I hope someone has a few minutes for a mechanical newbie question.

I think I understand how the action differs on a grand and an upright, so correct me if this is wrong. The hammers on an upright are vertical, and move to and away from the strings vertically, while the hammers on a grand are horizontal and move down and up "over" the strings horizontally. This is a necessary difference since the strings on an upright are vertical, going up from the floor so to speak, and the strings on a grand run horizontal back from the keybed area. Is that a good way to put it?

Ok, so assuming that's correct, here's my question: I seem to remember reading a comment about certain uprights that have hammer action more like a grand. How is that possible if the upright's strings are still standing up vertical? And in what way is the action "grand like?"

Now about pedals, I understand that the left hand pedal on an upright does not involve any keyboard shifting, it creates softness by moving all the hammers closer to the strings (so the hammers move a shorter distance in striking)

On a grand, this pedal (the una corda pedal? is there another name?) causes the keyboard to physically shift (is it the board? bed? hammers only?) so that the hammers strike the strings in a different position, with the result that one less string is struck.

Assuming that is also correct, what happens with an upright that has "grand-like" action? Does the left-hand pedal perform in the same way as a grand, or does it behave like an upright's soft pedal?

Thanks to anyone who can take the time to explain this to me!

good question ShiroKuro for the ones of us with no idea about piano technology. I hope some expert of the forum brings us the light.

ShiroKuro:

For what it's worth (I'm not a piano technician, but I have some experience with them mechanically), a vertical piano does indeed have strings and hammers vertically arrayed, When the key is depressed, the hammer moves forward towards the string, and the damper that sits below the hammer, also in front of the string, is lifted away from the string. The vertical grand action you refer to may be the Fandrich action, but I absolutely do NOT know that for certain.

On a grand piano, the strings and hammers are horizontally arrayed, with the hammers located below the strings, and the dampers above. When the key is depressed, the hammers move up towards the string, and the damper is lifted off (remember, the hammer is below the string, the damper above. The una corda pedal does move the keyframe (holds all the keys) to the right. I don't know of any vertical piano that does that, but again, my experience is limited.

Hope that helps somewhat. There are a number of books out there that go into great detail about the workings of a piano.

Dave

Regarding the pedal question, with the left pedal on a grand (una corda) the entire keyboard and the hammers shift slightly so that the hammers strike one less string than they otherwise would.

The middle pedal on a grand is different from most verticals as well. On a typical grand, the sostenuto pedal will sustain whichever keys happen to be depressed at the time the sostenuto pedal is depressed, but none others. Its useful to sustain a chord while playing other notes that are not sustained. Some high-end verticals have this as well. Other verticals have a middle pedal that sustains only bass notes below a certain point (a cheap way to mimic sostenuto, i guess, on the theory that the chord you might want to sustain is in the bass). Other uprights have a 'practice pedal' in the middle, which lowers a piece of felt between the hammers and the strings, making it much quieter. And of course other uprights have no middle pedal.


I don't know what it means when someone says a verticle has action thats like a grand. Sounds like marketing hype to me...

Lets look at function, as opposed to specific form.

In a typical upright action, as the key is depressed, at some point, the jack trips out and the key finishes the movement via inertia. After hitting the string(s), it is caught by the backcheck. To play that note again, the key needs to be lifted all the way back up, so the jack can "reload".

The major difference in a grand action, is that after being caught by the backcheck, the key only needs to be lifted a little bit, and then the note can play again. This action repeats quicker, with less effort.

There have been different designs over the years to bring this function to the upright action....
So they're not talking about the upright action resembling a grand action, so much as the upright action WORKING more like the grand action.

As to the pedal question; there are many configurations of pedals... I've seen some grands that don't shift, but mimic the upright function of moving the hammers closer to the strings. What is lost is the change of tone that the unacorda brings, by shifting the hammers from hitting the strings on compacted felt vs. uncompacted felt.

Hope this helps.

This helps a lot, thanks RonTuner and jon-nyc and Dapper50. And it's really interesting! Now I'm kicking myself because I had my lesson today (where I play a grand) but I forgot to look inside at the hammers.

So my understanding of the grand hammer movement was wrong, that's good to know.

Given the point about how the hammer moves back in forth in space and all of that, maybe what is meant by a grand-like action in an upright is not the hammer's position in relation to the strings, but how the hammer moves. And yes, jon, maybe it's just marketing hype.

The middle pedal on my piano is just a practice pedal, where a piece of felt drops down in front of the strings, and who wants that! yuck!

I wish I had known about the pedal functions years ago.

When I was a kid our old upright had the pedals described. I could never detect any change in effective dynamics by moving the hammers closer with the left pedal. The center pedal lowered the practice felt but it was so worn out, most commonly used keys weren't softened at all.

Later as an adult I owned a Brambach baby grand. I never knew about the sustenuto deal so I don't know if it worked or not. Also the keybed did move as promised with the left pedal. But again I don't remember detecting any reduction in dynamic. Maybe I was just to ham-fisted or maybe it was just worn out. How does the "una corda" work on you new, well maintained pianos.

Also, does anyone know if these effects are well simulated on the Clavinovas? (probably the best ONE I can hope for).