Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Lowering the strike-point on an upright?

I have a cheaply-built upright in which the upper treble hammers strike very close to a ridge on the harp, over which the strings run before they reach the tuning pins.

Is there a way to lower the strike-point? I've tried sliding the action towards me a bit, so that the hammer falls farther along its arch, but this either does not make enough of a difference in the strike point or pulls the hammers so far away that they do not reach the strings.

I could remove the hammer shafts and reduce their length, of course, but my hope is that there may be some less drastic method. Any suggestions?

Even in very expensive uprights, "the upper treble hammers strike very close to a ridge on the harp, over which the strings run before they reach the tuning pins." Striking distance of 1 mm to 2 mm below the V-bar is normal. Due to the bulging shape of the hammer, it can sometimes look like the hammer is actually striking on the V-bar.

If absolutely required, the strike line can be adjusted, but it is involved and will require some regulation. It should not be done by a layperson without a context of knowledge and experience.

If you have concerns regarding the hammer strike line in your piano, ask your tuner about it the next time you have your piano serviced.

Thanks. On hard strikes in the upper octave and a half, the hammer does hit the V-bar, making a distinct thonking sound. (It is flattering to call this a V-bar, for this piano does not actually have a separate bar or capo--the harp itself is molded so that a ridge rises up to press against the string.)

But thank-you. I will see if my tuner can adjust these hammer heights without getting into a full regulation.

It might be easy to do, or it might be difficult, depending on how the action is mounted in the piano.

If you are going to DIY it,it might be better not to waste your time on a cheap piano?
Here, in the UK, very well made old pianos are available for next to nothing.
On my 1945 big upright I was able to adjust the strike line by moving two large (15mm dia) bolts which support the HerbergBrooks action. I then had to make further adjustments but it was a "piece of cake" and made a BIG difference.
Another alternative, if you find it necessary to use those high notes, is a keyboard - problem(s) soloved.

You could file down the upper edge of the hammers towards the striking surface slightly effectively lowering the striking point of the hammer, but this might not help or could even make it worse. The striking point is very critical at the top and you will get a wooden "thunk" if it is too low as well as if it is too high. Looks can be deceiving here.

My tech tells me the best pianos have very light hammers at the extreme top so they bounce of the strings more rapidly for more "ring" and less "thunk."

Cheap piano -- don't expect a whole lot out of the highest octave.

There are usually four vertical lag type bolts with round tops that the action brackets rest on. Take the action out and tighten all the bracket screws. Lower the middle two support bolts about a quarter inch or so so that the action is only supported by the two ends ones. Put the action back.

Carefully lower the bolt under the treble bracket until you are happy with the sound. You should only lower treble end of the action by about a sixteenth of an inch, sometimes slightly more or less. Keep track of the bolt's original position. Try the rest of the notes above the break, and make sure all the dampers are still working well. Take the action back out.

I use a straight edge to raise the two middle bolts back up into position. Action back in. Hope this helps. You may want to hire a professional, because there might be much more to it than the simplistic fix I've just outlined.

some actions can bend, front to back and up /down.

but the dampers may need to be repositionned.

For small corrections the shanks can be bend a little.

prior to any of those operations the hammer shape must be perfect with the crown well located at the apex whenever possible.

You could check for percentages of the string lenght, as 1/10 for A5 1/11,5 for a6
depending of the progression of the octaves there are also standard strike points. as 2.8mm for A7 4mm for F7, 5.7 for c#7 ... 19.5 for a5.

old hammers being shorter they will tend to strike too low, not the opposite, if this is the case.

As most vertical hammers are bored with a slight downward angle from the shank, as the felt wears down, the hammer will strike higher, not lower.

yes, I stand corrected on that point

Thank-you all for the possible solutions. I'll see what can be done this weekend. I do not have great hopes for this piano, but I like the sound in the tenor and midrange. Thunky in the bass, which is no surprise, but it occurs to me that lowering the action overall might be worth a try for that area as well.

One thing that surprises me is that several people have mentioned that a space of a very few millimeters between the strike-point and the V-bar\ridge is usual on an upright. Why? If the standard practice in the bass and midrange is to set the strike point so that it corresponds with, or avoids damping, one of the nodes, why is this practice abandoned in the upper treble? The V-bar\capo\ridge could be shaped to slope upwards, so that the strike point would be lower without having to move the turning pins higher.

Because of the length of the strings the strike point of the bass strings has to be moved a lot to make a difference. More than likely, the bass is dead for reasons other than strike point.

Strikes are from 1/10 to 1/20, or more in the treble, (up to 1/32 I was told) for better energy transmission and to avoid/lower wooden noise of the impact.

The strike line for basses and mediums depend of the size of the piano and the level of tension/stretch of the strings. Small pianos that have hard strings can sound good with 1/7 in basses. On a piano with low tension the strike must be with a higher ratio . If not the string absorb the hammer stroke too easily.