Return Weight

I Said It

Because it is slow in replies, besides the only problematic thing...

Decreasing the return weight would make it even slower... it's a problem of pre-regulation, background, repetition spring your...

Ok thanks..

A questo punto aspetto il tecnico che mi viene prossima settimana (un altro) perché questo non lo vedo molto avvezzo e sentiamo che dice

P.s my key is 47 cm long

Hi, I watched video number 3, but I would like to make a few observations:

can I view the return weight as a resistance? That is, if the weight were low, around 20 grams, would the key rise more easily during the ascent compared to a return weight of 25 grams, where the key encounters more resistance during the ascent, assuming the same downweight?

what does it mean when a piano has a downweight of 47 grams (low value) and a return weight of 27 grams (very high value), a ratio of 1.78? Considering a Steinway, it should be 52/20 = 2.5

Thank you

Denis

Return weight is not a resistance. It is precisely the difference between down weight and return weight that expresses the "resistance," i.e., the value of friction! If friction is too high, the down weight increases and the return weight decreases. The correct proportion between the two expresses the "health" of the mechanical movement. Every design has its own values which, naturally, must be in the right ratio. This does not have to be strictly logical. Even the required weighting must be uniformly decreasing. Excessive discontinuities in key weighting tell us that an attempt was made to compensate for a resistance that was actually excessive friction, and the cause must be sought.

Hi, by measuring the repetition weight and the let-off weight (in a grand piano), as I recall their ratio should be about 2.5, can I understand if there are also problems in the double escapement (for example, a flat roller)?

Thank you

The causes of excessive friction can be many. Watch my video tutorials

Hi, I have an upright piano, as can be seen in this video below. Is it correct how I measure the aftertouch weight? To explain myself, as can be noticed from the video, the key goes down slowly, but it doesn't reach all the way to the bottom; is that normal?

https://www.dropbox.com/scl/fi/tad1tr2rk3sn99hk5ffau/VID_20240425_101936.mp4?rlkey=aprrwghykcbugor3to074knjv&st=ur8bw4w5&dl=0

Thank you

Denis

It can be quite normal because during the descent, the key meets the damper (in fact, it must be measured with the sustain pedal depressed) and also encounters the resistance of the escapement lever under the hammer butt. However, if the differences with and without are significant, there is something wrong with the escapement lever pivot or the damper lever pivot, or even the damper cap may have formed a hole in the felt that receives it

Hi @pianoexpert, I have posted the video below (recorded with an upright piano) to find out if you think it is normal for there to be such a high difference in travel between when I apply weight and use the sustain pedal and when I do not use the pedal?

Given the perhaps excessive travel, do you believe there is: "something wrong with the escapement lever pivot or the damper lever pivot, or even that the damper felt lifter may have formed a dent in the felt it rests on"?

https://www.dropbox.com/scl/fi/weie1wtc7cb48xp8fyrk1/VID_20240425_161721.mp4?rlkey=0lk7x967lemw35kazxq9bic98&st=8h8qs3i1&dl=0

Thanks

all hypotheses from a distance. Verify them or have them verified

Hi, in your opinion, does it make logical sense to understand the quality of a digital keyboard by measuring the downweight and return weight?

Where the downweight should be around 55-47 grams, and the return weight from 25-20 grams.

Thank you for your answers

Denis

The digital keyboard can have various assistance systems such as springs etc....

It makes sense if the digital action is designed to simulate that of a grand piano.

Today there are digitals with very complex actions even in wood (see Kawai MP11SE), and other actions like Yamaha's GH3 or GrandTouch-S, etc. etc.

With these actions, it makes sense to understand how similar they actually are (regarding weight) compared to the action of an acoustic piano.

Hi, one piece of information is not clear to me: if I buy a new piano and the downweight and let-off weight values are around 54 grams / 22 grams. Over time, will the downweight decrease due to increased wear on the flanges, and will the let-off weight instead increase?

I remember that friction is measured as (downweight - let-off weight) / 2

Thank you

Denis

Yes... but it's all relative. I don't think a new piano that has 54/22 works well. One must see, then, "which" piano. It is not certain that what you say will happen. The mechanical pins must be checked