Configuring the Jaw

 by Al Stevens
al@alstevens.com

The head kit includes brass rod and tube axle hardware. Configuring the jaw ought to consist only of installing that hardware, but there's more to it.

Installing the Jaw Axle Tube

The kit has a long brass tube, two short brass tubes, and a brass rod. We're interested only in the long brass tube in this procedure. We'll use the others when we install the jaw into the head in the section titled Installing Mechanics.

The sides of the jaw are already drilled with holes for the tube.

  1. Insert the long brass tube into one side hole and push it through into the other side hole.
  2. Seat the tube flush with both holes.
  3. Permanently bond the tube ends on the inside of the jaw with Apoxie Sculpt.


Notching the Jaw

The shape of the inner jaw gets in the way of some control mechanisms given how we have decided to configure the headstick. Specifically, the eye movement control rod will be mounted on the front of the headstick as described in The Headstick. The control rod will come up vertically from the front of the headstick, past the jaw, and into the eye movement assembly. The top and bottom parts of the back of the jaw are in the way. You must cut away part of the jaw to make room for the control rod.
  1. Before you start hacking away at the jaw, put it inside the head with the mouth closed. Mark with a pencil where the bottom of the jaw meets the neck. You don't want the notch to come beyond this point. Otherwise Fred will look like he has a permanent tracheotomy.
  2. Use an Xacto knife to carve notches in the jaw to make room for the control rod.

String and Spring Screw Eyes

 The jaw is configured for the jaw movement string to be in the center of the jaw. There is a tab at the jaw bottom on the right where you are supposed to put a screw eye for connecting the mouth string. Our configuration puts the string to the left. The notching procedure just described obliterates that tab. You'll have to replace it in the proper position for a left jaw control.
  1. Build up a new tab with Apoxie Sculpt.
  2. Insert a screw eye into the jaw at the bottom left for the mouth control string.
  3. Put a screw eye into the tab at the upper left of the jaw for the spring that holds the mouth closed.
  4. Reinforce this screw eye with Apoxie Sculpt.