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.
------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------
Original Message:
Sent: 10-26-2019 21:20
From: Benjamin Sanchez
Subject: Steinway Wippen Replacement
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?
------------------------------
Benjamin Sanchez, RPT
Piano Technician / Artisan
(805) 315-8050
www.professional-piano-services.com
Original Message:
Sent: 10-26-2019 20:42
From: Sean Stafford
Subject: Steinway Wippen Replacement
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
------------------------------
Sean Stafford
Endicott NY
607-239-4643
------------------------------