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Ronsen Low Profile Hammer

  • 1.  Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 07-27-2013 13:17
    Note:  This is a cross posting under a new heading that came from the "Dope or not, Wiekert" subject line. 



    I agree with Fred.  The protocols outline suggest a New York Steinway type lacquer treatment.  I don't see the point then in worrying about whether it's Weikert felt, Bacon felt or Joe's felt.  Once you soak the hammer with lacquer it lessens the importance of what the felt is to begin with.  If you are going to reap the benefits of Weikert felt then it needs to be unadulterated, at least in my opinion.  The problem continues to be too much bulk. 

    As I've mentioned and Fred alludes to, the  profile of the hammer is very important and must work hand in hand with the overall density of the felt.  A lower density felt either from pressing or from the starting point of the sheet must be profiled appropriately to match.  These two aspects of hammer making must work hand in hand.  A bulky lower density hammer will always need lacquer, always.  However, a trim, lower density felt will not.  (Similarly, a high density felt, say from heat pressing, will be uncontrollable in a low profile configuration.  In that case a higher profile will be the more appropriate choice--more on this another time).  The closer proximity of the molding to the strike point gives the hammer that bottom it needs without having to compensate by using lacquer and deal with the side effects associated with that.  I've attached (or will attach) a series of photos from a presentation I did pointing out some stark differences in profile that exist between current iterations and historic hammers.  One photo compares a 16 lb Weikert with an original Steinway hammer and another compares note 40 between a 16 lb hammer and the newly dimensioned hammers that I would advocate.  These photos of the Weikert 16lb hammer are hammers that I removed from a piano (relatively new hammers) because they simply did not sound good (customer opinion and mine too).  The hammers were very heavy, very bulky, infused with lacquer and sounded dead, lacking clarity throughout but especially in the upper part of the piano.  I replaced them with another Weikert hammer that was made to my specifications (see below).  Completely different response, clarity, power, high partial development as needed.  Removing all that weight also reaped benefits in terms of touchweight dynamics.

    The hammer design that I have been asking Ray to produce for me can be ordered from Ronsen.  It is currently referred to as the Weikert Low Profile Hammer.  If you simply contact Ray and ask him for that or the hammer that I have designed he will know what you are talking about and can make it.  The features and important areas are as follows.

    1.  The hammers are profiled to a specific dimension through the set.  This is designed to be matched with the overall density of the felt and the style of pressing.  A match between these two aspects (sheet density and profile) is critical. 
    2.  Hammers are cold pressed as standard on all Ronsen hammers.  This is to maximize tension.
    3.  The  felt sheets are skived to the final dimension prior to pressing so that minimal filing is done to the hammer after it comes out of the press.  This is very important because the tensioned areas of the felt on the outside of the hammers need to be maintained and not removed.  Hammers transition from tension in the outer layers to compression in the inner layers.  Heavy filing can remove the tensioned outer areas of the hammer and reduce the overall tension in the hammers.  Moreover, keeping the felt thin to begin with allows for maximum stretching of the felt which produces a more tensioned hammer and density that is achieved by stretching rather than pressing.  This creates a hammer with more bounce, greater resilience, better resistance to hysteresis effect and greater stability in tone.
    4.  These hammers are designed to closely match in profile the original dimensions of the 1920's Steinway hammers.  The original Steinway hammer was actually a lower density felt to begin with yet developed very nicely with plenty of power and brightness without chemicals.  The sheet density on this current iteration is somewhat greater.  Play in time is minimal if necessary at all.  The top few notes may require some hardening depending but typically I am not advising that any hardeners are used and so far I have not found it necessary.
    5.  This hammer is best suited for low to medium impedance systems.  High impedance systems such as concert instruments, certain Bosendorfer, Bechstein models (for example) may require something with slightly more weight and density.  Work in this area is in process.

