Repetition mechanism for upright pianos

CrisOliveira · 2026-01-09T20:49:53+00:00

Or "Why are most makers not trying to develop repetition mechanisms for all upright models?" Grand pianos have a repetition mechanism that resets the jack before the key is fully released. Such mechanism isn't present in upright pianos. Some makers and technicians, however, have offered alternatives. One Japanese vendor installed magnets that repel the hammers back to resting position, so repetition can happen sooner. I can't say how good or fast that mechanism is, since all information I have is from a single tv interview (which I can't seem to find on YT now). Seiler Pianos seem to offer another magnet-based system, with hammer and jack repelling each other. Piano Buyer states some top tier European models also include similar feature. Feurich has their KAMM action, which adds a little felt pulley, attached to the hammer by a spring, that forces the jack back into place. This Russian dude has invented an action featuring what looks like a repetition lever, but I can't understand Russian. Too bad war and politics will stop major brands and him from making deals. Unless he moves out of the country, I guess. Some players and vendors state Kawai uprights from the K500 to K800 offer faster than average repetition. And at least one technician on YouTube states repetition in uprights is a matter of regulation. Pianists, however, agree that uprights are not as fast as grands. What prevents piano makers and parts makers from making fast repetition in uprights universal? Apart from the Russian new action, all those systems seem fairly simple. Do they add up and increase cost and price significantly? Do they make regulation harder? Is consistency achievable with relatively cheap and simple magnets or do you need them to be made with such precision as to make it all too complex for most piano models? I mean, if cheap magnets would do, what stops you from gluing them yourself on your piano's action? If piano students had access to upright pianos with faster repetition, would moving to a grand be an unquestionable necessity?

CrisOliveira

WieWaldi But all in all it seems, owners of uprights don't admit, digitals have an edge in this discipline. They just don't talk about it because it can't be what shouldn't be. (Digital action beating acoustic upright action in a specific point)

That's exactly what I've been thinking recently. I guess most acoustic piano players won't ever consider it a good trade off, exchanging the sonority, the dynamics and the haptics of an upright for the repetition of a digital. But that edge digitals seem to have should not be ignored.

sweelinck There is a tradeoff between risk of double strikes and repetition speed when regulating an upright.

I've checked again some of the fast repetition mechanisms. The video of the Japanese technician seems to be lost media, since the only link I could find sent me to a deleted YT account. If I remember correctly, that mechanism works by repelling the hammer back. I'd imagine that mechanism is not so prone to double strikes, but I don't know of brands adopting such approach, so the drawbacks must outweigh the benefits. Both Feurich and Seiler's mechanisms work by pushing the jack back into place. I would think such approach is more prone to double strikes, considering the jack will go back supporting the hammer sooner, which I suppose is easier for grand piano actions to deal with, because of gravity. But as I said once, trust me not, I'm no engineer.

Feurich:

Seiler:

I wonder how easy it would be to retrofit a piano with those mechanisms. I imagine it'd be quite easy for someone experienced in it, but an inexperienced technician might make a mess out of it.

EDIT:
I've just found this by chance. Someone named Pasquale Bafunno patented a rather complex upright action with repetition mechanism.

pianoloverus

WieWaldi I wonder why there is so little information in the wide internet about uprights and fast repetitions. Or more critical: fast and faint repetitons. In my theory, fast repetions must be loud, if the action requires to reset the key completely - or almost completely.

With my digital I can comfortable tremolo octaves and do this at a lower volume than my normal playing. With a little practice, I became quite easy, actually. I doubt an upright is capable of doing the same.

Only hint I found so far, is this video: At 14:20 Yacine does some tremolos on an upright action (NV6) and admits to have more control with the grand action (NV12 right next to him). But all in all it seems, owners of uprights don't admit, digitals have an edge in this discipline. They just don't talk about it because it can't be what shouldn't be. (Digital action beating acoustic upright action in a specific point)

Repetitions normally normally refer to repetitions the same note not tremolos using two different notes. So I don't think the discussion of repetitions and tremolos belong together. And because the notes alternate in a tremolo, the repetition speed doesn't have to be particularly fast compared to repetitions the same note.
There is no reason why the notes in a tremolo or in repeated notes have to be loud.
There are many different kinds of action on digital pianos. It's possible one might find it easier to do tremolos on a particular digital vs. an acoustic upright, but that could also be a result of other factors like the volume setting. Even if it is really easier to do tremolos on a digital, I think tremolos are a small part of technique so maybe that's why it doesn't seem to be mentioned. I can't imagine a salesperson telling a customer that they should choose a digital vs. an upright because tremolos or repeated notes are easier even if that's true.

CrisOliveira

pianoloverus There are many different kinds of action on digital pianos. It's possible one might find it easier to do tremolos on a particular digital vs. an acoustic upright, but that could also be a result of other factors like the volume setting. Even if it is really easier to do tremolos on a digital, I think tremolos are a small part of technique so maybe that's why it doesn't seem to be mentioned. I can't imagine a salesperson telling a customer that they should choose a digital vs. an upright because tremolos or repeated notes are easier even if that's true.

