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A seven yr old instrument, played 15 hrs a week is due for complete grand regulation, friction release, lubrication and all included tasks.

Upwards of 2000 dollars for a thorough job, possibly more.

I have not done complete weight measurements, but doesn't the standard measuring procedure require the user to tap the key frame and if the key moves, record that weight? If the OP is recording the weight that is required to make the key go down without tapping, it will most definitely be higher down and lower up.

Notwithstanding the fact that the player feels the action is too heavy and that should be the final judgement.

Interestingly, one can not deny the need for regulation.

Also interestingly, regulation itself will reduce friction and improve efficiency.

65g DW may go down to 55g DW. That 10g reduction in DW absolutely be transferred to UP and the UP will be in the area of 40G.

I am sure Kawai did not design and build with THAT result in mind.
Are we questioning the OP's measurements? They have stated their proper due diligence more than once.

So, what IS the MISSING piece?

I am curious cinstance, approx what rural area are you in?

The player, albeit 12, is very skilled, and as such knows the touches of many different pianos. Admittedly this is a guess, but I feel a good one. I am not a skilled played, but I have played more than a few Kawai RX-3s, and they are consistently on par with the Steinway B my teacher has, the Lester 7 footer at the church, the Mason Hamlin BB I play sometimes and of course my Baldwin L.

I too will be interested to see how this shakes out!

We bought the piano 4 years ago. We are the first owner, but the piano had sat in the dealer's room for 2 years before we bought it. The action was a little heavy at the beginning, but it certainly feels more heavier now. If it is due for a thorough regulation, I'd be happy to pay for it so that my son can have a piano in top condition to practice with.

Forrest, you are right. The piano sounds great. Even my son's teacher, although very picky, praised our piano during her visit to our home to check it out.

Larry, we lived not very far from you (less than two hours drive), in Hanover of NH.

This is an unfounded presumption. Unless the youth is playing in many competitions in a variety of venues (unlikely at this age) the exposure to a variety of quality and well prepared performance instruments is going to be quite small. Outside of the instrument at home, at the teacher's, and around school (maybe a church too), the exposure to nice instruments or even a variety of different instruments will be quite minimal. This isn't to say there isn't some degree of merit in the observation, it is just to say that at 12 years old it isn't much of an experienced observation. Aside from finding out if the technician did anything to the action (presumably not) I think the change in voicing, which will have been quite bright given the amount of use, only drew more attention to what was already inherent in the action.

In the 1990's I can remember that one could choose a Kawai based on various voicing types... classical, jazz, pop. Funny enough those alleged to be classical were heavier to play with a muddled tone, and the others were light and bright. I remember doing a few competitions on a new "classical" church Kawai and it was horrible to get any dynamic without jumping on the keys.

Be it as it may I won't reiterate what's already be suggested. The need for further examination is apparent. Suffice it to say that voicing down doesn't usually involve changes to touch weight unless this is an unscrupulous technician that lessened the blow distance instead of working with the hammers.

Not the way I was instructed, but I use the Fandrich/Rhodes WeightBench program.

This is my tentative conclusion, as well.



Yes. Reality trumps whatever any of us "experts" may have to say. Reality-oriented behavior will involve actually doing whatever it takes to get a technician on-site rather than expecting additional illumination from the internet. Otherwise, informed speculation vs. uninformed speculation remains . . . speculation



This discussion is hampered by the fact that the issue is much more complex than most of the posters recognize. . .

1)As was mentioned in a previous post, voicing can create the impression of requiring more effort to move the hammer because of the increased dynamic range comes at the pianissimo end of the spectrum. True, it doesn't change either the mass or the leverage or the friction, so any objective objective measurement limited to those parameters would remain the same.

2)Light and heavy are common terms used by pianists to describe their subjective experience. They are not appropriate terms for analysis of the physics of a variable velocity machine. They have led the entire industry down the rabbit-trail of using weight to solve problems that weight won't solve and using weights to diagnose problems that weights can't diagnose.

