I have a dear client with arthritis in one of her thumbs. She loves to play, but only can play on a piano with a very light touch. Someone from her church gave her a well worn Wurlitzer console that seemed to have the right feel, and after a fair amount of work on the action and key bed, she can now play for an hour at a time. She has begun to play at a nursing home on a Wurlitzer spinet that is in fairly good condition with a normal touch, but after about 5 minutes her joints are in pain. Any suggestions for lightening the touch? The keys are eased and free, and the action lubed and is in good shape. I don't want to try to re-invent this piano only to invite other problems that I will have to address on my time. I didn't give her much hope.
Steven

You could try shimming the spring rail so that there is less tension. Use a wedge-shaped washer to tilt the bottom edge towards the rear of the piano. This may not make a big difference, but it is probably the easiest reversible way to make any uniform reduction in touchweight.

Do you have a gram weight set to check the downweight of the console to compair with the spinet? It will help you develop a target for her.
You can try making the damper lift with keys as late in the key stroke as possible.
If there is lead in the spinet keys (hammer side of balance rail) you may be able to remove it or some if it as the additional drop action parts should safely return the key after release.

Changing the leverage isn't that hard to do. The quickest and safest way to do it is to alter placement of the fulcrum, aka the balance rail.

Using half punchings with the front cut off--the half closest to the player--and the other half lightly glued to the key is one way to go. The method suggested to me during a seminar at a recent conference is:

Remove keys
Dab a spot of water soluble type glue just behind the balance rail hole
Replace each key after applying glue
Once all keys are back on keyframe, remove keys one at a time, beginning with the first-glued end
Cut punching in half, remove non-glued portion
Replace keys

Other people have suggested glued paper packing-tape shims underneath the back of the BR punching.

While I haven't done a whole piano, I have experimented enough with an action model to know that the weight savings is substantial. I was shown this method recently, and I look forward to trying it in a real life situation.

To make the action heavier, the punching or shim would be on the forward side of the balance rail pin.

I've changed damper timing, and it works, but it can have negative effects on sustain, especially in the longer strings where the string might end up contacting the damper after a firm key blow.

Thanks for sharing this, I recently had a customer who played a well worn Kimball for many years, bought a new high quality studio piano, and is having to readjust. Perhaps this would help ease him into the seemingly stiffer touch.

Piannaman,
At the California Conference I purchased a set of felt balance rail punchings that were cut specifically for this application from Piano Forte Supply.
Have not had time to experiment yet. Thanks for your input.

Gene,

Jurgen sells those, but I haven't used them yet either. He sells excellent products. I've used several sets of the conical Wurzen felt front rail punchings, and they're a great item.

The only advantage to using the existing ones--assuming they're in decent shape--is that they're already compressed and won't require re-levelling the keys.

Hallo all

Not being a tech but a layman interested in the subject, I cannot contribute anything to this but would like to ask a few questions.

1. Are there any references/articles describing this sometimes also called "half-moon" technique?
The seminar[/b] which piannaman[/b] is referring to in his first contributions, could that be the "6 day Stanwood course", where in the section " Installing the PTD", there is a subject called: "A special method for modifying balance rail punchings in order to effect ratio and make the action lighter or heavier" see: http://www.stanwoodpiano.com/6DAYCOURSE.html?
2. Is a complete regulation needed afterwards?
3. I suppose this technique does not change in any way the dynamic properties of the action mechanism?
4. Would't using the pre-cut "Accelerated" Wurzen punching where Gene[/b] is referring to, not be more accurate than the glue/cut method piannaman[/b] has learned in the seminar. I would assume that if one cuts oneself the punching this needs more attention as to get them cut as precisely than when these are pre-cut "industrially"?
I also noticed (see picture in this link: http://www.pianofortesupply.com/cresbalpunch.html, that the "Crescendo" punchings are not exactly cut in 1/2, but that merely a 20 to 25% is cut away? Wouldn't this allow an easier positioning of the punching around the balance pin?

Many thanks,

schwammerl.

If the key ratio is slightly altered this would be changing one of the dynamic properties of the action?
Does the thickness of the round felt punching play a roll? Can more paper and less felt move the fulcrum closer to the keyslip?
The way I understand this is the original design key ratio measurement is altered slightly with the round - uncut balance rail punchings as when the key is depressed the fulcrum is not at the base of the balance rail pin but rather at the edge of the balance rail punching. Trimming the edge of the punching gets the fulcrum closer to where it should be based on original design. Possibly similar to the SS Accelerated action?
As for precision even if the tolerance were held to +/- .001 there would be other factors at the balance rail and keys that would make holding this tolerance not worth the effort.
I will observe the Wurzen set before installation but it is my guess that their symmetry varies to some degree.

Schwammerl,

No, I didn't take the Stanwood course...I'd like to, though.

