Pianotech

  • 1.  Steinway Wippen Replacement

    Posted 10-26-2019 20:42
    These pictures taken as I was replacing the wippens
    More photos
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    I replaced a set of wippens on a Steinway D  today and I have a little (big)  problem (opportunity ?) I wasn't expecting. Posting here for advice please.

    The client has a NY Steinway D cir 1950​ and he is a musically advanced player. He plays very well and by my humble estimation plays at a virtuoso level. 

    He plays Chopin Etudes, Scriabin, Rachmaninoff and Beethoven and his music pushes the performance envelopes of the piano. 

    He has always had a concern/complaint about double strikes on pianissimo passages. It's been intermittent and impossible for him to duplicate for me.  I regulated the action and he called me the next day very pleased with the evenness of touch and the responsiveness of the action but he still reported getting double strikes in pianissimo passages. He would attempt to play them for me, but we could not duplicate. It seemed to disappear when I'm around. 

    The wippens are original and he asked me to replace them.  I used the Renner kit to match the replacement wippen and today I installed the new set. 

    I'm not sure what the heck is going on but now since replacing the wippens I have significant double strikes and hammer bobbling but mostly in one octave F2 to F3 and for the life of me I cannot figure out why?  

    I've set hammer blow, aligned jacks, adjusted backchecks, set letoff.... it should work! But it doesn't, granted it plays, but there is significant bobbling. 

    The most significant thing I think I can add is that when I changed wippens I needed to reduce capstan height to acheive the same hammer height and blow distance.  So there's something to that. I wish I knew why. 

    That' really the first thing in this project that I couldn't understand. The wippen matched exactly the old wippen minus the hammer rest cushion. That was slightly different, but the hammers don't rest on that anyway.  I couldn't understand why the new wippens changed the hammer height (blow distance) and required me to adjust the capstan to achieve the original blow distance. 

    But I don't think that would cause this problem..... I adjusted the capstan, I have good blow distance (1 7/8) and I think I should be good to go. 

    The double striking hammers (on pianissmo) all seem to want to bobble as if the knuckle is landing on the jack but I can't see how that is happening!

    Do I sound confused??  It would help me greatly if the list could weigh in and share their thoughts. I have to go back to this piano tomorrow afternoon and I'd love to come back armed with new ideas. 

    Thanks everyone :)

    Sean 



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    Sean Stafford
    Endicott NY
    607-239-4643
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  • 2.  RE: Steinway Wippen Replacement

    Registered Piano Technician
    Posted 10-26-2019 21:21
    Hi Sean,

    I have a very strong suspicion that your problem is related to the repetition lever. Either your springs are too strong (which is my initial suspicion), or the pinning is off (which is also a possibility). I assume you know how to regulate spring strength, and will be able to check that fairly easily. If it's the pinning of the rep lever, you'll need to pull the wippen, disconnect the spring, and measure the resistance. Specs should be about 6-8 grams.

    Also, if it’s only happening in one octave or so, it’s possible your balance rail glide bolt is off. Re-bedding the keyframe may solve your issue. 

    I'd also recommend calling Rick Baldassin, who is Renner's technical field support. His info's in the directory.

    Edit:

    I just saw your comment about changing capstan height to achieve the same hammer line. Is it possible that your replacement wippens have a different heel than the originals? Because that would really mess with and change the action ratio, and it’s possible that that would cause the problems you’re experiencing. Do you still have the originals, and could you measure?

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    Benjamin Sanchez, RPT
    Piano Technician / Artisan
    (805) 315-8050
    www.professional-piano-services.com
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  • 3.  RE: Steinway Wippen Replacement

    Posted 10-26-2019 21:57
    Its not checking consistently. You did not mention checking in your post (I don't think).  Sounds like the checking is challenged. This will happen if you tightened up the regulation specs, get a real good feel, but neglect to deal with aged, worn back checks, or without making sure the check height and angle are appropriate for that particular action. Since Steinway string heights are all over the map from the factory, their checking heights can be all over the map too.

    Widen up letoff if its too tight. This will allow you to lower drop. Lowering drop effectively takes the rep lever spring out of the picture a little, which is the cause of the bobble.  That last sentence is the quick and dirty solution. Getting check to work well requires everything be right on the nose. It does not sound like your rebuilding chops allow you to know what right on the nose is yet, so the  quick way out, is to lower letoff and drop a bit.

