Tuesday, December 11, 2012

Key Leveling

We recently wrote a post about tone hole leveling, so we thought it would be a good idea to talk about another leveling process -- key leveling.  This is something that is done by our finishers immediately after the pads are put in the keys.  However, at this point, the pads are put in just to get a general overview of how the mechanism is functioning.  The pads are shimmed later in the process, after the key leveling.  Flute finishers need to make sure everything is level before the final pad shimming.

So, once the pads are put in the keys, the finisher closes the key and checks all the way around with a feeler gauge (same gauge used to check for leaks).  This process allows the finisher to see where the key might be "heavy" or otherwise unlevel.  If the key is heavy in a spot, it would need to be pushed up.  The finisher takes a piece of felt and puts it under the key to protect the metal.  Our finisher Karl Kornfeld mentioned that other materials could be used instead of felt -- leather, cardboard, paper -- essentially, anything softer than the pad.  A spring loaded tool called an "automatic punch" is then used to apply pressure to the key to level it.  This tool can be adjusted as well.  After the keys are leveled, the finisher lets the flute sit for at least an hour because metal "has a memory" and can shift back to it's previous shape.  Once all the keys are leveled, the finisher can then begin shimming the pads -- into nicely adjusted, level keys!

Using feeler gauge to check for spots that aren't level.
"Automatic Punch" is the tool used to apply pressure.
Prepping by placing felt under the key.

Applying pressure with automatic punch tool.
Tip of this tool also has felt to protect the metal keys.

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