I took a class at the recent PTG conference in San Francisco, put on by Pianotek. Much of the class was based on STanwood's teachings. Unfortunately, I had to miss much of it, as it was my chapter putting on the conference, and I was called into duty early in the afternoon portion of the class.

According to people who have tried this method, no regulation should be needed. I admit to not having tried it yet, but I look forward to hearing the next complaint of "my action's too heavy...can you do something about it?"

As to the percentage of punching cut away, I think that depends on the effect you want it to have. The bigger the cut, the bigger the change in leverage.

If you have an action model, check it out.

Hello Steven

piannaman has the solution right there. I have used this technique, and I have found it to be great for elderly ppl with arthritis. You just take the felt punchings off the balance rail and cut them in half, putting them back in place with the 'half felt punching' on the action side of the BR.That along with a damper reg to lift the dampers later in the key dip will do a perfect job!
Though I do have to disagree with the regulation thing.....there would be no harm in at least checking the regulation after this!

The old woman will think you are a 'minor' deity!!!!

Good Luck

best Regards

Mark

Thanks for all your help. I was not aware of this simple fix. I will present it to my client as soon as I figure out the approximate man hours it will take. Can I assume this technique will work on pianos that need the touch beefed up a little? I would put the punching halves on the front side of the keys, I assume.

Stephen,

According to reliable sources (and my own tests on action models), it indeed works both ways!

Could altering the fulcrum point in the descibed way be the "final solution" on my Förster 125 G upright? The keys are fairly short - the depth of the piano is only 59 cm

What negative effects would follow making the touch lighter? Less power?

Without seeing your piano Jan-Erik I would say that this should of course work. And if the piano is properly regulated, no loss of power should occur as you will not be altering either the key dip or the blow distance....although maybe someone will pick me up on this if I am incorrect.

Regards

Mark

I got very interested in the suggested modification.

The keys on my piano are mooving very freely. That can be determined by pressing the soft pedal and touching the keys. Within the loose movement there is no resistance other than the keys' own mass.

Had a look at the keys, without removing them, only lifted the front panel and fallboard.

Looked like the balance rail had the fulcrum point machined in its profile. I could see paper shims under the keys, nothing else appeared.

I do not understand what kind of "punchings" you are talking about

The balance pins protruded closer to the front of the oval slots, which are clad with leather on both sides. I imagine the balance rail thus could be mooved 3 mm backwards, and there would still be free space in the slots.

Although the keys are very short I doubt such a minor alteration of the fulcrum point would have any essential influence on the dynamic touch weight.

I will give the leverage measures later. But can anyone explain why modern pianos are not as deep are hte old ones. Mostly the depth is under 60 cm, which has a negative influence on key lenght. Grand manufacturers use to boost about how long keys the have designed....

Hi Dave-
is your balance rail punching method actually reducing downweight?
Maybe at one of these upcoming chapter meetings we could do some quantitative analysis. You bring the punchings and gram weights, Ill bring the action model and a spreadsheet.

I think it all depends on the severity of the arthritis: are their fingers and/or carpals really stiff. In severe cases, they wouln't be using much power- in this case I guess having less aftertouch would be also desirable in reducing fatigue. I might add .03 - .04, and depending on jack clearance adjust letoff. This way the player needs less finger extention to play, and wouldn't play firm enough to make more than a couple of bobbly notes. -Rick B.

Here are the measures:

White keys: from pilot to key edge 335 mm
from pilot to fulcrum 135 mm
Black keys: from pilot to end 275 mm
from pilot to fulcrum 115 mm

The lever ratio (outer part to inner part) of white keys is 0,6585, of black 0,7187. As you normally do not hit the white keys at the egde but deeper tte ratios are closer to each other.

Mooving the fulcrum point by 3 mm towards the action would change the ratios to 0,6055 and 0,6666. A difference of 4 percent only.

This should be multiplied with other ratios of the actions levers, but the final result will nevertheless be a 4 % decrease of touch weight - purely mathematically.

But if the fulcrum point could be adjusted 5 mm inwards, the differnce would be 7 percent.

Jan-Erik,

Sorry for my lack of attention to this thread...been kinda busy lately.

There are in all likelihood felt punchings between the key and the paper punchings, or else it would be mighty noisy when you play!

You can do a test for a change in touchweight by slipping a piece of business card under the punching stack up against the balance rail pin. Try it on both sides of the pin(back and front), and notice the difference.

Rick, I have not done a weight analysis of the procedure, but have checked out the feel on an action model, and the difference is noticeable. Doing a chapter technical on this would be interesting.

The dampers as Dave said. If they lift even slightly early the added stress wears out the hands quickly. The hammer and action need to have the inertia (built up kinentic energy) when the damper starts to lift or the pianist has to force the hammer to the string through the damper. Not good for weak hurting hands

Being an outsider here and reading this thread...it's very interesting...keep it going. Would really be interested in your findings...

