
In the diagram below are illustrated both common types of button fitted to a button accordion

Type 1 as fitted to all hohners and many other manufacturers
Type 1 has travel limited by either
- A limitation on the mechanism itself back near the soundboard or
- A pad fitted under the lever arm below the button
For B to be possible, either the top or bottom of the keyboard must be removable otherwise it is impossible to get the keyboard over the keys
In the pokerwork it is usual to resort to method A but if you push the buttons too hard they will bend the lever and disappear, don’t push them too hard!
Type 2 a newer style fitted to many new boxes
Type 2 travel is self limiting
The Myth
The Hohner pokerwork style 2 row is pretty much the only box which actually suffers “buttons down the holes” because there are neither a limit on the mechanism or a damper underneath the lever arm to stop the button disappearing down the hole, and by that I mean properly disappearing down the hole and not coming back out, not just stopping at the keyboard level. see picture above
The recounting of this problem has led people to believe that if a button of type 1 is level with the keyboard, that it is “disappearing down the hole” it really isn’t, that is what they are supposed to be like but they can sometimes be set higher if it is desired.
Advantages and disadvantages of each type
Type 1
Button travel can be set so that the crown of the button is close to level with the keyboard top this makes sliding a finger across buttons easier facilitating arguably faster playing
The disadvantage is that they are much harder to set up properly and in the case of a lever limited at the soundboard end, over enthusiastic pressure can bend the lever arm.
Type 2
Idiot proof to set up, the button will always stop at the top of the keyboard top, and it is virtually impossible to bend a lever arm. These are also better suited to stepped keyboards
Disadvantages you cannot slide across the keyboard so easily and keyboard feel is less easily customised
Neither is better just different