Why does the hammer of the upright piano swing hard during movement?

[themaximillyan]

Why does the hammer of the upright piano swing hard during movement? How can it be fixed DIY?

In the provided video, it is evident that 'the hammer of the upright piano' is excessively loose, causing it to swing from side to side when the piano key is pressed. This technical issue is unacceptable as it hinders the pianist from fully expressing their musical abilities. While there could be various reasons for this behavior, it is likely due to a simple loosening of 'the hammer flange screw'.

To address this, use a standard screwdriver. With your left hand, hold the shank or head of the hammer, and with your right hand, insert the screwdriver into the groove of 'the hammer's flange screw' and tighten it clockwise. If the hammer now strikes the strings evenly without swinging, the issue should be resolved. However, there are instances where this fix may not be sufficient.

Here are additional tips on how to rectify this issue:

1 If you observe that 'the pin' has shifted slightly to the left of 'the hammer butt flange', attempt to realign it using a screwdriver. Gently push on the pin's end to correct its position without removing the hammer from the upright piano's action.
2 If realignment with a screwdriver is unsuccessful, remove the hammer from the upright piano's action by unscrewing it from its mounting point. Use pliers to carefully adjust the pin back into position, ensuring not to overtighten or damage the pin or hammer.
3 Excessive swinging of the hammer into the hammer butt flange may indicate worn-out or damaged cloth bushes of 'the hammer flange'. In such cases, replacing the pin with a larger diameter one should enhance fit and stability.
3 If the hammer remains loose despite previous attempts, remove 'the action' from the upright piano and, using a screwdriver, tighten 'the screw' on the opposite side of the loose hammer in a clockwise direction. This 'the hammer butt screw' is typically found in a metal plate and can help reduce the hammer's looseness

4 If the aforementioned methods do not resolve the issue, it is recommended to seek assistance from a professional piano tuner or technician. They possess the necessary expertise and tools to replace the old 'the hammer butt flange' or install new cloth bushes as needed to restore the hammer's functionality and stability.