<!doctype html public "-//w3c//dtd html 4.0 transitional//en"> <html>     Sounds like the hammer bore distance is too long. I've run into that on old Steinway uprights someone else rebuilt, at least a couple times. When the jack is all the way under the butt, there is lost motion. Take it up and the jack won't get back under when the parts return slowly. And, yes, extreme dip needed to avoid bobbling. Removing hammers and re-boring doesn't sound too inviting. I'm afraid I never did come up with a good solution. Thicker butt felt sounds like the best notion. Regards, Fred Sturm University of New Mexico ANRPiano@aol.com wrote: <blockquote TYPE=CITE>List, I need some help here, I am out of easy solutions. Problem:  Steinway uprights, 1 "K", 1 "X", and 1 "I", the first new, the latter two rebuilt by yours truly.  All have hammers the bobble.  I have rebuilt other Steinway uprights and serviced others of similar vintages which had no problems.  From the best I can tell the jacks start too far under the butt to clear the butt without extremes amount of dip.  In the "X", out of desperation, (I was at a customer's home, far from my home and didn't want to make another trip) I removed all of the butts from the center of the piano (double flanges), removed the jack rest felt and shimmed them out about 1/16". This was not a fun job!  Has anyone else seen this?  Any ideas as to a simpler solution? Thanks. Andrew Remillard ANRPiano.com ANR Piano Service 2417 Maple Ave Downers Grove, IL  60515 630-852-5058</blockquote> </html>