All true statements. The pianist side of me can only recall maybe one or two Kawai grands I've come across that I really felt at home on. The overwhelming majority of Kawai grands have felt "heavy" to me. Sure, friction could be partially responsible, but I suspect something else. Curious, I just fished out the handout I received during John Rhodes' and Darrell Fandrich's presentation on their Inertial Touch Force calculator to see if they had listed any Kawai samples. Indeed, there are two, and the data they provided explains why I've always felt this way about Kawais, and probably explains the OP's problem.

Kawai RX-6 (ca. 2001):

Action ratio: 5.68
Strike weight average (notes 47-51): 9.8g
Scaled Inertial Touch Force: 281

Kawai SK-6: (ca. 2001):

Action ratio: 5.71
Strike weight average (notes 47-51): 10.4g
Scaled Inertial Touch Force: 315

Both pianos have reasonable action ratios, but very heavy hammers. With respect to the SK-6, the hammer mass would have to be reduced by roughly 1.5g to achieve a "medium" inertial feel, and about 1g for the RX-6.

If I had data from the OP's piano, I could crunch the numbers in less than five minutes, but that would require a local technician to take them.

Very revealing Beethoven. I've felt the same about Kawai instruments in general as well. I only have encountered one 7' grand I thought was quite nice. Not surprisingly it had been rebuilt by a very competent technician. I'm not sure but I wonder where the Shigeru line figures with hammer mass and action ratio against the general production models.

cinstance,
To help determine whether the "heaviness" your son reports feeling when playing the piano is due more to inertia problems or sluggishness-ask him if he notices the heaviness most when playing rapid passages of notes and/or groups of notes loudly or is it heavy with all kinds of playing.

Higher than ideal friction that is low enough to not interfere with soft playing or repeated notes is not noticed as easily as excess mass in the action is noticed with faster playing.

Hi all. Thanks again for continuing the discussion. Larry came to our home today to take a look at the piano. Larry and I spent a good 4 hours, taking measurements and making various adjustments to diagnose the problem. I am very delighted to say that we have found the main causes of the heavy action.

Before I continue, I want to first express my biggest gratitude to Larry for driving 2 hours single way, in not so good weather of New Hampshire, to come to our house to provide the help. Larry is one of the most generous persons I have known. During the four hours, Larry not only took great care to diagnose the problem, but also explained everything to me in great detail. It is almost like taking private hand-on lessons, and I have learned so much from Larry in these several hours.

I am not a piano technician, so I can only do my best to describe with my limited knowledge about piano. First we found that the action indeed is on heavy side, and the friction is quite high. We measured touch weight for all the C's from C1 to C8. The downweight runs consistently above or near 60g (except for c7/c8 which are both 56). The heaviest one is C3 which has 68 gram of downweight. The upweight nubmers are mostly below 30. The highest friction of the C's is from C3, which get a downweight and upweight combination of 68/27. However, the most extreme numbers we got is from E4, which has a combination of 69/20. We also measured some other numbers, like strike weight, action ratio, hammer flange swing, etc.

Since the E4 is the key with the worst numbers, so we took some experimental adjustments to see if we can reduce the friction number. First Larry applied some dry film lubricant to the hammer knuckle, it enhanced the number just a little. Larry then checked the hammer flange swing, and found that it is very sluggish. The dramatic change came after Larry eased the flange pin hole a little, and changed for a new pin. The downweight/upweight numbers went down all the way from 69/20, to a very desirable 54/28. After this, the hammer seems to bounce a little, so Larry loosed jack spring a little which cured the bouncing. It is safe to say that, at least for this one single key, too tight a flange pin is the cause of the heavy touch weight. It is very reasonable to assume that this might be a universal condition for all the keys (although some may not be as tight as the E4), since I recalled last summer, we got 3 stuck keys, which were also caused the tight flange pins.

I am relieved to know that the piano do not have bigger problem, and again, I am so thankful for Larry's kindness and generosity. Before he left, he taught me how to do these adjustments by myself, after knowing that I have mechanical engineering background. Larry is such a great treasure to this forum and pianoworld.com.

I also want to thank everybody for one more time, for all your kind help and the informative discussions.

Cinstance,

Thank You for the kind words.

As I suspected, there was a simple explanation for the issue the family is experiencing. A "full regulation and friction job" may have addressed this but ad a great additional expense and it may not have addressed one item.