    6. Profile dimensions should follow these specific guidelines (profile refers to the thickness of the felt above the underfelt):

    #1          12mm

    #26         9 mm 

    #40         7 mm

    #55         5 mm

    #70         4 mm

    #88         3 mm

     

    7 Light maple molding is used.

    8.  With light tapering and tailing the hammers are able to easily achieve the following weight.  More weight can be taken if needed by more full tapering and adding weight is easy using lead solder techniques.  I suggest that the tapering not extend all the way to the strikepoint of the hammer to protect felt at the strike point from being disturbed.  #88 may benefit from even more reduction in weight. 

    #1:         9.5 grams,

    #21:       8.1 grams,

    #40:       7.2 grams,

    #64:       6.0 grams

    #72:       5.2 grams,

    #88:       3.5 grams.


    9.  A like to do a fine polishing of the upper register hammers is recommended (above about note 55 or 60, though you can do the entire set as well).  I do this to about 1000 grit.  It is important to maintain the original shape of the hammer.  Cutting through layers of felt can reduce overall hammer tension.  While some play in can benefit the upper end, it can be measured in hours not years.  

    10.  Needle work should be minimal.  Low shoulder needling is not necessary at all.  Hammers that are too loud will respond from minimal needling (full penetration) in the 10:30 - 11:30 area.  I have my own needle techniques which I can elaborate on if necessary.  Less is more. 

    I continue to work with Ray to get a hammer that will work without lacquer for high impedance systems and concert situations where power is the first priority.  This particular iteration is designed to produce a wide range of dynamics.  I also will be trying some slight variations in this particular theme with respect to underfelt and sheet shaping and pressing.  But so far this particular hammer is working very well and I have put them on many pianos now starting at the end of last year. 



    (note: I will send the attachments that I mentioned of the hammer comparisons separately as the system is simply too unwieldy to do this easily  I will also cross post this under a new subject heading the "Weikert Low Profile Hammer "




    -------------------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    -------------------------------------------



  • 2.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 07-27-2013 13:39


    Resent with attachment




  • 3.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 07-27-2013 13:58


    -------------------------------------------
    William Truitt
    Bridgewater NH
    603-744-2277
    -------------------------------------------


    I spoke with Ray Negron yesterday about the hammers he is making for you, and he indeed confirmed that he could supply this style of hammer to me and others.  I am ordering it with underfelt to 88.  He recommended a 14 lb. hammer.  Is that in line with what he has been sending you?  This is for a Steinway M from the 20's with an original but healthy board. 

    Are you doing any pre-filing or filing with these hammers?  How much is needed to get them in the ballpark?

    Thanks for your continued efforts.

    Will Truitt







  • 4.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 07-27-2013 14:59
    The 14lb designation is sort of irrelevant. The final dimension of the felt is what matters. The difference between 16lb and 14lb is no longer an issue of density, as it once was, but dimension. I don't specify but presume that ray wants to do less skiving than more and so starts with the appropriately sized sheet. I get the hammers at the dimension I want so do not pre file other than to polish and square the strike point if needed. Or to refine the target profile. The goal is to get the hammers at the correct dimension and do as little as possible to alter them. ------------------------------------------- David Love RPT www.davidlovepianos.com davidlovepianos@comcast.net 415 407 8320 -------------------------------------------


  • 5.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 07-27-2013 15:34
    BTW, the order dimensions I posted are quite specific and I really do want to get them to that target.  However, the 3 mm target at note 88 often gets reduced to about 2 mm.  The underfelt on these sets does currently go all the way to 88 so there's more material over the molding than my final 2 mm.  But manufacturing at 2 mm is difficult so if it comes with a bit more up there I don't worry too much and just reduce it.  However, I really don't want to have to take much material off lower down in the scale (though I will if necessary) and Ray has been very good at hitting my targets very precisely.  It's more work for him and I don't know if that will ultimately be reflected in the price but it's an important part of this. 

    As I mentioned, and this is important, it's not the same to simply file a much larger hammer to these dimensions after they are pressed.  The ability to stretch the felt in order to acheive density as well as to preserve the tension in the outer layers of felt, I believe, is very important.  Having had hammers produced at these dimensions and having filed a standard 14lb set (and a 16lb one as well) to this final dimension I can tell you there is a difference.  A small amount of profiling is fine, but if you need to take away 1/3 or more of the material you'll will end up with something different.  I'm not saying it will be bad, just different and in my view not as good. 

