Action ratios can be changed to accommodate heavier hammers without making a new keyset. You can go to a 17 mm knuckle, move the capstan 3 mm (same effect as a 1 mm move of the knuckle) or both. I do this routinely.
An action ratio assessment is not necessary to determine this and most AR measurements are not that accurate. See the previous thread on this topic. You can preset the FWs to some predetermined maximum and then by sampling determine what the hammer weight needs to be and see if the set you want to use will comply. If not then you can change the AR as suggested or go to a lighter hammer, or just taper the set you have more.
Many ways to skin a cat (disgusting saying that one).
But I think the question from Thomas was more to do with the tonal qualities of various hammers. Of the three I tend to use: Ronsen (various types of felt), Renner BP or Abel Natural the Renner and Abel are very similar, especially in the mid range. I find the Abels tend to be a little brighter in the upper end. I don't usually worry about the bass end. Ronsens will be softer than both of those. There is some variation in sets from the same maker but mostly they are pretty close. Much of that variance will depend on the hammer's profile (felt thickness). Best thing, is to gather samples and listen to them. Midrange and lower treble are the important areas. I tend to chose hammers always for tone and figure out the weight and balance later unless I'm just swapping hammer heads and nothing else, and assuming the action was set up correctly in the first place--not always the case.
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David Love RPT
www.davidlovepianos.comdavidlovepianos@comcast.net415 407 8320
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Original Message:
Sent: 08-29-2025 19:59
From: Parker Leigh
Subject: Hammers: out-of-the-box measurements
I would start by measuring the key ratio. Erwin's guage is handy for this, while not as detailed as the Stanwood Protocol. Older pianos tended to
have higher key ratios and lighter hammers less firmly pressed. For pianos under 30 years old you can use a 'modern' hammer from multiple
suppliers. A 1909 Steinway would have had very light hammers with full tapering in line with the high key ratio. Unless you are installing a new modern
style keyset with lower action ratio keep this in mind.
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Parker Leigh RPT
Winchester VA
(540) 722-3865
Original Message:
Sent: 08-29-2025 18:16
From: Thomas Brantigan
Subject: Hammers: out-of-the-box measurements
This is a great post. Is there anywhere or anyone that can give a generalized view of the different hammers from different suppliers?
Thanks
Tom
Thomas Brantigan
www.pianotraditions.com
All strange wordings and spellings are brought to you by Siri!
Original Message:
Sent: 8/28/2025 12:24:00 PM
From: Richard West
Subject: Hammers: out-of-the-box measurements
Voicing starts with hammer selection. So, how do the various hammer choices/manufacturers that serve the occasional installer of hammers compare? Does one hammer maker consistently produce hard hammers and another produce soft hammers and how do we know which is which? How do the raw physical size and weight affect voicing? Can a person place an order for "hard" hammers, for example? Are there manufacturers that make larger-sized hammers? There seems to be anecdotal information on these issues, but no universal published standards/comparisons.
Perhaps hammer making is a process so fraught with inconsistency, that it's impossible to have standard comparative guides. In that case, how is the field technician able to determine what kind of hammer comes out of the box? How is a technician able to compare with some assurance that the built-in voicing out of the box can be counted on?
How are hammer weight characteristics determined? I know that David Stanwood and others have their own scales, but is there a universal/common scale/set of measurements for weight and size and firmness?
How does a person know a hammer is "heavy" or "light?" right out of the box. Steinway has the current reputation for making heavy hammers. It used to make lighter hammers. Which is the better choice in today's market? I know that technicians can reduce weight via felt/molding reduction. But is this really a desirable thing?
Raw hammers have characteristics that affect voicing. It doesn't seem like much attention is given to that fact. More attention is given to mitigating hammer differences via chemical applications and needling. Of course final determinations have to be tailored to client wishes, as well as the physical environment of each instrument. But knowing what you're working with certainly helps in producing a predictable favorable result.
Richard West
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Richard West RPT
Oro Valley AZ
(402) 570-4409
440richard@gmail.com
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