---------------------- multipart/alternative attachment Hi Tom, =20 Thanks for the reference. Excellent instructions. =20 Alan=20 =20 -----Original Message----- From: TOM DRISCOLL <tomtuner@verizon.net> To: Pianotech List <pianotech@ptg.org> Sent: Sat, 18 Feb 2006 11:33:49 -0500 Subject: Re: Vertical hammer return spring slings, replacement of =20 Hi All, =20 This Monday I will replace all of the hammer return spring slings on an olde= r Yamaha U3. Yamaha graciously provided the cord material. Someone advised= removing all of the dampers and leaving the hammers on for the operation. =20= However, looks to me like it would be rather tricky to get the glue and the=20= right length of cord in the right place in the hammer flange slots with the=20= hammers still on the rail. My current plan is to leave the dampers, but rem= ove all of the hammers so they may be handled individually. =20 Anybody out there worked through this to their satisfaction? Got a solvent=20= that works better than alcohol for loosening up the old glue? For installin= g the new cords, have you used CA, hide glue, what-have-you? =20 =20 Any and all input is welcome, all the more so if it is before Monday morning= . =20 Have a good weekend, =20 Alan Eder, RPT =20 Alan, This description from our friend Jon Page in=20 much more detail than my post from the archives of some years back. Jon has chosen to omitt the use of acetone as a glue solvent in his step= 9 but I find the acetone to virtually allow you to wipe the old cords from=20= the slots and have seen no deleterious effects on the flange bushings. JMHO= . Tom Driscoll =20 =20 Yamaha Hammer Spring Cord Repair=20 Problem:=20 Hammer return spring cords have become fragile and are breaking.=20 Symptoms:=20 Cords have turned a brownish color.=20 Random breakage is occuring.=20 Touchweight is affected on some notes where the spring is contacting the d= amper lever.=20 Hammer sometimes falls audibly into strings on slow release before being p= ulled back by bridle tape.=20 Solutions:=20 Replace hammer flanges=20 Replace cords=20 Condition of action:=20 If condition of the hammers, pinning, and travelling/mating to strings is=20= all good, replace cords.=20 If pinning is poor then flange replacement may be a better option.=20 Beware of earlier type action without butt plates - the following method w= ould not work in this case. Cord Replacement Procedure:=20 1. Place action in cradle; remove hammer rest rail and treble bracket.=20 2. Reverse action so that hammers and dampers are facing you.=20 3. Loosen hammer butt plate screws.=20 4. Remove hammer assemblies from flanges and let hang from bridle wires= ; keep them in order to avoid tangling.=20 5. Straighten any bent return springs.=20 6. Tighten all wippen flange screws.=20 7. Tilt action toward you 90=B0 so that the hammer flange cord slots fa= ce upward.=20 8. Tighten remaining flange screws. 9. Using specially adapted shimming chisel or other suitable tool, clea= n slots (no solvent) and vacuum up debris.=20 10. Wrap 90+ turns on dowel with new cord and cut turns with a razor.=20 11. Glue one end of each piece to one slot on each flange.=20 12. Return to first flange and glue the other ends to remaining slots; ch= eck with gauge.=20 13. Lubricate damper spring slots.=20 14. Replace hammers; tighten butt plate screws; hook springs under flange= cords as you go.=20 15. Replace hammer rest rail bracket and reinstall rest rail.=20 16. Final check: jack springs engaged with jacks, spring cords in crook o= f hammer return springs, bridal tapes not twisted.=20 Tools and Materials:=20 __flange, thin-bladed, and Phillips screwdrivers=20 __spray lube and spring hook (for damper springs)=20 __shimming chisel modified to clean flange slots, or other suitable tool __glue applicator (syringe) filled with Tightbond & damp rag=20 __action cradle=20 __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 car= dboard __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=20= check loop size)=20 __razor=20 __forceps=20 Many different types of cord will work. White braided Dacron looks the best=20= and will last forever. Joe Goss suggests Spider Wire which I've bought but h= aven'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 w= ell to Tightbond. Probably the easiest (and possibly cheapest) is to order t= he 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.=20 This method is taken from Tom Driscoll who posted it to the list in May, 200= 2 (Yamaha Upright Hammer Flanges).=20 =20 =20 ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/13/29/bd/0a/attachment.htm ---------------------- multipart/alternative attachment--
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