Gauging the Situation

Checking pads with feeler gauge.

We've seen our flute finishers checking pads with a feeler gauge, but we recently stopped by to see finisher Lindsey McChord, and she was in the process of making a new one.  Why?  How?  Well, we will answer those questions in this post.

Lindsey explained that the feeler gauges actually do wear out -- and rather quickly.  That may seem surprising, but it is because they get a LOT of use here at Powell.  They are used in flute finishing, repair, and even testing.  The gauge is a small piece of mylar attached to a very small stick.  Lindsey says that she can tell when it needs to be replaced because there will be "wear" at the tip.  Also, when the gauge becomes worn, it tends to snag when being used.  Lindsey uses about 2 gauges per flute -- one for the body, and one for the footjoint.  She says that the number can vary depending on the situation.  Also, if the finisher is working on a flute that is almost done, using a new gauge is not a good idea, because it can leave a black line on the pads.

Making a new gauge involves a few steps.  First, finishers will cut a large piece of mylar, which will be used to make several gauges.  It's convenient to keep this large sheet at their bench.  Then, a very small strip is cut from the large piece.  It's important to cut in a very straight line so that there are no bumps or snags in the material.  Cutting the correct width is important and takes practice.  If the piece is too wide, you will not be able to feel leaks as easily.  If the piece is too thin, you may pick up small things that may seem like problems, when in actuality, the pad seating is correct.  The small strip is then curled vertically just a bit to thread it through the cap.  It's good to have it extend just a bit past the bottom of the cap because it will get pushed forward as the stick is inserted.  Once the cap is secured onto the stick, you are done!  The gauge is a simple tool yet extremely important in detecting leaks and seating issues with pads.  It is also not too difficult to make new ones, although as is the case with flute finishing, practice makes perfect!

Cutting a strip from the large piece of mylar.

A straight cut is important to avoid bumps or snags.

Width must be accurate.  Here, Lindsey explains the issues with a piece that is too wide.

Getting ready to put the new strip on!

Curling the strip to thread it through the cap.

Strip in cap.

A bit of the strip should extend past the cap -- it gets pushed as stick is inserted.

Done!

The Bionic Flute Finger

By Steven Wasser

Innovations sometimes come like a lightning bolt from the sky, but more often are the result of a sustained, disciplined approach to testing ideas.  At Powell we know that each flutist blows differently and touches the flute keys with differing pressures.  In order to control variables like these we develop tools and techniques that come to close to replicating the “typical” flutist, but also allow us to accommodate other playing styles.

Powell is currently investigating the quality of the seal between pads and tone holes.  In order to conduct the necessary tests we developed a simple “bionic finger” that close a key with pressure that is equivalent to finger pressure and also comes from the same angle as a flutist’s finger.  The device uses a series of weights on a shaft which approach the flute key from a tangent position.  We add weights until the key closes securely then we total the amount of weight required.   

The bionic finger device does not result in an innovation, but allows us to test other ideas that could well improve the quality of the flute.  Stay tuned…

The "bionic finger" aims to replicate human finger pressure and position.

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.

Flute Finisher - Part 1

Building flutes requires much time, dedication, and materials.  There are many steps involved in the process and much hand craftsmanship.  If you've heard the term "flute finisher," you may wonder what that person's role is in the process.  It seems logical, based on the title, that this person would be the last person that touches the flute before it goes to the customer.  But, alas, there is much that the flute finisher must do first...

Flute finishers receive a "flute kit" that has all the parts necessary to finish a flute.  The flute kit consists of the body, keywork, and steels.  The parts of the kit have already gone through several steps from raw materials to finished parts.  In the flute kit, the body has tone holes -- whether they have been drawn or soldered.  Ribs and posts have been soldered to the body as well.  The keys have been formed and are attached to the mechanism tubing.  The steels are finished and shaped to fit into the mechanism tubing.  When it arrives at the flute finisher's bench, the parts of the flute in the kit are covered with protective blue film to prevent scratches while the finisher completes his/her work.  With Powell Signature and Conservatory flutes, the bodies and keys have already been polished.  With Powell Custom flutes, the body and keys will be polished by the flute finisher.

The flute kit has many essential elements, yet there are a few that the finisher will add as well.  Finishers add springs, hand-shaped corks, and felts.  They pad the keys, adding shims as necessary so that the pads are seated correctly.  Finishers also have to make sure that the keys are fit properly to the body.  In our next post, we'll take a look at the exact series of steps a finisher goes through -- beginning with the flute kit and ending with a completed flute ready for shipment!

Aurumite Conservatory "Flute Kit"

Flute kit contains body, keys, steels.

Bodies have tone holes, posts, ribs. 

Another view of the flute kit.

Close-up on keys and steels.

Close-up on more keys and foot joint.