Like I've said: most pianists won't trade an upright for a digital. Unless it's Stu Harrison.
Digital pianos will have faster repetition if they feature triple mechanical sensor. Double sensor ones are usually out. Theoretically, optical and magnetic sensors are also capable of faster repetition, but that will depend on the design: if what's sensed is the hammer, then probably repetition will depend on the action; if it senses key height, then programming will determine it.

WieWaldi

CrisOliveira if what's sensed is the hammer, then probably repetition will depend on the action

I am 100% sure, on Kawai's RH-3 this is the case. (Tested it)

CrisOliveira

WieWaldi
I forgot to mention optical and magnetic sensors are usually found in hybrid and silent pianos. RHIII is sensed by the hammer, but it's a triple mechanical sensor. Non-hybrid digital actions commonly sense the hammer (although not all).

WieWaldi

CrisOliveira I don't think optical and magnetic sensors are superior over mechanical ones. Maybe in longevity, as they don't have wear and tear. It's just in an acoustic action, a mechanical sensor would impair the mechanics when played in acoustic mode. Hybrids? I could imagine customers want the action to as similar as possible to that of an acoustic/silent.

sweelinck

CrisOliveira I've checked again some of the fast repetition mechanisms. The video of the Japanese technician seems to be lost media, since the only link I could find sent me to a deleted YT account. If I remember correctly, that mechanism works by repelling the hammer back.

Those are actions by Steingraeber and Seiler that use magnets, or by Sauter that use springs for that effect. These designs may have tradeoffs for having those features.

There also is the the Fandrich upright action.

The Kawai design will not achieve the repetition speed of those actions, but is just designed to try to optimize or improve on what can be with a conventional design.

WieWaldi But all in all it seems, owners of uprights don't admit, digitals have an edge in this discipline.

Many upright owners do not own DPs. My digital piano has a faster action than my upright. But the DP still has an action inferior to the upright action overall, and not the same connection between touch and tone.

CrisOliveira

I'm in no condition to buy an acoustic piano right now, but once my situation improves, that's something I'll consider. However, it won't be anything fancy. Maybe a 2nd hand Ritmüller, or even some stencil brand. There's this omnipresent brand here called Essenfelder, an once bankrupt company which turned into a stencil piano supplier, but I don't know who really makes their pianos. I fear the time when I'll not be able to fix my digital piano by adding graphite to the contacts. I'm sure one can rely more on a piano technician's ears that on those of an electronics technician. And no matter how much I geek out in the forum, I won't benefit from an uber fast action. I would like to be able to repeat notes without taking the key back to resting position, but I'm sure I can adapt.

sweelinck

Some may prefer a DP with a seesaw action to an upright action.

CrisOliveira

I took my questions to PW tuner-technicians section and they told me a good and well cared upright piano can have very good repetition. I was also told that the Fandrich mechanism is really good and it can be installed in a WNG action. However, I'm unlikely to find those things here, even though local technicians use imported parts, whether such parts are from Germany, China or wherever.

I know a local dealer and often look at his ads. But it's too soon to go bother him.

Seeker

CrisOliveira This Russian dude has invented an action featuring what looks like a repetition lever, but I can't understand Russian.

I couldn't see enough of the details in his videos to comprehend how he achieved what he did, but the results are impressive. If any of you have the skill to explain, I'm interested. I wonder how difficult it would be to retrofit an existing upright action with his additions. Could be an interesting project.

CrisOliveira

Seeker
I believe his mechanism replaces a good portion of the action. It's not simply something he is adding to it.

Josephine
Thanks for the reply, Josephine. I hope I'll have similar luck.

sweelinck

Josephine One of my uprights has a repetition mechanism by the way. It's a Thürmer from 1903.

All standard uprights have a jack spring to enable repetition. Are you referring to a separate spring?

Seeker

Josephine Thanks for the pictures. The spring thing looks simple enough, but I bet it really does help repetition speed. Please keep us posted.
One other thing: I see three bushings. Have you figured out a way to tell if any need re-pinning? Given the age, my bet is that none of them are tight, but how even things will feel is going to be determined, at least in part, by consistency in the pinning.
Good luck with your project.

Josephine

Seeker

Most bushings are still good, a few are tight actually. I wrote down which parts, so I'll take a look at that later. But it looks like it doesn't need repinning. I do think I have to replace the keybushings. It not really bad, I can't move the keys a lot to the sides, but I saw that someone turned multiple front rail pins in the past, so that's a sign.

sweelinck

Interesting. It looks minimal enough not to compromise touch control when playing softly, which is an aspect some have critiqued with some of the newer upright actions that use springs or magnets to enhance repetition.