. The shelves have depressions into which the axle lowers so I can insert and remove the jaw while I tune up its movement. Later, when the jaw is working smoothly and precisely, I'll install the jaw permanently.