Week 10

This week I learned about key fitting. When working on keys it is important to take out end play and lateral play in the keys. This extra motion in the keys makes the clarinet feel sloppy to a player and can add extra noise. When fitting a key it is important to know if the key you are working on has a hinge rod with a hallow hinge tube or a solid hinge tube with pivot screws. When working with a hinge tube a rod the key is able to be swedged with a swedging pliers or a swedging collet. Swedging the keys thins the metal which stretches it and makes the key longer. This removes the end play. The lateral play, which is the movement between the hinge rod and tube, can be taken out with the swedging tools because it forms the tube to the rod. This takes up the space between the tube and rod and removes the lateral play. There are two main types of pivot screws: point screws and pilot screws. Standard point pivot screws have a pointed end and a head. These are nice screws to take out end and lateral play. In order to take out play I need to make the screw go in further. This is done by removing material from the post with a pivot screw counter sink.  Headless point pivot screws are the easiest to fix end play because the screw can be placed further in the key tube. Pilot screws are screws that have a cylindrical rod after the threads. There is no fix for lateral play but in order to fix end play washers need to be installed to fill the space.

Swedging collet tool. There are different size collets for
different sized hinge tubes

My clarinet screw board showing the different
hinge rods and pivot screws