    Among other things, and in keeping with the original subject line, the goal here is to avoid lacquer so that you have a hammer that is felt, all felt and nothing but the felt.  That impacts the longevity, stability and overall resilience and flexible quality that makes for a quality hammer.  Avoiding heat pressing and heat prepressing will maximize the tension in the hammer and help with that as well.  A heat pressed hammer, in my view, will require a different type of profiling.  The compromise in flexibility combined with greater overall density and lack of reslience (by that I mean the ability for the hammer to act like a more perfect spring) calls for a higher profile (thicker felt).  While all those things have their downside, it's the proper profiling working with the density and tension that will give the hammer the best chance to perform more optimally. 

    The class I've developed, and continue to refine, which is now called "Structural Voicing" addresses this and other issues related to tone production, goals, hammer design and execution issues and functions as an important prequalifier and differentiated from "procedural voicing" which is how voicing is typically taught--stick the needle here, do this, do that.  Procedural requirements will change depending on various factors, including the belly characteristics, of course.  We know that from the extreme differences of voicing with needles rather than lacquer.  But there are differences within those two camps as well.  Hopefully I'll have the opportunity to present it soon.  An article is forthcoming but taking a bit longer than I had anticipated to complete.  I had hoped to intruduce the Low Profile Hammer, along with that article but this discussion made it timely to do it now. 


    -------------------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    -------------------------------------------








  • 6.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 07-27-2013 17:40


    -------------------------------------------
    William Truitt
    Bridgewater NH
    603-744-2277
    -------------------------------------------
    The price he quoted me is pretty close to what we are paying from other top end hammer suppliers.  I'm getting mine unbored and overlong, as I do all my boring, tail length, coving, curving, tapering etc.  In the past when I ordered from Ronsen, I have requested underfelt to 88.

    I am looking forward to this set of hammers, it's a total new everything action rebuild with dampers for a teacher, so I will have to limit the downtime and complete it fairly quickly.  I will share my impressions of the hammer as the job progresses.

    I will be eager for your class.

    Will








  • 7.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 07-27-2013 17:31


    -------------------------------------------
    William Truitt
    Bridgewater NH
    603-744-2277
    -------------------------------------------
    Got it, thanks.  And Ray seems to have a pretty good idea what you want, and is willing to provide it to me.  I've been taking some of my hammers up to 1200 grit, mostly in the bass and tenor.  I'll try it in the treble on this coming set.

    Will







  • 8.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 07-27-2013 15:16
    David,
    This looks very promising. Thank you for your efforts.

    -------------------------------------------
    Fred Sturm
    University of New Mexico
    fssturm@unm.edu
    http://fredsturm.net
    "When I smell a flower, I don't think about how it was cultivated. I like to listen to music the same way." -Federico Mompou
    -------------------------------------------








  • 9.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 07-28-2013 22:37

    Please note the following correction.  The hammer should be officially referred to as the "Ronsen Weickert Special Low Profile Hammer".  This is both to correct the misspelling of "Weickert" in the previous subject line post and also to differentiate the Weickert Special Felt from other felt that is manufactured at the Wurzen factory which include: Piano, Grand A, Grand AA and Weickert Special. 

    While it may be possible to make any of the hammers in the "Low Profile" style, this particular one is done with the Weickert Special felt.  I'll be interested in feedback from those who try this.  Ray is set up to produce this hammer upon request. 

    Thanks.





  • 10.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 07-28-2013 23:25
    Thanks for writing about this, David. I plan to order a set from Ray tomorrow.

    -------------------------------------------
    Susan Kline
    Philomath, Oregon



  • 11.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 07-30-2013 01:50
      |   view attached
    Attached is a document with data from a freshly opened set of Ronsen Weickert "16 lb" hammers. These are not the Low Profile hammers. I put a set of these on a Young Chang G-200 recently and was pleased with the results. They did get a thin lacquer solution applied to the crown. The piano is now in a medium-sized church sanctuary.

