How to open an upright piano
This article will show you how to open an upright/studio/vertical piano, to give access to the hammer action mechanism, keys and the strings for repair/maintanence purposes.
Although the piano body construction may change from one manufacturer to another, all upright/studio pianos have 3 basic covers that should be removed before attempting any repairs. Check the images below:
In the above picture, No.1 is the top cover which can be kept open during playing, so to increase the sound of the piano by letting the sound escape.
No.2 is the front cover that hides the hammer action mechanism. Most upright pianos will have this part in 2 separate pieces, the upper one covering the mechanism, and the lower one covering the keys.
No.3 is the bottom cover, which protects the pedal mechanisms and also gives access to the lower part of the soundboard.
Opening the top cover (No.1)
The top cover is made to be used open during piano playing to let the sound escape and resonate within the room. There is a small pin either in the middle or on one side, to hold it half open. It opens by pulling it up on a hinged door mechanism.
Removing the front covers (No.2 a&b)
For studio pianos, the upper part of the front cover (No.2a) usually flips backwards for quick access to the hammer action mechanism. In taller upright pianos, this part may not be fixed by screws and might be completely removed. Please notice that, in order to tune the piano, you will need access to the tuning pins, and this part will have to be removed completely before attempting the tuning procedure.
The lower part of the front cover (No.2b) may be fixed with screws or it may lie freely on the keys, serving as a key cover to protect the keys from damage. If it is fixed with screws, use the appropriate screwdriver tip and remove the cover by unwinding the screws in a counterclockwise direction. Once the front cover (No.2 a & b) is removed, you will have complete access to the hammer action mechanism and the strings for repair or tuning. Check the images below.
Removing the bottom cover
The bottom cover is usually held in place by a metal bar in the middle of the piano. Just push it upwards and gently pull the cover towards you. It should have 2-3 pins on the piano that hold the cover aligned to the instrument, be careful not to bend these pins, or force the holes on the bottom side of the cover. These pins act as guides to facilitate reinstalling, when you will want to put it back in place.
Removing a key (for repairing)
To remove a key for repair purposes, you DO NOT need to remove the mechanism. Find the hammer that the key is associated with (simply by pressing the key and noticing which hammer moves), use the tip of your finger to push that hammer slightly up, and remove the key upward and towards you. Please check the article I wrote on repairing broken piano keys, if that is the case:
The following pictures is a brief walkthrough. Notice that the keys rest on balancing (taller) and guiding (shorter) pins. Do not bend these pins in anyway, or the key might be stuck and become non functional. Also make sure that, all the keys are numbered from the left end to the right, this will prevent confusing the places of keys with one another!
How the pedals work
In a contemporary upright piano, there are either 2 or 3 pedals. On the left is the soft pedal and on the right the sustain (damper) pedal. In some pianos, there is a 3rd pedal in the middle, called the practice pedal. This pedal drops a piece of felt between the hammers and strings, thereby reducing the overall sound of the instrument, and it is used to practice otherwise boring mechanical study pieces. In the absence of this practice pedal, one can place thins towels between the hammers and the strings, by opening the top cover and making sure that the towels do not obstruct the mechanism.
Note that although all pianos have pedals, the logic and functioning of the pedals in a grand or baby grand piano are somewhat different.
All these pedals in the upright piano transmit the action through simple upward movement of wooden beams. When the left (soft) pedal is pressed, the beam pushes the entire hammer mechanism forward, reducing the distance of the hammers vis a vis the strings, there by decreasing the sound and smoothing the touch of the keyboard. See the video below:
When the right (sustain) pedal is pressed, it lifts the dampers from the strings, thereby sustaining all played notes. As several notes are played, the sound resonates freely on the entire board and strings, creating an illusion of increasing the volume of the instrument, and facilitates playing notes that are farther away from each other for the fingers to reach. See the video below to see how the mechanism works:
Removing the hammer mechanism
Although a casual piano player will not need to remove the hammer action mechanism, there is no other choice if one needs to do repairs on the mechanism itself, or to change the strings with ease. Removing the covers will suffice to have access to the mechanisms, to examine and troubleshoot possible problems. It is also a good idea to clean the dust from the inside whenever you open the covers.
At this stage, you can examine the hammer action mechanism but in order to change strings or repair the mechanism itself, you need to take out the mechanism as well. Remember that the subtlety of the piano as an instrument depends much on the hammer action, and they are perfected by each manufacturer to insure a smooth and even feeling on the keyboard. As the mechanism presses heavily on the felt cushion in between the mechanism and the keys, a small misalignment may cause problems on the keyboard. Although it should be attempted by a professional, here is how remove the mechanism.
The mechanism is fixed on the iron board with 4 screws. You do not need any special tools to remove this, just turn them counterclockwise with your fingers. You will need to administer some force to pull the mechanism, as it is finely secured to the iron board. Try not to touch the mechanism apart from its iron chassis. The mechanism is very delicate and finely adjusted, therefore you should not use too much force or pressure, as this may bend or break fragile pieces, which may ruin your experience and necessitate to call a professional repairman. After removing, lay the the mechanism on a solid place to rest, preferably on its original orientation, meaning hammers standing vertical as it was in the piano.
Putting it back together
To put the piano back in one piece just follow these steps backwards, and make sure that no screws are left aside :)
Being able to remove the covers of the piano (but NOT the mechanism), will enable to examine the internal structure of the instrument, and will prove valuable when you want to buy a used piano. It also lets the sound resonate freely and move in every direction in a room, thereby augmenting the overall volume of the instrument. Enjoy!