<HTML>In a message dated 3/13/02 10:19:20 PM Central Standard Time, poseyviolins@charter.net writes: <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">All the rollers on my hammers are flattened and/or grooved. Is this a serious problem?  Is there a fix besides replacement?  This is my own piano (Heintzman Baby Grand) that I'm working on as a hobby. Thanks, Gerald </BLOCKQUOTE> Gerald Flat rollers, (knuckles) give the piano an uneven feel, and it is harder to regulate the action with flat knuckles. You've gotten some good advice from several technicians. Rob Goodale and Richard Brenke recommended "yarning" the roller (knuckle). That is probably the easiest thing to do. But be sure to use real wool, however. The inside of the knuckle is wool.  Wool yarn will adhere to the wool in the core, and will not flatten out. If you use nylon, it will flatten out too much, and it might even creep out. To "yarn" the knuckles, remove all the hammers from the stack, and then, with the wool yarn on a large needles, push the needle between the leather outer cover and the wool core. You can all the the knuckles at once. When you have them all on the yarn, take a razor blade and cut the yarn. As Richard warned, be sure there is no yarn sticking out of the side of the knuckle. After you do this, you will need to regulate the action. At most, you will need to let down the hammer line, by adjusting the capstans. You will probably also need to adjust let off and drop. I am not sure how much you know about all these terms, or how much experience you have working on pianos, but you'll find out that solving one problem often creates other problems. Good luck Willem Blees RPT University of Alabama</HTML>