<!doctype html public "-//W3C//DTD W3 HTML//EN"> <html><head><style type="text/css"></style><title>Re: bobbling hammers, again</title></head><body> <blockquote type="cite" cite><font face="Arial" size="-1">Several months I asked about bobbling hammers in a grand. I discovered that the shank lenght was too long.<br> <br> I now have a similar problem with a D. But this time, I've rebuilt the action with new Steinway parts, (new h,s,f and wipps). There are three notes that are driving me nuts. Unless I really smack the note, the hammer doesn't want to check. They boble so bad that they hit the string on the rebound.<br> <br> The regulation is just like the other notes, (dip, l.o.,drop, etc.). Not only is key dip just like its neighbors, but when I increased key dip, it didn't solve the problem. There is enough damper lever clearance. I've adjusted the back checks to where the hammer checks almost back down on the cushion. When I try to make it check earlier, it catches. I've bent the checks so that the rake is enough to clear the hammer on the way up, but still catches it on the way down. I've reduced spring tension to the point of almost no rise, and I've sanded the backs of the tails. I even changed wippens on one key, but the problem is still there.<br> <br> What are some other things I should look at?<br> <br> Wim</font></blockquote> <div><br></div> <div>Check that the capstan line is straight. An out-of-line capstan can cause the hammer/key ratio to be too low if the capstan is positioned towards the key balance pin. This could result in insufficient clearance between the roller and jack when in the check position, which can cause unreliable checking. Similarly, an out-of-line roller (if it is positioned further out towards the hammer head) will affect the ratio also. The jack should ideally just clear the roller when the action is in check. If it clears by too much it will have a deleterious effect on repetition speed. If it is contacting the roller it may cause the checking to be unreliable.</div> <div><br></div> <div>Another outside possibility is an out of position balance pin hole, which may similarly effect the leverage ratio. I've seen some pretty ordinary balance pin hole alignment, even in Kluge keyboards in recent years, so this problem can occur even with some of the most reputable keyboard makers.</div> <div><br></div> <div>Ron O.</div> <x-sigsep><pre>-- </pre></x-sigsep> <div><font face="Times New Roman" size="+1" color="#0000FF"><b>OVERS PIANOS - SYDNEY</b></font></div> <div><font color="#000000"><i>   </i></font><font color="#0000FF"><i>Grand Piano Manufacturers</i></font><font color="#000000"><br> _______________________</font></div> <div><font size="-2" color="#000000"><br> </font><font color="#000000">Web http://overspianos.com.au</font></div> <div><font color="#000000">mailto:info@overspianos.com.au<br> _______________________</font></div> </body> </html>