Would not the half punchings wear, or get depressed faster than full punchings?

So if possible, you should better moove the whole rail? Or may be take both measures for increased effect?

Does this have any more than theoretical influence on damper lifting? And key balancing in general?

This thread has appeared at just the right time--one of my tuning customers asked me to help her lighten up the action of her Kawai KG-2 (1987). So far, I've done the following:

-polish capstan heads, which had quite a lot of verdigris
-Protek all center pins
-ease key bushings, which were pretty snug

...and the action is still so heavy, my whole set of gram weights will not cause one key to budge. Here's several pertinent questions, therefore:

Is it inadvisable, for any reason, to try the half-punching technique on this piano?

How about shaving the hammers (something I've never done before), and what's the best way to make sure the amount of material being removed is uniform on each hammer?

When retarding damper engagement, is there a rule-of-thumb for knowing how late is "too late"?

Hello Jim
KG-2? Like I said on another thread, piano model numbers are not my forte....but if the balance rail in this piano utilizes the common round,flat felt punchings, then I could see no reason why you would not use the 'half punching technique'.
Regarding damper engagment, the dampers should begin to lift when the hammer is between one half and two thirds of the way to the string. In other words, let's say your blow distance is - for the sake of simplicity - 48mm. The earliest your dampers should be beginning to lift is when the hammer has travelled 24mm of the total 48mm. The latest they should lift is when the hammer has travelled 32mm of the total 48. And the later you have them lifting, the lighter will be the touch for your customer.

hope this helps

Best Regards

Mark

This is something that works if you just need a little bit of a nudge in the action ratio. It's not a big change. When I have used it, I have gotten in the range of 4-5 grams of downweight change. It's a nice effect for not having to do alot of work. That was shimming the back edge of the key. It will probably depend on the action somewhat.

Jim, it sounds like you are off to a good start with your approach. Even if you have proteked the action centers, you should check the friction levels. The pinning might still be tight. Beyond that, you could try putting teflon powder on the knuckles. I have had that alone make for around 10 grams of friction.

Whenever you have a high downweight, you should check the upweights. This will tell you whether you have a ratio/weighting problem, or a friction problem. Downweight alone doesn't tell you much.

Mark,

A KG2 is a Kawai 5'10" grand. Nice pianos, but the actions could be heavy feeling, particularly if overburdened with friction.

IMHO:

as Roy says, check pinning, and teflon knuckles

Lubricate keypins with Protek or McLube

Regulate blow distance, let-off, drop and repetition springs
Excessive letoff distance can diminish power and control.
Overly strong rep springs can increase weighty feel and allow for unwanted "kick back" in the key on hammer's release from backcheck)

Then you might experiment a bit with 1/2 balance rail punchings to see what kind of before/after difference you can get.

Damper timing is effective, but has side effects. I've delayed damper lift in a couple of grands, and it's worked out okay, but I've had to tweak other aspects of pedal operation. There isn't much margin for error if you do this, but at least you can reverse it.

I've done it by bending spoons, and by pushing the wires deeper into the blocks. Bending the spoons is FAR easier.

Shaping hammers is the one thing mentioned that is NOT reversible. If you're not comfortable with it, I wouldn't practice on a customer's nice grand piano!

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Jan-Erik,

Can't say for sure about punching depression, but I've heard there are really few drawbacks to it.

Moving the whole rail would be extremely difficult, much harder than the 1/2 hour punching slicing operation. And it would change the action ratio in a big way,


"Would not the half punchings wear, or get depressed faster than full punchings?

So if possible, you should better moove the whole rail? Or may be take both measures for increased effect?

Does this have any more than theoretical influence on damper lifting? And key balancing in general? "

Just wanted to revive this thread for a progress report...

My customer says "the piano (a Kawai KG-2 grand) plays better than it did when it was brand new!" That's after doing the following as suggested here, in addition to polishing the capstans, applying Protek, & easing key bushings:

-teflon powder on knuckles
-retard damper timing (dampers were lifting much too early in hammer travel, for some reason)
-ease balance rail pin holes (most of which I found were swollen enough to be major contributors to the problem)

All that, combined, finally did the trick, so I didn't have to attempt the balance rail punching-trimming technique (I didn't really feel like experimenting on a customer's piano anyway, so I'll try it on one of my own first). Thanks to all for the helpful tips.

Cool, Jim. Thanks for the update.

I always try lubrication and regulation first, and they usually make a huge difference in control and pereception of touchweight to the player.

Weird that the damper timing was so far off, but that can really contribute to sluggish feel.

I like working on Kawai KG, GS, and RX series pianos. They revitalize well, even after a few years of neglect.