    I am definitely interested in the Low Profile hammers. Thanks David for pursuing the holy grail - right-out-of-the-box, no hardener, no needling, zero-play-in-time, full color, vibrant and inspiring hammers.

    -------------------------------------------
    Alan McCoy
    Spokane WA
    ahm2352@gmail.com
    -------------------------------------------






    Attachment(s)



  • 12.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 07-31-2013 07:24

    Hi Alan,

    FYI I made a graph of your Hammer Wt data to rate them with my Hammer Weight Zones: 

    #1:         9.5 grams, 1/2 Medium

    #21:       8.1 grams, 1/2 Medium

    #40:       7.2 grams, 1/4 Medium

    #64:       6.0 grams 1/4 Medium

    #72:       5.2 grams, 1/2 Medium

    #88:       3.5 grams.  1/2 Medium

    Ref: http://www.stanwoodpiano.com/SW-HWstandards4.pdf

    David Stanwood



  • 13.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 07-31-2013 14:28
    Thanks David for going the extra step and comparing it to your chart. This set is going on a Yamaha C3 after having a good experience putting them on a Young Chang G-200. We'll see what happens.

    BTW, I just got off the phone with Ray to find out just what the difference is between "16 lb" felt and "14 lb" felt. He said they are the same density but they (the 14 lb hammers) are smaller dimensionally in the direction of David Love's Low Profile hammers.

    In comparing David Love's dimensions with the 16 lb hammers it was interesting to see that the #1 hammers were identical at 12 mm, and at hammer #88 the dimensions were close at 4 mm vs 3 mm. But DL's specs call for a much lower profile for all the hammers in between, kind of like you would see in a set of hammers that had been reshaped a few times reflecting little wear at the extremes. As people order and use these on Steinways and pianos with similar boards, it will be interesting to get feedback.

    The other comment from Ray that was interesting was that the Weickert felt is harder to cut and to sand. As well he is getting feedback from university techs and others in high-use situations that the Weickert felt is durable and shows less wear than previous hammers in the same venues.

    -------------------------------------------
    Alan McCoy
    Spokane WA
    ahm2352@gmail.com
    -------------------------------------------








  • 14.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 08-01-2013 08:16
    There are several points to make. The 16lb hammers that I have measured have all been much higher profile than mentioned. The set that came off a piano that I replaced with the LP hammer was more like 15 mm at note one and 6 mm at note 88. In between they were much larger. In general the hammers I have gotten in the past have varied in terms of profile and this created a significant variation in tone out of the box. In reality my preference is for 2 mm at 88 but to ask to have them manufactured that way is not reasonable. I do a light filing at the top. With respect to the Stanwood zones, those weights I posted were simply the result of uniform tapering of the set, though it's interesting to observe that this targeted profile seemed to closely match one of the zones. My own approach to the zones is a bit different than DS and I have developed my own zones that I tend to use. They differ somewhat from DS zones. First I use only three basic zones. The curve is somewhat flatter than the Stanwood zones and differences between zones is manifested most at the bass end and progressively less as you go through the set. The weight at note 88 is virtually the same for each zone. That's a function of tone rather than touch. Additional weight at the top end of the piano is usually of little or no benefit tonally and that is especially true at 88. The outer zones on the DS chart are simply something that under ordinary circumstances I would never use. Either the bass weight would be functionally too light or the treble functionally too heavy. This is in terms of tone production, which is how I prioritize weight selection. I then modify action ratios and touch weight to accommodate. Always in that order. This is a longer discussion to be thorough and for another time. I'll post my own zones when I can. The important part of this is while the weight in each zone may vary it does not do so by virtue of more felt or a higher profile. The profile of the hammer must work in concert with the overall density of the felt and the pressing and therefore remains the same no matter what zone you end up in. There's no reason, in my view, for the 14 or 16 lb designation because those are mostly dimensional references. Adding more weight by virtue of raising the profile would be especially detrimental in the treble section where the increased mass along with a more compliant hammer would effectively increase hammer string contact time to the detriment of tonal development. Overall that would also make the piano darker impacting upper partials throughout the piano. You'll be adding lacquer, something I like to minimize or, better, avoid entirely. Btw, the profile issue is important with heat pressed hammers as well though in that case, because of the altered nature of the felt, the profile (and to some degree the weight zone) would need to be much higher. If you want something uncontrollably bright try one of the hard, heat pressed hammers in the "lite" version. As for underfelt, these particular sets do currently have underfelt through the set. Noting that, I do have a set on order without underfelt at the upper end. The overall profile will change slightly where the underfelt disappears but I want to see if that doesn't make the top a bit brighter. I can't comment on the historic use of under felt and the reasoning except to say that it has not always been used and some makers don't, or haven't used it: Ari Isaac comes to mind and, for example, Bechstein makes a vintage hammer with no underfelt. I also have a different set on order which I'm testing for more high impedance pianos. I'll advise when I have more data. ------------------------------------------- David Love RPT www.davidlovepianos.com davidlovepianos@comcast.net 415 407 8320 -------------------------------------------