Essentially;
Hammer flange pinning was erratic and often far too tight.
Bit too much lost motion at Jack/knuckle.
Rep springs too tight (adjusted to tight hammer flange pinning).

Tri-chord damper felts were puffed below the strings making for a "nudge" coming out of the strings coupled with a true "artistic" slight early lift, contributed to the sense of heaviness.

For Beethoven
Action ratio was 5.7:1
Strike weight at the following notes;
55 8.0g
56 8.1g
57 7.8g
58 8.0g

There was something that was creating a disproportionate increase in down touch weight VS up touch weight for the friction in the hammer flange. I am going to look into this further so that I have fair explanation for it before making any comments.

As a fan of specifics when it comes to diagnosing issues in an action, I find this makes the prescription for the work more focused on the clients needs. This keeps the budget/expectation far more in line.

Slight correction, the E in question was E5, not E4 and yes, it does represent the general range for the piano.

I really enjoyed meeting and spending time with the family. Cistance is an engineer with very strong mechanical background and I enjoyed working with him. Their son is doing extremely well wit his studies and played for us a little bit. He plays very very well. Cistances wife is very charming and supportive of their son.

They have a very nice sounding Kawai. With a little attention, It will give their son many years of enjoyment.

Hi Larry,

Are those strike weight measurements or hammer head weight measurements? WeightBench predicts an action with a 5.7 ratio and an approx. Stanwood curve #6 as having an ITF of 224, which would be considered very light, in terms of inertia. If those are hammer weights, then the strike weights should actually be about 1.8g heavier, and that would result in an ITF of 313, or very high inertia.

If I would have known you were going to see the piano, I would have sent you the specific measurements WB needs to calculate action ratio, because there is probably a fair amount of error unless using their exact measurements. If you end up going back, let me know!

Please, can you explain this to me?
I always understood that when you reduce the DW (less hammers weight, adding leads) it was also decreases UW an equal amount.

Good Morning Beethoven,

I brought my Stanwood table and digital scale. The measurements I listed are strike weight measurements.

Error in my action ratio measurements? Surly you jest.

Would you care to rephrase your question?

Considering I removed a hammer, repetition and several keys and measured them independently, I trust my calculations. It is likely that, from my data, we can determine accurately the numbers you need.

How do you need your numbers?

Lluisci,

The results I provided were from adjusting friction, in this case, reducing. The results are generally what would be expected. There was one issue that was skewing some of Lesong's original the touch weight measurement. When we allowed for that, we arrived at the numbers posted. Lesong did measure correctly BTW.

Greetings,
I have some questions about why a tech would voice a piano with this much unevenness and friction. It appears that the action needs to be repinned and then regulated. In holistic piano care, which an owner of an RX 3 should be seeking, I normally discuss voicing as what I do after I regulate. If the hammer flanges are tightening, pay particular attention to the jacks and repetition levers, too. Tension in them can masquerade as spring problems.

I would also certainly check to see that the sole plate, at the balance rail hole, is no more than 4 mm thick. If it is, then you will have a definite loss of sensitivity and will have a feeling of heaviness.
Regards,

Yep. I have questions about this too but I am not asking them.

This would be one of the most blatant examples;



3 malfunctioning keys tell the story of inspecting all flanges which apparently did not occur to the original tech.

To be fair to the original tech, the client might have suggested a budget that only addressed the 3 sticky keys. I don't think it is fair to assume the tech missed anything.

We should ask the OP.

I also think some restraint and decorum is due.

Exactly. I don’t believe fairness was extended to the original tech along with any of the suggested restraint and decorum.

Not when the initial posting is worded with the implied cause of the problems following voicing the hammer set for tone.



I service over 100 Kawai products annually. Being part of the Kawai Initial Service program tells me that this was the response required below.



The instrument obviously suffers from the lack of a comprehensive preventative maintenance program.

Something that voicing will never remedy. Implying that the instrument became heavy after the voicing procedure is disingenuous when we learn later on mechanical problems in the form of failing mechanics, a year ago,due to excessive friction, or lack of maintenance, whichever way you like it, is the problem.