Although apparently all the machine heads seem to be the same, their quality is very important, particularly for the precision and durability.
In the past, the machine heads were made of wood. In fact, nowadays this kind of machine heads is still preserved in some flamenco guitars, although most are the mechanical ones, which are the most common we observe today.
In the Spanish guitars, this element consists of two pieces, each one with three mechanisms, if it is a six string guitar.
In the case of acoustic guitars, each string has a mechanism which is independent of the rest of them, since they are not grouped, they are individual.
The machine head is a very important piece, because it will help tune the guitar in an easier way; so that you must install mechanisms with a minimum quality.
In the case of the luthier guitars, it is necessary to take into account that we can find some handmade systems and with high prices. In fact, there are some systems which cost around one thousand euros.
In addition, aesthetics is also important, but above all their quality.
The right quality is essential to guarantee the durability of the different elements. Otherwise, the only option could be to replace them.
When the machine head or its components are replaced.
A priori, the machine head and its components could seem the same ones, but it is not true. If we try to change it completely, it is important to check its characteristics.
It is very important is to check that the screws are in the same place as the original one, just like the tubes where the strings are rolled.
Replacing the machine head
On the other hand, if you want to replace some components, there are also some features to take into account.
Regarding the machine heads to tune, if a string is broken or if you want to install other strings with different colours, there are several hole sizes.
The hole of the machine head must be adjusted to provide the correct resistance and to be able to move the tuning mechanism.
There are machine heads with holes of 3.5*4.3 mm, 3.8*4 mm or 3.2*4 mm. Moreover, in the case of the acoustic guitar, it can also be found of 3*4 mm.
It is important to be sure about the dimensions in order to buy the right pieces.
Replacing the gears
It is possible that in the gears, a cog breaks. In this situation, the only is to replace the piece.
To do so, it is important to know that the internal shape of the gears varies. We can find some shapes such as hexagonal, square or even oval shapes.
It goes without saying that if the shape were round, you would not get enough resistance to move the mechanism.
If the appropriate gear is not found, the solution could be to change the tubes where the strings are rolled.
In the part of the tubes is where you can find the part which fits in the gears, so you should buy compatible tubes and gears.