Pianotech

Today I worked on a "restored" Steinway 9" grand.  This piano has Renner parts and the rocker arms were replaced with capstans.
The down weight was 65 to 70 grams.  The keys had up to 9 weights in the bass with little room for more.
Obviously there is a serious geometry problem.
Has anyone worked on a similar piano with any good results?

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Blaine Hebert RPT
Duarte CA
(626) 795-5170
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From the picture, it would appear the current key ratio doesn't come close to a 2:1 ratio, given the new location of the capstans. Also, the wippen heel/capstan location may not be ideal either. It looks as though the wippen heel needs to be extended and the capstan lowered. These are areas I would consider first.

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Rick Butler RPT
The Butler School of Piano Technology
Bowie MD
240 396 7480
RickRickRickRickRick
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Blaine,

Success, absolutely, but the conversion requires special know-how. Purists will say that the original rocker system should  have been left alone. But that is a conversation for another thread.

You say you worked on the piano. Just tuned, touched up regulation, voiced? In any case, is the owner complaining? I assume that the excessive DW of 65 - 70 g represents heavy weight (and excessive key leads) in all sections of the scale. This being the case, clearly something is wrong.

Rocker arm conversions require special attention, especially at the capstan top to wippen heel interface; not only the fore and aft location, but the z dimension as well (relates to depth of wip heel and height of capstan block pedestal and the magic line). Are you planning to dismantle the action to investigate further? Are you contemplating a fix? If so, the job would likely be extensive and expensive.

The key ratio (for vastly general purposes) should be ~0.50:1 (typically a bit shorter at 0.048:1) for traveling distance purposes (sometimes acceptably referred to by its inverse of 2:1, but technically that relates to mechanical advantage). But even these benchmark dimensions are subject to tweaking a bit in order to get the whole thing working with (more or less) acceptable and expected regulation specs.

The knuckle location is also a very significant parameter. The replaced Renner shank may be carrying a short-distance knuckle of only 15.5 mm from the center pin. This would contribute to a heavy touch. 

Given a correct key ratio, a corrected capstan pedestal block height, a corrected knuckle location, the overall action ratio will fall in line to ~5:1, which is something of a standard. If desired, a more advanced and customized approach seeking a higher AR, would eventuate in a shallower touch (still with acceptable aftertouch), but that would require lighter hammers. Higher ratio actions with lighter hammers are snappier. Many vintage Steinways were built this way. Then there is the whole inertia thing, but we're not going there right now.

Anyway, following either the standard AR route or the higher ratio route, and finished out with appropriate hammer weights, rocker arm conversions can be reworked to an acceptable performance level. But it's a big job.

Good luck.

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Nick Gravagne, RPT
Mechanical Engineering
Nick Gravagne Products
Strawberry, AZ 85544
gravagnegang@att.net
928-476-4143
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Original Message:
Sent: 09-08-2022 06:07
From: Rick Butler
Subject: 1866 Steinwayaction geometry

From the picture, it would appear the current key ratio doesn't come close to a 2:1 ratio, given the new location of the capstans. Also, the wippen heel/capstan location may not be ideal either. It looks as though the wippen heel needs to be extended and the capstan lowered. These are areas I would consider first.

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Rick Butler RPT
The Butler School of Piano Technology
Bowie MD
240 396 7480
RickRickRickRickRick
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Such excessive leading indicates excessive action ratio. If it more than 5.4 I would lower it . 5.0 is optimal. Could be done by capstan repositioning and whippen hill reversing( Renner allowed it) or extending if needed, or larger knuckle installing. But before any geometry change make sure current dimensions are correct , starting from hammer boring distance.

Alexander Brusilovsky


Original Message:
Sent: 9/8/2022 6:08:00 AM
From: Rick Butler
Subject: RE: 1866 Steinwayaction geometry

From the picture, it would appear the current key ratio doesn't come close to a 2:1 ratio, given the new location of the capstans. Also, the wippen heel/capstan location may not be ideal either. It looks as though the wippen heel needs to be extended and the capstan lowered. These are areas I would consider first.

------------------------------
Rick Butler RPT
The Butler School of Piano Technology
Bowie MD
240 396 7480
RickRickRickRickRick
------------------------------

Very informative post, Bill.

