Archives has a lot on this... Here are instructions. I got them from Tom Cole, RPT. He can do it = in around 2 hours, give or take. I'm sure his shop area is far more = efficiently organized than what I was using at the time. The first time = took me around 4, second time was about 3 hours. I see another one on = the horizon soon! Dave Stahl Problem: Hammer return spring cords are breaking due to unknown cause Symptoms: Cords have become a brownish color Random breakage is occuring Touchweight is affected on some notes; hammer sometimes falls into = strings on slow release Solutions: Replace hammer flanges Replace cords Condition of action: If condition of the hammers, pinning, and travelling/mating to strings = all good, replace cords. If pinning is poor then flange replacement may be a better option. Cord Replacement Procedure: 1. Place action in action cradle 2. Remove hammer rest rail and treble bracket 3. Loosen hammer butt plate screws 4. Remove hammer assemblies from flanges and let hang from bridle = wires 5. Straighten any bent return springs 6. Tighten all hammer/damper/wippen flange screws 7. Tilt action 90=B0 so that the hammer flange cord slots face up 8. Using specially adapted shimming chisel, clean slots and vacuum up = debris 9. Wrap 90+ turns on dowel with new cord and cut turns with razor 10. Glue one end of each piece to one slot on each flange 11. Return to the first flange and trim each cord to length 12. Glue other end to remaining slot; check with gauge 13. Replace hammers; tighten butt plate screws; hook springs under = flange cords as you go 14. Replace hammer rest rail bracket and reinstall rest rail 15. Final check; jack springs engaged with jacks, spring cords in hook = of hammer return springs, bridal tapes not twisted Tools and Materials: =AE flange screwdriver =AE thin screwdriver =AE Phillips screwdriver =AE shimming chisel modified to clean flange slots =AE glue applicator (syringe) filled with Tightbond =AE end nippers with gauge =AE action cradle =AE replacement cord (braided Dacron of suitable diameter) =AE 5/8" dowel [9/16"] =AE blunted scriber =AE gauge (dowel) =AE razor =AE forceps =AE damp rag David Ilvedson, RPT Pacifica, CA 94044 Original message From: KeyKat88 at aol.com To: pianotech at ptg.org Received: 3/22/2009 4:43:54 AM Subject: [pianotech] U3 hammer flange string / fiber Greetings, Is it possible to replace/glue the hammer flange spring thread using new (non-breakable) nylon thread instead of the thin (tear-able) fiber thread they originally used? Is replacing these a tough job? Thoughts? Thank You, Julia Gottshall Reading, PA Feeling the pinch at the grocery store? Make dinner for $10 or less. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech_ptg.org/attachments/20090322/82741f5e/attachment.html>
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