<html> <body> <div align="center">Yamaha Hammer Spring Cord Repair </div> Problem:   Hammer return spring cords have become fragile and are breaking. Symptoms:   Cords have turned a brownish color.   Random breakage is occuring.   Touchweight is affected on some notes where the spring is contacting the damper lever.   Hammer sometimes falls audibly into strings on slow release before being pulled back by bridle tape. Solutions:   Replace hammer flanges   Replace cords Condition of action:   If condition of the hammers, pinning, and travelling/mating to strings is all good, replace cords.   If pinning is poor then flange replacement may be a better option.   Beware of earlier type action without butt plates - the following method would not work in this case. Cord Replacement Procedure:   1.    Place action in cradle; remove hammer rest rail and treble bracket.   2.    Reverse action so that hammers and dampers are facing you.   3.    Loosen hammer butt plate screws.   4.    Remove hammer assemblies from flanges and let hang from bridle wires; keep them in order to avoid tangling.   5.    Straighten any bent return springs.   6.    Tighten all wippen flange screws.   7.    Tilt action toward you 90° so that the hammer flange cord slots face upward.   8.    Tighten remaining flange screws.   9.    Using specially adapted shimming chisel or other suitable tool, clean slots (no solvent) and vacuum up debris. 10.    Wrap 90+ turns on dowel with new cord and cut turns with a razor. 11.    Glue one end of each piece to one slot on each flange. 12.    Return to first flange and glue the other ends to remaining slots; check with gauge. 13.    Lubricate damper spring slots. 14.    Replace hammers; tighten butt plate screws; hook springs under flange cords as you go. 15.    Replace hammer rest rail bracket and reinstall rest rail. 16.    Final check: jack springs engaged with jacks, spring cords in crook of hammer return springs, bridal tapes not twisted. Tools and Materials:   __flange, thin-bladed, and Phillips screwdrivers   __spray lube and spring hook (for damper springs)   __shimming chisel modified to clean flange slots, or other suitable tool   __glue applicator (syringe) filled with Tightbond & damp rag   __action cradle   __replacement cord, e.g., braided Dacron of suitable diameter (kite string, parachute cord) or silk cord (Pianotek)   __9/16" dowel [turned down from 5/8" dowel] or suitable width piece of cardboard   __blunted scriber (or use small screwdriver, to help place cords in slots)   __gauge (dowel, sized to fit intact flange cord, with end rounded off, to check loop size)   __razor   __forceps Many different types of cord will work. White braided Dacron looks the best and will last forever. Joe Goss suggests Spider Wire which I've bought but haven't tried yet. It's a similar color to the stuff you're replacing so that tends to go against using it. I used to use squidding line but the kind you'll likely find in fishing supply places is waterproofed and wouldn't take well to Tightbond. Probably the easiest (and possibly cheapest) is to order the silk action cord from Pianotek ($3.95 for a 30-yard roll). Cleaning out the slots is not critical and you could even give the flanges a quickie scrub and vacuum treatment and commence with step 10. This method is taken from Tom Driscoll who posted it to the list in May, 2002 (Yamaha Upright Hammer Flanges). </body> </html>