Feurich High Speed KAMM Upright action

Surely (Shirley 😆 ) it changes the touch weight? Maybe it's insignificant.

spanishbuddha Surely (Shirley 😆 ) it changes the touch weight? Maybe it's insignificant.

Maybe not the touch weight (particularly at the beginning of the key press) because the spring is not being forced, but it should increase a bit the upweight because it seems that the spring is forcing the key return...

According to the KAMM website it doesn't change the touch because the spring is not pressing against the jack while you are pushing the key. It's only when you've thrown the hammer and it rebounded that the spring gets stretched by pressing on the jack (and of course conversely) pushing the hammer forward, not backwards, so that the jack can slide under the butt again.

If you think about that, it's almost the same principle as the double-repetition lever of the grand piano. Very clever. BTW, I think the magnet solution is similar, since the magnets have non-linear force.

I believe all these systems basically do this thing: they prevent the hammer from going backwards (towards rest position) when you start releasing the key and so the jack can slide under it. Whether they use magnets or springs with different shape and location is a matter of patents I guess 🙂

And thinking even more about that, on theory this seems like making the upright action very similar to a grand piano action in terms of repetition capabilities and being able to repeat without releasing it fully. Kamm even states that his device allows for the key to be repeated even when you have released the key only 1mm which is not true for grand pianos where you need to release the keys a few mm more.

CyberGene Very clever. BTW, I think the magnet solution is similar, since the magnets have non-linear force.

Exactly... As far as I (don't) remember, Steingraeber uses attracting magnets but there is another company that uses opposite polarity magnets between the jack and the catcher to facilitate the repositioning of the jack. The problem with magnets is that they need to be small (otherwise the effect is too strong), and small magnets depend a lot on their relative distance. An error in tenths of millimeter causes large differences from key to key. I expect a return spring to be much more forgiving.

Simple and clever. Possibly game changing? If the action was the only limit in an upright, now upright builders have no more excuses, they need to build them as good as any grand, with the same wood, same strings, same cast iron, same everything.

Hello,

Pianissimo need to build them as good as any grand, with the same wood, same strings, same cast iron, same everything.

Happy days, interesting times to come!

Cheers and jolly anticipation,

HZ

vagfilm Do they sell it to anyone or just technicians? Did they quoted a price for the springs?

This is my next step, asking for a price. I will let you know.

Jose

HZPiano Are you still planning of having him "upgrade" your NV5?

Unless Yamaha or Roland release something spellbinding in the next 3 months, then I'll just have to settle for an N1X 😀

Hello,

burkey then I'll just have to settle for an N1X 😀

Poor you! 😎

Cheers and happy anticipation,

HZ

Jose EB5AGV

And? Any luck? 😀

MHirsch Nope, I asked for some pictures on a piano similar to mine (Yamaha U3) and he told me he had not any. Then I got other things to occupy my interest and forgot about that… I am not eager to modify my piano now, I am focused on learning 😃

CyberGene As a matter of fact I believe it’s easy to retrofit them in a NU1X if ordered from Feurich. I would only worry if the sensor system will generate sound if you repeat without releasing fully. From my memory that was not the case. The loud note happened because the sensing system thought you’ve released the keys fully whereas in reality you’ve released them just before that.

For those of us in the United States, it may be fruitful to contact Fandrich and Son's about doing such a retrofit, or those in Canada might contact Oliver Esmonde-White (disciple/dealer of Fandrich). Among other changes, the Fandrich action deletes the normal jack spring (between jack and wippen) and adds a repetition spring between jack and catcher shank, which as far as I can tell does the same thing as the spring/roller that KAMM uses.

Fandrich has been doing the jack modification since the early 90's, and have added/patented other changes in more recent years. Their mission seems to be to make things accessible to people, focusing on moderately priced pianos rather than shooting for prestige and high price/high margin markets, so I imagine they'd be open to supporting people wanting to modify their own pianos.

Modifications to make Fandrich vertical action - YouTube

Pianos by Fandrich & Sons

At the same time, I'm very curious about WNG's take on these ideas.

luns At the same time, I'm very curious about WNG's take on these ideas.

It looks like they're clearly aware of Fandrich's jack modifications. The figures in their patent US20130186252A1 shows holes where the check shank would be (butt, shank and check all being one integrated piece in their design) and more crucially, those holes (40) are labelled as 'Fandrich holes'! What's more, illustrations of the jack in other patents of theirs, also seem to show a corresponding hole in the jack tip. The only thing missing is the spring to go into these holes.

Hmm.. looks like the jack tip hole is there only on their Steinway F jacks and not the others, while
WNG_upright_action_parts_catalog.pdf (wessellnickelandgross.com)

Not sure what to make of this except that they clearly had Fandrich in mind during their design process, but for whatever reason stopped shy of making this a standard feature of their actions.

Nice find...

Also note that this action (like pretty much any single change to the "standard", as far as I've seen through the years) get no love from the majority of technicians: http://forum.pianoworld.com//ubbthreads.php/topics/3187913.html

After reading the comments in that thread, I think they were mostly benign to the action alterations: most said that it works but that it is unstable over time. Not entirely a bashing...

vagfilm most said that it works but that it is unstable over time. Not entirely a bashing...

If it stopped there, maybe. But it continued to the tone of

"and hence it is not worth the hassle/cost of continuous regulation, not to mention of the initial installation"