|Flute keys (Yamaha concert flute) (Photo credit: Wikipedia)|
One of the weakest points on the flute is where the foot joint joins the body. This is called the lower tenon and can be easily damaged. The foot joint can become loose and cause air leakage and loss of sound or become too tight and be very difficult to remove or put on. This can lead to numerous problems. The fact is that the foot joint is long, almost 6 inches in some cases, and the tenon that supports its weight is only half an inch long. Supporting that much weight and length as well as being constantly put under the pressure of the keys being pushed down can tend to take it's toll if not maintained.
Like the body of the flute, the foot joint keys, springs and pads have to be maintained. Replacing, levelling, and seating all have to be done in order to have the keys seal correctly and thus allow the lower notes to play.
Almost all of the keys of the flute work in conjunction with one or more other keys. This means that when you press down on one key it may also cause one or more other keys to be pressed down at the same time. These keys have to be regulated so that when it is required that two or more keys close at the same time, it has to be the same time or you will have loss of sound and the flute won't play. Regulating the keys so that they work in this fashion is probably the most vital repair of the instrument. It requires a delicate balance of bending and levelling the keys as well as seating the pads better and adjusting spring tensions.
The final result of all of this should be a flute that is solid feeling, with no rattles or excessive key noise. No sticky pads or loose feeling keys. When you press the keys it should be very light pressure with a big sound and minimal effort. The last thing you want when you are playing the flute or any instrument really is to be fighting with the physicalness of it instead of just enjoying the artistic and creative nature of it.
To sum it up, you need to have respect for the instrument you are playing and give it the attention it needs. Care and maintenance mean that it will always perform the way it is intended to play and you will enjoy your creativity uninterrupted by physical glitches.