Hammer strike point

Over time, some hammers may become off-center. To center them, the screw of the capstan is loosened and the shank + hammer head are centered. But this cannot be done now, after years of the hammer having "marked" itself on the strings; it would change the timbre because, despite the positive fact that the hammer would strike all three strings uniformly, the non-compacted part of the hammer would end up working. Therefore, I wouldn't do anything. When you replace the hammer rail, we will see.

Another solution is to center the hammers off-axis and listen. Then intervene with voicing to equalize, as much as possible, the differences in sound. (Expert Technician)

Another thing: ensure that all hammers are perpendicular to the strings. If some heads are not parallel to the others, one must intervene with a flame on the shanks to straighten them and correct the inclination of the hammers.

Then verify that all hammers strike the three strings simultaneously (or the two on the bass).

The inclination of the hammers in the starting phase, both vertically and at the tail, can be slightly to the left (bass) or to the right (treble) so that they arrive at the strings truly perpendicular to them. In fact, depending on the drilling angle, as the hammers approach the strings, they describe an arc, more or less evident, a geometric result coming from a mathematical calculation... and not from an optical illusion. All of this affects the final sound result and can compromise and/or distort the voicing intervention.

To successfully intervene regarding these concepts, the technician must be an expert.

Good morning... reading the technician's advice, I wonder if using a grand piano would change the perception of this problem, given the different geometry.

I hope it is not a serious structural defect... sometimes these things cause useless anxiety during practice :)