But wow, a key ratio of 70%. I've never seen this, but of course you would know, given your vast research. Our latest successes with rocker arm conversions were on an in-shop Bechstein C grand, and a consultation with a colleague, also with a Bechstein grand. In both cases the results were excellent. However, the original key ratio was close enough for a reasonable capstan relocation, yet special care  had to be taken to work out the capstan block height and the wip heel position. Of course, the knuckle location and hammer weights were carefully taken into account.

i don't  know how long key number 44 is on Blaine's old Steinway, but if it's close to, say, 300 mm, a 70% key ratio would place the capstan at 210 mm behind the balance pin, or 60 mm behind a 50% ratio. A standard wippen could not work, even given a max forward heel location.

Still, it would be an interesting investigation to see just how far modified replacement parts and various geometries could be taken to ameliorate the worst effects of simply throwing new parts on. From you post, however, very light hammers and a shallower key dip would be inevitable outcomes in any case.

Also, as you say,

"If conservation is desired you need to use the very light hammer and the original action, and it will work properly and be playable. But it is an antique piano, with a key dip closer to its contemporaries Broadwood, Erard, Chickering etc."

Your class on this subject sounds interesting. Ever thought of going on the Piano Tech Radio hour with host Eathan Janney? I would be sitting front row up center :)

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Nick Gravagne, RPT
Mechanical Engineering
Nick Gravagne Products
Strawberry, AZ 85544
gravagnegang@att.net
928-476-4143
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Original Message:
Sent: 09-08-2022 11:04
From: William Shull
Subject: 1866 Steinwayaction geometry

Hi Blaine,

My convention class on best practices, early Steinway grand restoration extensively addressed this subject.

The wood frame indicates 1869 or earlier.  Rockers were also original to the action.  The stack elevation is higher than nmodern Steinway.  But the big difference is the key, which, rather than 2-1 ratio {50%) is closer to 70%.   This requires an extremely  light hammer.  Merely relocating the capstan will not make enough difference.

I have documented many of these original actions and found that indeed, Steinway used very light hammers, lighter that what we can usually order.   Ray at Ronsen Hammer has made custom sets but he must be given the data - and these hammers won't look like your typical concert grand hammer!

The original key ratio was much lower, resulting in a dip of closer to 8mm.

Your chapter could have me present if they're interested in fleshing this out with photos and actual data etc.     

There are many rebuilds just like this, beautiful but complete failures.

Many restorers use key makers like David Rubenstein to solve the fundamental key ratio problem.  David sets the keys to a 50% ratio - or whatever is requested.  As many of these old key sets are deteriorated and are also less beefy anyway,  this cuts to the heart of the problem, and is recommended for this action.

If conservation is desired you need to use the very light hammer and the original action, and it will work properly and be playable.  But it is an antique piano, with a key dip closer to its contemporaries Broadwood, Erard, Chickering etc.

Regards,

Bill

Bill Shull, RPT, M.Mus.

bdshull@aol.com

www.shullpiano.com

www.periodpiano.org

909 796-4226

Sent from my iPhone

Original Message:
Sent: 9/8/2022 1:30:00 PM
From: Nicholas Gravagne
Subject: RE: 1866 Steinwayaction geometry

Very informative post, Bill.

But wow, a key ratio of 70%. I've never seen this, but of course you would know, given your vast research. Our latest successes with rocker arm conversions were on an in-shop Bechstein C grand, and a consultation with a colleague, also with a Bechstein grand. In both cases the results were excellent. However, the original key ratio was close enough for a reasonable capstan relocation, yet special care  had to be taken to work out the capstan block height and the wip heel position. Of course, the knuckle location and hammer weights were carefully taken into account.

i don't  know how long key number 44 is on Blaine's old Steinway, but if it's close to, say, 300 mm, a 70% key ratio would place the capstan at 210 mm behind the balance pin, or 60 mm behind a 50% ratio. A standard wippen could not work, even given a max forward heel location.

Still, it would be an interesting investigation to see just how far modified replacement parts and various geometries could be taken to ameliorate the worst effects of simply throwing new parts on. From you post, however, very light hammers and a shallower key dip would be inevitable outcomes in any case.

Also, as you say,

"If conservation is desired you need to use the very light hammer and the original action, and it will work properly and be playable. But it is an antique piano, with a key dip closer to its contemporaries Broadwood, Erard, Chickering etc."

