A good view of the working end of the drawknob mechanisms. In modern instruments like this one, the movement of the slides is done with the gray, rectangular electric solenoids. These are controlled by the drawknob switches which the organist controls either directly, or using combination pistons. The solenoid motion is translated by small levers and transmitted along the round aluminum tubes into other parts of the instrument.While modern instruments are still built with mostly traditional materials, the wind chest sliders are one place where modern materials have proved better. Here, sheets of gray plastic (PVC) are prepared for installation. If the JPEG image is good enough, you can see the regularly spaced holes drilled in the plastic. The sliders move back and forth to control whether wind goes into particular ranks of pipes.Here we can see some of the slider control arms amongst the metal pipes.