    More time consuming would be to learn how to find what height for the check head and what checking height is appropriate for that " as built action". The 5/8" automatic check height folks teach will leave you scratching you head, wondering why you can't get it to check. Your question is a big and tough question, but doable with much thought and experimentation. That's why I offered the quick and dirty up above.  It took me quite some time and much thought to understand the relationship between excellent pp checking, and tail/check geometry. Everything has to be right for it to work...and then sometimes it still is frustratingly inconsistent. Lightening up hammers, widening letoff, and lowering drop to fit that new lower letoff will get you some way there on this job. 

    On older, out of regulation pianos checking will mostly be pretty good before you work on the action. That's because, in the out of regulation action, drop is usually so low, like 1/2", that the rep spring is taken completely out of the picture, and the rep spring is what is forcing the tail out of questionable check and causing the the bobble, or double strike.

    ALso, if the checking is already okay, drop may be too high. Make sure your letoff and drop are not set at super close specs. If letoff is very close, and you raise drop to achieve synchronicity, you will often have the hammer blocking...but I think its the checking. 

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    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
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  • 4.  RE: Steinway Wippen Replacement

    Posted 10-27-2019 13:05
    When key is all way down, does jack has free play ?

    Alexander Brusilovsky




  • 5.  RE: Steinway Wippen Replacement

    Registered Piano Technician
    Posted 10-26-2019 22:00
    Sean

    I had that problem with a D at the university I used to work for. Check the rake of the backcheck to the hammer tail. And also the roughness of the tail. After many years of playing the tail smooths out and will not catch on the backcheck. It doesn't take much to "rough" it up. Use 220 or even 440 sandpaper to sand the tail, with the grain.

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    Willem "Wim" Blees, RPT
    Mililani, HI 96789
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  • 6.  RE: Steinway Wippen Replacement

    Posted 10-26-2019 22:05
    D's are notorious for out of spec string heights, which completely screws with the check geometry.

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    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
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  • 7.  RE: Steinway Wippen Replacement

    Posted 10-26-2019 22:18
    Adjust b/c angle to be ~72 ° to the key stick. hat is the radius of the tail arc? Check center friction on shank, rep. and rep lever. Fine tune rep. spring strength. Is the dip adequate. Does the jack clear the knuckle at full key stroke? Replace back checks or the suede for better grip. I think the new Renner parts are a slightly different geometry than the originals.

    Did the original reps have an angled heel and the new ones straight.

    Edit:
    I've taken a closer look at the photos. When the hammer is held in the 'drop' position, the b/c should be level with or 2 mm below the hammer tail.
    Are the tails 27 mm in length?  Action spread (I've read, according to RIck Baldessin) might best be at 112.75 mm.  Hammer at rest position (correct blow distance) the knuckle core should align (point to) with the jack center. Check action elevations. HCH, WCH, String Height, Hammer Bore. Don't forget the Magic Line.

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    Regards,

    Jon Page
    mailto:jonpage@pianocapecod.com
    http://www.pianocapecod.com
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  • 8.  RE: Steinway Wippen Replacement

    Registered Piano Technician
    Posted 10-27-2019 10:14
    You didn't mention aftertouch.  Did you check that and in what manner?  If you don't have adequate aftertouch then the jack will not clear properly from the knuckle and on pianissimo playing you're more likely to get bobbling.  Check aftertouch by inserting a .030" (minimum) or .045" punching over the existing front rail punchings (you can cut a slot in the  punching so you can just slip it in without raising the key.  With the punching inserted, when the key is lightly but fully depressed, you should just get escapement with no aftertouch.  Once the test punching is removed that is the amount of aftertouch you need.  Dip the keys using this method to insure adequate jack clearance. 

    Of course, you can also increase aftertouch by raising the hammer line.  With such variations in string height as are present in Steinways you really need to check the key dip/blow relationship in terms of adequate aftertouch.

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    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
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  • 9.  RE: Steinway Wippen Replacement

    Posted 10-27-2019 20:35
    Thanks to all of you for the replies to my question.

    I was able to finish the wippen installation and regulation today and it went well.  No bobbling hammers and good repetition. The problem was resolved by adjusting the repetition spring tension.   These wippens have a repetition adjustment screw and reducing the repetition spring tension did the trick for most notes.  

    In addition to that the checking needed to be adjusted on a few notes to completely stop the bobbling. 

    This list is a wonderful resource, I do try to work things out myself first but there is no substitute for the collective wisdom and experience I have found in the PTG discussion groups.  Thanks again to all of you. 

    Sean

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    Sean Stafford
    Endicott NY
    607-239-4643
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