Hello Richard, Thanks for a reply all the way from Norway! This piano is a Hamburg Steinway D. I had read (in an article by David Stanwood) that a 5.5 ratio was best or perhaps normal for a Hamburg D. But can that ratio vary from piano to piano as this one may be indicating? I agree with you that the numbers I gave did lean more toward a 5.7 and the numbers had been rounded down to the nearest 1 decimal pt. If I understand the procedure you're suggesting then I will proceed as follows: 1. Adjust the strike weight for each hammer to the weights listed in the number 9 curve. 2. Adjust the front weights to not exceed the maximums. (Or should they even be given a margin slightly below the maximum?) Should this improve the BW and get it to the desired 38? 3. Calculate the resultant Strike weight ratios. 4. Adjust ratios as necessary by change/shimming of fulcrum point near balance rail. Should every note have a 5.7 ratio or can there be slight variance on some notes. When you talked about knuckle angle are you talking about regulation of the jack to knuckle position? If so, are you saying that this can affect the swr? 5. Deal with friction problems. Basically your instructions seemed clear, just a few questions remain as listed above. Have a good day! Bob Hull --- Richard Brekne <Richard.Brekne@grieg.uib.no> wrote: > Hi Bob. > > Ok... looking closer at these numbers makes me lean > more towards a 5.7 > ratio then a 5.5 to begin with. Most of your Ratio > figures are truncated > downwards to the first decimal point. So some of > these are a better > seen as off a point higher. Plus I know the D model > normally works out > closer to 5.7 then a 5.5. > > So... I'd go with a number 9 curve... Starts at > 12.4 grams and ends at 5.8 > > see > http://www.stanwoodpiano.com/SW-HWstandards3.pdf > > Then install the FW maximums Stanwood published > along with the kit > information. > > If you WBW is correct at 9 grams, this should yield > you very close to a > 38 gram balance weight. Any inconsistancies that > you can measure after > installing the FW's and SW's are due to ratio > problems for each > individual key. These can most often be farely > effectivly be delt with > by checking and adjusting knuckle angle, regulation > issues that can > effect the ratio, and even shimming under the key at > the balance pin > hole to push the key ratio around just a bit.Once > you get BW smooth > enough, then even out friction levels. They are > reflected by uneven DW's > once BW is evened. > > In answer to you two questions below... > > --- Yes ... BW should stay fairly even over the > whole keyboard... but > may dip very slightly in the high treble... not > unusual. > --- Yes a number 9 curve will over nice tonal > projection. Perhaps in a > very very large concert hall you might want to go up > a bit. But heavier > hammers have a cost and you need to be ready to pay > that. My personal > preference for a top end limit is a number 10 curve. > Opinions vary on > this subject... but I see no point in getting > heavier. > > Hope this helps > > Cheers > RicB > > > > Bob Hull wrote: > > >Hi Richard, > > > >Thanks for your reply. > > > >you wrote: Stanwood suggests given SW curves for > > > > > >>each Ratio and BW... > >>tho you dont see that on most of the Smart Charts > >>published. > >> > >>If you give us some more specifics, perhaps we can > >>offer better advice. > >> > >> > > > >Where are these sw curves suggested in correlation > to > >particular ratios and BWs ? You referred to a > number > >10 curve. I'll give some more details here about > this > >action. This is with the new hammers. > > > >N SW D U BW FrontW R > WBWAvg. > >___________________________________________________ > >1 12.1 56 27 41.5 37.5 5.7 9 > >2 11.6 56 27 41.5 32.9 5.6 9 > >9 11.5 50 23 36.5 39.0 5.78 etc. > >10 11.7 53 28 40.5 32.6 5.4 > >16 11.4 48 20 34 40.8 5.7 > >17 11.1 48 21 34.5 37.1 5.6 > >28 10.8 48 25 36.5 32.1 5.5 > >29 10.4 44 19 31.5 35.2 5.5 > >40 9.7 31.6 > >*(40 10.8 48 26 37 31.6 5.5) > >41 9.6 40 17 28.5 33.1 5.4 > >52 9.5 44 22 33 29.2 5.6 > >53 9.3 46 21 33.5 27.2 5.5 > >64 8.3 46 27 36.5 20.3 5.7 > >65 8.2 44 26 35 19.3 5.5 > >87 6.6 49 29 39 6.8 5.5 > >88 6.4 50 34 42 3.5 5.7 > > > >(*C40 had 1.1 g temporarily added to the hammer) > > > >Do I understand that BW should be fairly constant > >across the keyboard while SW, Frontweight and > >downweight are going to smoothly decrease? > Although, > >downweight may just decrease from 52 to 48. > > > >Also, for good tonal projection is a sw of 12 > enough? > > > >I hope this info will help you advise me if you > don't > >mind. Thank you. > > > >Bob > > > > > > > > > > _______________________________________________ > pianotech list info: > https://www.moypiano.com/resources/#archives > __________________________________ Do you Yahoo!? New and Improved Yahoo! Mail - 100MB free storage! http://promotions.yahoo.com/new_mail
This PTG archive page provided courtesy of Moy Piano Service, LLC