In order to familiarise yourself a little with the structure of the instrument, a brief description of the essential elements is given here. A more detailed description of the individual elements is given in the other sections on this page.
In addition to the elements of a piano, there are, roughly speaking, two further components of a pianola according to its arrangement, the upper installation (elements above the keyboard) and the lower installation (elements below the keyboard). The range of functions differs for pianolas, and so does the construction in detail. For a first classification here is a short overview of the construction of a pianola:
1 note sliding block (scale)
2 Wind motor
3 wind chest (contains the bellows)
4 Pedal system (for generating suction air for pedal instruments)
5 Blower system (for generating suction air for reproduction instruments)
6 Emphasis and dynamics control (for reproduction instruments)
7 Electric motor
8 Control levers for controlling tempo, emphasis, dynamics
9 Track control (correct running of the music roll)
Again and again, there are instruments where the pianola components are partially or completely missing. After the heyday of the pianola, many instruments were destroyed or, due to malfunction, removed to be used as normal hand-playing pianos.
The first step was to check whether the complete self-play mechanism was still present. It is not uncommon for only the top installation to be removed in a hurry - or even just the bottom installation. Since it is almost impossible to find a replacement for it and since rebuilding it would be very expensive, we advise against buying such pianolas.