Right, we shortened the regulating screws by about 3mm which required re-grinding the ends to a point and sizing the holes (3:1 water/glue) as the screws were barely finger tight. Thanks for boiling this down for me David. So, basically whether having the hammer perpendicular at strike is more or less critical than (minor) implications to touch. (?) Yamaha for instance has a longer bore, bringing touch factors you mention into play, however they seem to negate this by altering hammer rake-angle. (Blow distance is similar to the shorter bore hammers). All things considered, I think I'll go back to the 51mm bore length for the next set of hammers, which in the case of this piano (in a recital space) will likely be the new Weickert Special felt. thanks all, Mark C. On 02/06/2010 10:36 AM, David Love wrote: > The only issue with the longer bore and thinned rest cushions that I > can think of is if the shanks contact the balancier regulating screws > on a hard rebound. The touchweight dynamics can be influenced by the > shank starting at a lower angle. The increased travel along the > horizontal axis can increase the force required to initiate the key > stroke when compared to a higher starting point. > > > > David Love > www.davidlovepianos.com > > ------------------------------------------------------------------------ > *From: * Mark Cramer <cramer at brandonu.ca> > *Date: *Wed, 02 Jun 2010 10:00:16 -0500 > *To: *<caut at ptg.org> > *Subject: *Re: [CAUT] Steinway extra-bore-length > > Okay, that's a rationale I can live with. > > In this case however, with *thin* rest cushions I actually *can* bore > the hammers to full length (51mm, if memory serves) and still move the > action in /out without angling (pitch) the hammers. > > BTW, regarding stack height, maybe I wasn't clear enough... I have NO > intention of tampering with this. There is simply no need. > > What I should've asked perhaps is what good reason is there for *not* > lengthening the bore when it will solve a strike issue, especially > when case fit isn't a problem? > > Steinway obviously couldn't do this being limited to their stock bore > lengths, and I wouldn't either, from a manufacturer's point of view. > > This particular supplier however had strong opinions about extra > bore-length affecting the performance of the action. I don't get it, > and would appreciate someone enlightening me as to why, if in fact it > is an issue. Strike-weight wouldn't be that big an issue. > > Otherwise, I'm planning to go back to the 51mm bore, and my only > caution to others calculating a bore-length longer than stock, is make > sure it all fits back in the piano. > > thanks, > Mark Cramer, > Brandon University > > PS I have no issue whatsoever with a blow-distance that results in > bass hammers rubbing the pin-block going in and out of the case. All > performance objectives considered. > > On 02/06/2010 9:02 AM, David Love wrote: >> >> So the standard bore of 1 15/16” in the tenor treble increased to 2 >> 1/16” was the difference between being able to get the hammers under >> the block? If that’s the case then practicality reigns supreme. Use >> the maximum bore that still allows the hammers under the block and >> angle the hammers back to get them at 90 degrees at string contact. >> There are many examples of pianos that do this without any problems >> and an extra 1/8” of travel requires a minimal angling especially >> when combined with the upward slope of the strings from termination >> to bridge. >> >> David Love >> >> www.davidlovepianos.com >> >> *From:* caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] *On Behalf >> Of *Mark Cramer >> *Sent:* Tuesday, June 01, 2010 8:43 PM >> *To:* caut at ptg.org >> *Subject:* [CAUT] Steinway extra-bore-length >> >> A week or so back, Jon Page mentioned the correct method of >> calculating hammer-bore length. >> >> Thanks for that Jon, it's the same method we use, excepting where the >> hammers are deliberately pitched, but here's a funny story from a few >> years... okay, a decade ago: >> >> I was preparing hammers for a 1980's D and found that bore length >> worked out about 3mm (1/8th) longer than spec. Since we tend to buy >> our hammers un-trimmed and extra-length, it was no problem to bore >> them with plenty of tail length. As a caution, I tested samples on >> the bench and all was fine. Fine... until installing the action that is. >> >> The action wouldn't fit back in the piano... even with the shanks >> buried in the cushions, no deal! (that was the chuckle part, the rest >> is pretty boring, but I do have a question) >> >> So, we thinned the cushions and even shortened the balancier height >> adjustment screws. All worked wonderfully, and /three years later/ I >> repeated the dimensions with the next set of hammers. / >> >> Three years later again/, I was pressed for time and ordered some >> pre-hung aftermarket hammers. The supplier was quite adamant that the >> hammers be bored to original spec, even though this would result in >> over-strike. Knowing I had room to push the action back (return to >> factory position), I went along with their advice, even though it >> meant replacing cushions, etc. >> >> Now it is /"three years later" yet again/, and time for fresh hammers. >> >> I really like the idea of the hammers being at right angles to the >> string, and the shanks horizontal at strike, which is the result we >> get with Jon's measurements. However, I wonder about the implications >> of the extra-long bore... aside from the need to get the action in >> and out of the piano that is. >> >> Raising the stack (3mm) would take care of things, but this is really >> a very efficient action, and I neither want, nor see a need to tamper >> with that. What's more, I can't say I really noticed a difference in >> performance with either bore dimension. >> >> The Question: >> >> So, what are the rest of you (and Jon) doing in this situation, and why? >> >> thanks, >> Mark Cramer, RPT >> Brandon University >> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/caut.php/attachments/20100602/a642f6ef/attachment.htm>
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