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I was wondering if anyone here has any experience with this innovation from Feurich to increase the repetition rate on an upright?
https://www.feurich.com/en/innovation/high-speed-kamm-action/

I am wondering if the spiel in german addresses how it affects the weighting and feel at the key.

There is a setting on YouTube to turn subtitles on. Tap the icon that looks like a wheel at the bottom of the video beside where it says YouTube. It is to the right of the play button. It will bring up a menu where you turn subtitles on to English. Hope that helps

This is just another of the various inventions over the years that do the same thing: push the jack under the butt more quickly. I think there are better ones. But the problem is that most pianists do not play in such a way that they can take advantage of it, so it adds cost for little benefit.

This technician has made a few videos explaining it. Here is one



search in the other ones by the same account for more if you care

I dislike the extra spring loading the Fandrich configuration applies. The standard upright action has 2 constant pressure return spring and Fandrich's implementation adds one more. Springs change over time thus making regulation unstable.

Plus the lack of gravity return on the hammer doesn't provide any extra hammer return force to be stored in a repetition spring like the grand does so the whole enterprise of concocting some sort of rep lever in an upright is really doomed.

My configuration of reduced hammer mass so as to allow added catcher mass creates greater positive gravity hammer return than any other upright action available.

I think BDB and Ed McMorrow both make good points. This invention, so-called, is just another implementation of a means of forcing the jack to its rest position; it is not a true double escapement action. The Fandrich action is the only one of these of which I'm aware, which one could consider a double-escapement action.

That was interesting. I hadn’t heard about the fandrich action. I don’t know enough to truly understand the pros and cons of the different systems or how useful they are and to what level of student so thanks for the comments. I am beginning to learn about the mechanics of the instrument I play and finding it instructive.

There have been many different upright action designs that improve the repetition rate. The earliest I have worked with was a Mason & Hamlin upright from the 19-teens that had small leaf springs on the hacks that pushed against a felt pad on the back of the catchers. It gives excellent repetition, like a grand piano but with a different feel than a grand.

Each design I have seen has drawbacks, some minor and some major. But the real reason they aren't adopted more widely is because of the cost. Uprights tend to be the more economical alternative, and so running the price up by making a special action does not usually sell well.

I once restored a Mason & Hamlin upright with the WN&G repetition action, and it had a lot of features which I did not appreciate at the time, but looking back on it, if I were to make a repetition action, I would adapt it.

The features that I liked were that the leaf spring pushed against the backcheck, which works somewhat like a grand repetition lever to hold the hammer at an intermediate point and make the repetition faster. I liked the fact that the spring tension was adjustable with a screw.

The drawback was the difficulty of making the leaf spring, which fatigued. I have never seen one of these actions where the leaf spring had not collapsed.

I am not certain about whether it is possible to make a spring which will not fatigue, but it is definitely possible to make a spring that would be cheaper to manufacture, simply by bending one from wire. It would need the two eyelets for the escutcheon pin (a screw would work) and the adjusting spring, and it would need to be shaped to push against the backcheck freely.

I have said before that I do not like butt springs with loops. I do not feel that they give steady pressure agains the hammer butt. Spring (damper stop) rails are better, but difficult to make. As I have said before, running a spring from the butt to the damper stop rail is no more difficult than the spring to the loop, so I would add that. But I am getting older, and I do not have any financial incentive to do anything like that, but I may try the spring the damper stop rail sometime if I come across an action that needs the loops replaced to experiment on.

One way round this problem is to regulate your upright to repeat. I did.

Bill Breemer explained how to do it in this post.

My option of reducing hammer mass to allow adding mass at the catcher usually allows one to eliminate the hammer return spring. Everybody else tries to add a third spring. I prefer simpler physics.

Springs weaken with age and smaller springs weaken faster. The Fandrich action is difficult to regulate and goes out of regulation easily with relatively small changes to the springs.

With the cheap availability of carbon fiber hammer shanks which can be smaller in diameter than wood ones makes reducing hammer mass easy by simply making the hammers narrower to begin with. Uprights can also have the unison strings spaced closer together to allow for narrower hammers.

I don't think factories should find my design difficult to execute.

Ed,

Can you post a photo showing how much material you remove generally speaking on an upright? I made myself a little "taper gauge" to help me uniformly taper them. I have noticed a definite difference between the tapered and non tapered hammers leading me down your road.

Peter Grey Piano Doctor

What was the difference?

Oliver Esmonde White, who worked with Fandrich, now builds pianos in Montreal using an improved version of the Fandrich action that now has a screw to facilitate regulation. I have not seen it in action (no pun intended). Most of the site is in french and no pictures....

https://www.pianoew.com/en/piano-magic

If you search for esmonde white piano action on youtube, there are quite a few videos. Here's one.

I don't have numbers to post. Much of my work is testing samples to determine the parameters and then using tools such as calipers to keep the derived dimensions uniform.

I have only done four High Performing verticals. I am doing a 5th right now. Each one is unique to the piano I am applying it to.

I could feel it immediately, as well as a tonal change (subtle but there). I have also been hampered by less than ideal checking on verticals with new hammers. They are clearly heavier than the originals. I plan to continue the tapering all the way through the action rather than just the top 30 notes (which I had Ray Negron do for me).

Peter Grey Piano Doctor

As you know I am inexperienced and avocational, but based on my understanding of this configuration, they do add one spring (at the tip of the jack) and remove one (at the bottom of the jack), so the total count remains unchanged.

I will admit I didn't follow all the agonizing evolution of what is called a Fandrich vertical action. The first ones had three constantly loaded springs.

In my experience, when freshly regulated, they do play smoothly, but that regulation doesn't hold up well with use.