Your class on this subject sounds interesting. Ever thought of going on the Piano Tech Radio hour with host Eathan Janney? I would be sitting front row up center :)

------------------------------
Nick Gravagne, RPT
Mechanical Engineering
Nick Gravagne Products
Strawberry, AZ 85544
gravagnegang@att.net
928-476-4143
------------------------------

Hi Blaine,
Our shop has completed redesign and built everything in the action compartment for this era of instrument many times. I agree with Nick and others that the key ratio should be updated to about 0.50. A new keyset is about the only practical way to handle this.  For this age of piano we'd normally do a complete build, new keyframe, keyset and new stack.

The piano could take a new wood rail Renner action stack, or a more traditional brass rail Steinway stack, we've done both.

I can run the action geometry analysis on our system if you like, it's a free service.  https://www.reyburn.com/geometry.html

Best regards,

-Dean

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Dean Reyburn, RPT
Reyburn Pianoworks
Reyburn CyberTuner
1-616-498-9854
dean@reyburn.com
www.reyburnpianoworks.com
www.cybertuner.com
www.reyburntools.com
Facebook: www.facebook.com/dean.reyburn
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I have only examined and tuned this piano, but I will see it again at the dealer next Wednesday.
I will report on the action geometry and will proceed from there.
Many thanks for the replies. 
This is a subject I had carefully avoided, but it is now in my lap and I guess its time to find out what a Stanwood is.

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Blaine Hebert RPT
Duarte CA
(626) 795-5170
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Original Message:
Sent: 09-09-2022 12:13
From: Dean Reyburn
Subject: 1866 Steinwayaction geometry

Hi Blaine,
Our shop has completed redesign and built everything in the action compartment for this era of instrument many times. I agree with Nick and others that the key ratio should be updated to about 0.50. A new keyset is about the only practical way to handle this.  For this age of piano we'd normally do a complete build, new keyframe, keyset and new stack.

The piano could take a new wood rail Renner action stack, or a more traditional brass rail Steinway stack, we've done both.

I can run the action geometry analysis on our system if you like, it's a free service.  https://www.reyburn.com/geometry.html

Best regards,

-Dean

------------------------------
Dean Reyburn, RPT
Reyburn Pianoworks
Reyburn CyberTuner
1-616-498-9854
dean@reyburn.com
www.reyburnpianoworks.com
www.cybertuner.com
www.reyburntools.com
Facebook: www.facebook.com/dean.reyburn
------------------------------

Hi Blaine,

Here is a solution I've used many times with 100% success.  Lot's of skill sets involved but no Rocket Science so you can keep your feet on the ground!

You identify two abnormalities - high down weight and many key leads. This is a classic expression of poorly matched Hammer weight and ratio levels. With a good match the down weight will be normal and the amount of key leads will be normal.

One choice would be to lower the Ratio to match the present hammer weight level and keep the hammers and shanks (and repetitions) if they are in good condition and producing good tone. Always wise to measure all the hammer weights by tipping them onto a digital scale using the Strike Weight method. Put the data on a graph/chart with reference scales overlaid to judge the weight quality and make decisions about smoothing them out using specifications made with a splining tool or using one of the standard scales if that works.

To bring the Ratio down, by moving the capstan line, start by mocking up a new capstan position on C4 #40. First you want to codify the key leading on your sample note by removing the C4 key stick and tipping it onto a digital scale using the Front Weight method. Temporarily weigh off the key to make a normal medium Front Weight for C4 with is 27 grams.

Install a shank/hammer that represents what you think will be a good final level according to the data analysis. Measure Down and Up Weight and calculate Balance Weight. It's going to be really high, I'm guessing in the high 40s. The goal is to reduce the BW to a normal level by moving the capstan line. 38g is a medium Balance Weight. I'm sure you will have to move the capstan towards the Balance Rail as much .400" or more. Drill and install the in your guessed position. Remove the heel and put on a new heel of a height that satisfies the magic line. Regulate and remeasure Down Up Weight and calculate Balance Weight. If you hit 38 then this indicates what the position of the new capstan line might be. If it's still too high move it the line out further. If too low, move it back a little. Fill the first test capstan hole with cross grain plug and drill another hole in the tweaked position.  (I find this more reliably accurate than a capsten boat)  When you hit your target BW check the regulation and make sure it's workable.

Just curious are these key weights original or did someone added more? 
If the Ivory Billed Woodpecker had at it then the new keyset that's a point in favor of a new keyset with modernized balance rail position.

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David Stanwood RPT
Stanwood Piano Innovations Inc.
West Tisbury MA
(508) 693-1583
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