Ric, I did the numbers again: R #1 6.0 #2 5.8 #9 5.9 #10 6.0 #16 5.4 #17 5.8 #28 5.7 #29 5.7 #40 5.5 #41 5.6 #52 5.7 #53 6.0 #64 5.7 #65 5.3 #76 5.6 #77 6.1 #87 5.5 #88 5.3 Averages out to 5.7 Looks like the bass needs the balance rail shimming...17 note bass. Is a higher Key ratio mean better or worse leverage? 5.5 vs 6.0 David Ilvedson, RPT Pacifica, CA 94044 ----- Original message ---------------------------------------- From: "Ric Brekne" <ricbrek at broadpark.no> To: pianotech at ptg.org Received: 8/7/2006 4:43:11 PM Subject: bechstein >Hi again David >The 4-3-2 / 3-2-1 etc are leading patterns and in general the more lead >peices you put in the heavier your FW's. In the last few years Stanwood >has developed his pattern leading to roughly relate to various FW curve >levels. The pattern leading distibutes key mass more evenly so as to >allow for both an even FW (static) curve and a more even key to key >inertia which gets into dynamic key <<weight>>. >I dont have his primer book so I cant reference it... but a 5.7 ratio >with a SW8 or 9 curve generally points to reasonably close to maximum FW >levels (depending on what BW you are specifying of course.) I believe >he also operates with a 5-4-3-2 pattern. >If you havent already down so... review the see-saw science ><http://www.stanwoodpiano.com/seesaw.pdf> side at his website. Put this >stuff into perspective with his balance equation and experiement with an >action model til you get it figured out. Keep it basic for now. >Cheers >RicB >Thanks Ric, >I might take you up off line...so I'm looking at my "Little Stanwood >Primer Book" at Appendix A...touch weight parameters table. Not sure >what the 3-2-1 compared to the 4-3-2 means other than more lead in the >keys? The 4-3-2 shows my 5.7 will get me in SW8 or 9 curve..right? >I'm going through the measuring again and doing the partial sample set >this time...just to make sure what I've got. I've gone over the >friction issues and now #16 is way different...D=43 U=17...too much lead >for that key...5 3/8" leads...BW is 30...way to low...so if I can get >it up to D=55 and U=23, I'll have BW=38... >You mentioned getting my BW down and I think I understand that now. >Too much downweight and too much upweight...in general...heavier hammers >will take care of some of that and FW changes will do the rest...? I >think... >David Ilvedson, RPT >Pacifica, CA 94044
This PTG archive page provided courtesy of Moy Piano Service, LLC