  • 15.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 08-02-2013 12:20
    Hi David,

    I'm so glad to get your views on the subject of hammer weight.    I think there is some confusion about the intended meaning and use of my published hammer weight zones. The three zones that I came up with  (low medium, and high) are the result of thousands of hammer weight studies made over the course of many years.   They represent what is expected to be found in pianos from 1880 to 2000.   There are 13 curve standards spanning the "normal" range.   There is no judgement about what is right or wrong.  They are simply codified observations.   In my view a big benefit of publishing and using these zones and curve standards is to create the ability for us to talk intelligently about hammer weights using a frame of reference that is available to all.     If someone says "I have a hammer weight of 7.8 grams for note 40 it's easier to conceptually think of that it is rated as a 1/2 medium hammer wt.   I am not advocating that we should all be using any one of the 13 curve standards as hammer weight specifications although they may be used that way by personal choice.    I often create hammer weight specifications that cut across the curve standards.  For instance, NY Steinway's frequently are found to start out in the low medium zone cutting across to the low high zone in the low capo area then down top medium in the high treble.  What I just described can translated into real numbers using the table.  There is no other published frame of reference for hammer wt.   It's what we have.    

    When you say "I have developed my own zones that I tend to use"  are you referring to an actual set of specified hammer or strike weights?   Send me your ideal hammer weight specification for these Low Profile Hammers and I'd be happy to provide a nice graph to share with the group and add to this important discussion.    

    Thanks David,

    David Stanwood

    Hammer Wt/ Strike Wt Curve Standards:  http://www.stanwoodpiano.com/SW-HWstandards4.pdf


    <snip>
    With respect to the Stanwood zones, those weights I posted were simply the result of uniform tapering of the set, though it's interesting to observe that this targeted profile seemed to closely match one of the zones. My own approach to the zones is a bit different than DS and I have developed my own zones that I tend to use. They differ somewhat from DS zones. 
    <snip>


  • 16.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 08-03-2013 20:51
      |   view attached
    I think many people take the zones as a strict guideline and follow them trying to remain within a single zone.  Whether that's what you intended or not is another matter.  That's how the charts are used by many, if not most.

    I sometimes take the set as it comes without doing huge alterations in order to just hit a zone.  But the Steinway example you mention illustrates one of the problems that can occur.  I generally have found the upper end of Steinway sets to be far too heavy (and bulky) for the production of clear tone through the treble especially.  Both excess mass and too high a profile in conjunction with soft Bacon style felt leads to excess lacquering (especially in concert grand sets), a hammer that loses resilience and simply doesn't produce the kind of tone that I prefer.  It's one of the reasons I don't prefer the Steinway hammer for their concert instruments especially.  The felt is simply too soft and too bulky and a poor impedance match for that scale and soundboard.  It is a classic case of felt density not working in concert with the profile.  For the treble, increased mass combined with soft felt and high profile is a sure recipy for lacquer and a lot of it.  I don't care for what it produces nor the voicing instability and development that comes with it.  But that is my opinion and others are free to disagree.  Obviously we work with what we have and technicians should generally be applauded for making the best out a less than optimal situation.  That includes both hammers that are too soft and bulky as well as those that are too hard and trim.  But I digress. 

