The clear acrylic chin forms the lower jaw line of the DARWIN head and holds the rubber sheet that simulates the patient's skin. With regular lab use a chin can crack or wear, and replacing it is a quick job with a screwdriver. The only part that takes any care is the order the washers go on, so follow that step closely.

What you need

The replacement chin comes with its own screw and washers. The lower stopper tray stays on your DARWIN head and is reused.

Lost or damaged your tray? The DARWIN lower stopper tray is sold separately.

Installing the chin

STEP 1

Stack the washers on the screw

Slide the spring lock washer onto the screw first, followed by the flat washer, and finish with the star washer. The star washer ends up against the chin, and the spring lock washer sits under the screw head to keep the assembly from loosening with use.

Order from the screw headSpring lock washer, flat washer, star washer.

STEP 2

Start the screw and slide in the chin

Thread the screw partway into the lower stopper tray, leaving a gap under the washers. Slide the edge of the clear acrylic chin into that gap, so it sits between the star washer and the tray.

STEP 3

Align and tighten

Seat the chin so it is properly aligned with the tray, then fully tighten the screw to secure the assembly.

Next: attach the rubber sheet

With the chin in place, the rubber sheet goes on to simulate the patient's outer skin. Which sheet you can use depends on your chin.

• The chin with connectors takes either the standard rubber sheet or the DARWIN rubber sheet.
• The chin without connectors takes the DARWIN rubber sheet with ear loops only.