<html> <body> Wim - Don't give up!  As a last resort, you could schedule an event like what Mark Cramer did for Wapin, and invite everyone down.  But we're not there yet. I think the first thing you have to do is get off this thing about the rep lever pinning.  It's important, but not relating to checking.  As detailed and specific as Ed Foote's last reply was, there are still other subtleties which can make the difference, but they're hard (for me) to convey in this format.  The area you mention (F2 - F3) are angled hammers.  Determine if the facing is completely parallel to the back check.  I've seen plenty of examples of sloppiness here, which would reduce the contact area to one edge of the tail, especially with the new, firmer backchecks. Look CLOSELY, (or is it  closely?) at the initial contact of the tail and check.  The shape of the Steinway backcheck can deceive you as to the actual distance between the "functional" bottom of tail and top of check.  Look at the difference in some other tail-check configurations.  Notice the difference in the shape of the check felt and its resulting profile.  The older ones were more square at the top, effectively placing the functional surface of the check closer to the top. Gently press the hammer down to the check and observe the length of initial contact (ICL).  If the backcheck has any convex radius and the tail has a short-ish radius, the contact length will be insufficient.  The  Steinway tails I first became familiar with were not an exact radius.  More of an angled flat face of about 1/2" before gradually becoming parallel to the center line.  This allowed more surface contact than a radius but had enough angle to prevent slide-through on a strong blow. Some style backchecks achieve a more concave surface which tends to allow for a straighter tail and generally softer checking shock.  I don't believe you referred to the age of this piano.  I'd like to know if it has the older style of backchecks & wires or new.  The newer ones have very stiff wires and very firm felt/leather.  This tends to eliminate what I think is an important spring function. I apologize if the above is unclear.  Keep trying.  Think of the moment when you figure it out. David Skolnik At 05:48 PM 12/15/2006, you wrote: <blockquote type=cite class=cite cite="">Quoting David Skolnik <davidskolnik@optonline.net>: > Hey Wim - > Just a friendly reminder.  Have you had a chance to look at the piano > yet? > > David Skolnik > > > > At 08:58 AM 11/15/2006, you wrote: > >Since this thread got started with wippens, I want to report that I > am > >not going to be able to do the work on the balanciers on the D > until > >Dec. 7. I will give a report once I'm done. > > Today I got a chance to do some more work on the wippens in the D on our concert stage. First of all, instead of calling them bobbling hammers, I think it would be better described as non checking hammers. Bobbling hammers means there is something wrong. From what I am able to figure out, there is nothing wrong with a hammer not checking. I tried everything. My focus was on F2 - to F3, especially on F2- A2. These seemed to be the ones that were not checking, no matter how hard I hit the key. I checked the balancier of F2 and found it to be at 2  grams. This is what it was a few weeks ago when I had repinned from 2 grams to 6 grams. So I repinned it again, this time to 7 grams. But the hammer still did not check. I tried to play every note in this octave with the same amount of force. I found C3 to "non" check, but C#3 to check. So I measured the balancier on each one. Both were at 2 grams. I made sure everything else was the same. So why does one hammer at 2 grams check, and the other not? I don't know. I did get a little better checking when I pushed the checks back a little, which gave me about 3/4" - 7/8" checking distance. But other than that, I am perplexed. I don't know why these hammers are not checking. I tuned a 5'5" Young Chang the other day, and even on a fairly soft blow, all the hammers checked. As I wrote earlier, all of our regulating procedures can be  measured. But when it comes to having hammers checked, there are no measurements. The curve of the tail, the rake of the back check, the roughness of both the tail and the backcheck, the strength of the spring, and the amount of touch, all have an effect on how a hammer checks. But there is virtually no way of measuring these things. Nothing I have tried seems to work. So for now, I give up. But if anyone has another answer, I will be glad to try again.  Wim Willem Blees, RPT Piano Tuner/Technician School of Music University of Alabama Tuscaloosa, AL USA</blockquote></body> </html>