    With respect to zones, I think that there is little reason that note 88 should vary much in weight whether the piano is a Concert Grand or a Small grand.  There will be more noise, more thump, more wood, more something, but the tone produced by the vibrating string will be lessened, if not lost, in the chaos and noise.  The bass end of the piano, on the other hand, can and does benefit from more mass which will produce a stronger fundamental (all things being equal) and I think something certainly better than a very light hammer will (especially a harder and lighter one).  That light hard hammer will produce far too many upper partials along with a weakened fundamental.  It simply won't sound good in the low end of the piano. 

    Thus, I think the zone chart, if it is to be followed, should have a somewhat different shape and the variations at either end should reflect that tonal goals.  If those who look at those charts are inclined to follow them I would say that the lower zones are too light in the bass and the higher zones are too heavy in the treble.  Zone crossing, then, might well be appropriate.  As I mentioned, touchweight issues are secondary to me.  Not that they aren't important, of course they are and I spend a lot of time and energy getting that part right as well.  But I like to start with tonal considerations and then set up action ratios and touchweight dynamics that will work best with the mass that is best for tone production.  Therefore, I tried to create a zone chart that made sense (to me anyway) in terms of tone production. 

    I've attached my two zone charts, one is based on a second degree polynomial curve (something like yours) the other is linear.  The top zone (zone 4) is something I would probably not use under most circumstances as it will begin to make touchweight problems in the bass that will differentiate the bass from the rest of the piano too much.  But it's there anyway.  Of course some modifictions can be made to the action to accommodate either by shifting ratios through the scale or assist springs, but since most of the inertia in the piano comes from the relationship between the hammer weight and the hammer shank ratio I don't like there to be too wide a spread between treble and bass.  So the first three zones represent my usual targets.  The low end zone represents the lightest weight I prefer in the bass to produce a full bass quality and the relative parity of the three zones with respect to the weight at note 88 represents my attitude about any excess mass in the upper end no matter what the piano is.  There are always exceptions of course but usually these are outliers.   

    The difference between the 2nd degree polynomial and the linear curves will then be mostly the degree of spread between them as you ascend through the scale.  I find a good tonal argument can be made to noarrow the difference as you go higher in the scale for reasons mentioned.  

    In actual practice I sometimes try and hit a specific zone exactly spot on but mostly I simply try and be in the ballpark.  That means within a few tenths of a gram.  A 1 gram variation from my target zone would be too much.  Vintage Steinway hammer sets typically come in lower than zone one.  For these smaller instruments I try and hit somewhere around zone one or between zone one and two.  That choice comes down somewhat to the impedance characteristics of the piano and a judgement call ultimately.  For very low impedance pianos (old soundboards in particular) I do try and stay on the lighter side of things.  The piano sounds better (to me) and the mass is not needed to produce power as the low impedance quality of those boards will tend to already lean toward the percussive side.  Less mass and a more resilient hammer (not mushy, thus the low profile hammer) will find a very good balance between ameliorating the attack and enhancing the sense of sustain.  Generally speaking, as soundboards age there is little reason to put on a hammer that produces more energy either by virtue of more mass or more density (thus less filtering).  The reactivity of the lower impedance soundboard simply doesn't call for it. 

    Higher impedance pianos will require some greater amount of mass in the bass, especially, and through the midrange. But as you ascend through the scale the need for more mass decreases.  Thus the higher zones in my chart will be a better fit there.  A somewhat firmer felt, or firmer pressing here will be beneficial, as we know, but that doesn't mean we need a 100 stitch hammer to bring out the power.  A coordination between the density of felt and the profiling can produce a hammer that is powerful enough without pressing the hammer into a ball pein variety that you can drive nails with.

    See attachments and forgive any typos, not enough time to proof this.   

    -------------------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    -------------------------------------------






    Attachment(s)

    pdf
    Strike Weight Zones.pdf   447K 1 version


  • 17.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 08-06-2013 09:53
    Hi David,

    I'm looking forward to responding to you.  Thanks for the hammer Wt Specifications info.  I'm up to my ears in the Summer Crush here on Martha's Vineyard and the PRez hasn't even arrived yet!   

    David Stanwood

    Original Message:
    Sent: 08-03-2013 20:51
    From: David Love
    Subject: Ronsen Low Profile Hammer

    <snip>

    I've attached my two zone charts, one is based on a second degree polynomial curve (something like yours) the other is linear.  The top zone (zone 4) is something I would probably not use under most circumstances as it will begin to make touchweight problems in the bass that will differentiate the bass from the rest of the piano too much.  But it's there anyway.  Of course some modifictions can be made to the action to accommodate either by shifting ratios through the scale or assist springs, but since most of the inertia in the piano comes from the relationship between the hammer weight and the hammer shank ratio I don't like there to be too wide a spread between treble and bass.  So the first three zones represent my usual targets.  The low end zone represents the lightest weight I prefer in the bass to produce a <snip>


  • 18.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 08-07-2013 14:49
    A few people have expressed some confusion on the two strike weight zone curves that I posted earlier in an attachment in this thread: one a 2nd degree polynomial and the other a straight line curve.  The two styles were derived from measurements that I have been taking (mostly Steinway pianos) compared with more recent trends on hammer sets (and pianos generally).   Many of the older Steinways that I have measured show a more straight line strike weight curve with the mid range hammers being relatively lower than their curved counterpart.  For example, on a 1930's steinway that I am currently redoing, the hammer weight at note 40 is about 6 grams while the hammer weight at note 1 is about 9 grams.  Note 88 on that set is something under 3 grams.  This is much more of a straight line: y =mx + b).   The second degree polynomial equation would look more like y = x^2 + x + c and depending on the actual equation would push up the weight in the mid range.

    By plotting the actual weights of the hammers on an excel spreadsheet you can produce a graph and from insert a trendline (pick the type that matches it best) and excel does a fine job of showing you the equation for that trendline.  From that you can derive your own strike weight curve as you see fit, either one that matches what you have there or one more to your liking. 

    As far as which model I use in actual practice, it depends on my particular goals and what the set delivers--I don't lose sleep over the exact shape of the curve.  There is some evidence that the trends of the past were a more straight line in order to keep the upper half of the piano on the lighter side.  A good argument can be made for that in terms of tone.  I find most stock sets to have both too much mass and questionable profiling in the upper half of the piano.  But that may simply be my own preference. 

    -------------------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    -------------------------------------------








  • 19.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 08-14-2013 08:34
      |   view attached
    David Love shared with us his StrikeWt/HammerWt curve standards in data form and I've formatted his data into curves that can be compared with my "Normal Zone" of SW/HW in Graph format in order to get a visual/right brain idea of what he likes.   David L tells me that SW1 is what he feels is ideal for the Ronsen Low Profile Weickert Hammers.    The heavier SW/HW weight he'll use for concert halls or special cases.   Thanks David L for sharing your data!

    David Stanwood

    SW/HW zones Ref to: http://www.stanwoodpiano.com/SW-HWstandards4.pdf

    Attachment(s)

    pdf
    SWHW-DL-2013-08.pdf   638K 1 version


  • 20.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 08-14-2013 16:13

    I posted these comments (below) and qualifiers to David Stanwood re his interest in overlaying the Strike Weight Curves over his.  It's not so much that SW1 is ideal for the hammer of the subject line, but please read:


    SW4 is included for theoretical purposes but in practice I would never likely use it.  In fact, I would say 90% or more of what I do falls between SW1 and SW2 but there are exceptions, of course.  For example, if I'm trying to match an existing set of hammers rather than, say, replacing an action entirely where I have leeway in terms of controlling action leverages, or if I have a belly that calls for something different.  My choosing hammers always takes into consideration four basic qualities: tension (maximized), mass, density, profile.  Felt quality felt is a given. 

     

    The "Ronsen Low Profile Weickert Special Hammer" (which is how it is officially referred to) with normal tapering generally falls close to SW1 and that is my preference for most pianos.  As I mentioned earlier, I don't necessarily try to hit the curve exactly.  It's a guideline and I will allow some deviation depending on what the set gives me.  However, the deviation, if any, is generally pretty small, certainly under .5 grams. 

     

    SW2 (or possibly SW3) would be a consideration for performance pianos or higher impedance instruments where additional mass in the bass and into the midrange can provide a power benefit.  Added mass becomes less important, and at a certain point detrimental, the higher you go in the scale (thus the notably smaller deviation between the zones at note 88 than at note 1).  In those cases, other basic qualities that I mentioned will likely change as well.  Density will usually ratchet up and along with it the overall profile of the hammer.  But the differences I seek are relatively small compared to what I see out there.  In the "Structural Voicing" class I give, btw, this is all discussed.

     

    David Love



    -------------------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    -------------------------------------------








  • 21.  RE:Ronsen Low Profile Hammer

    Posted 07-31-2013 09:59
    Wonderful David. These might be just what I've been looking for to replace hammers on a 4'11" Chickering.

    I'm sure others in this discussion group have had much more experience with many, many more sets of original old style
    Steinway hammers from the early days than I have, so the discussion is very helpful.

    Some hammer makers have said in the past that the under felt is just cosmetic.

    So why did Steinway and other mfg. use under felt if it was not for tone?

    Thanks for posting this David. I know you might think it premature to do so, but it really helps.

    Cheers,
    Richard Adkins


    -------------------------------------------
    Richard Adkins
    Piano Technician
    Coe College
    Cedar Rapids IA
    -------------------------------------------








  • 22.  RE:Ronsen Low Profile Hammer

    Registered Piano Technician
    Posted 08-15-2013 13:25
    The colder the felt, the more it resists bending. The underfelt essentially makes the tip of the core more rounded to the hammer felt. This reduces the curling of the felt toward the tip of the core in cold- and wam-pressed hammers. The curling, as I understand, is mostly a cosmetic problem, but can compromise the strength of the glue joint.

    -------------------------------------------
    Mario Igrec
    http://www.pianosinsideout.com
    -------------------------------------------

    -------------------------------------------
    Original Message:
    Sent: 07-31-2013 09:58
    From: Richard Adkins
    Subject: Ronsen Low Profile Hammer

    Wonderful David. These might be just what I've been looking for to replace hammers on a 4'11" Chickering.

    I'm sure others in this discussion group have had much more experience with many, many more sets of original old style
    Steinway hammers from the early days than I have, so the discussion is very helpful.

    Some hammer makers have said in the past that the under felt is just cosmetic.

    So why did Steinway and other mfg. use under felt if it was not for tone?

    Thanks for posting this David. I know you might think it premature to do so, but it really helps.

    Cheers,
    Richard Adkins


    -------------------------------------------
    Richard Adkins
    Piano Technician
    Coe College
    Cedar Rapids IA
    -------------------------------------------


  • 23.  Ronsen Low Profile Hammer

    Posted 07-31-2013 10:16
    On 7/31/2013 8:58 AM, Richard Adkins wrote: > > So why did Steinway and other mfg. use under felt if it was not for > tone? I'm certainly no expert on hammers or felt, but from a mechanical standpoint it's easier to force two layers of dense felt totaling X depth into a tight bend than it is one layer of the same total thickness. With hot presses, it would be less a problem, but with cold pressing, it looks to me that it could be more difficult and touchy. Like bending wood into tight curves requires either lamination or steam. Anyone have some real information on that, rather than my uninformed opinion? Ron N