Phil, I hope you don't mind--I've put this back on pianotech. The scans went out in two batches and it looks like there will be yet a third. I should have waited More comments below.... Del ------------------------------------------ > From Greg Newell (I think) > Folks, > These are some very interesting ideas. Some quick observations if > I may. While the sandwiching of wood and steel may offer a structure that > is capable of handling the stresses we require of it I'm not so sure this > is the way to go. Does not this construction disallow any attempts at > rebuilding in the future? How would one replace a pin block here? One wouldn't. It's a disposable piano. Much like many of the pianos--both grands & verticals flooding the market just now. > > Also the > 20% larger soundboard area is not necessarily a good thing if more of it is > tone robbing without any sort of cut off bars or the like. It's not at all a good thing. But then, this was designed and built back in the days when it was still assumed that soundboards were "amplifiers" and bigger was better. > > I like the fact > that the ribs are crowned and therefor will hold a more permanent crowning > of the soundboard. The bridges still seems to be a little funky though. In > the center picture in the first attachment I see that the bass bridge is > still, at least partially, cantilevered. This seems to have resulted in a > very short back scale length in order for them to get their bragging rights > of a 62" long speaking length of A0. Who cares? The marketing department and the local salespeople care. Other than that, no one cares. Yes the backscale is too short and the bass bridge is cantilevered. Though, considering the type, not by much. Neither of these 'features' is critical to the string panel concept and could easily be modified (at the factory). > > Also the long bridge seems to be split in two to allow for the heavy plate > strut. This must have an interesting affect on the tone in that area. > The long bridge also appears to be very tall, if I'm getting the right picture > from the pictures. I would be concerned about all that mass at the top end. Yes the long bridge was split. But, if you look at the picture of the back of the soundboard you will see a coupler. I don't recall that there was any particular tonal problem across this split, but I only saw the piano at a trade show and didn't have a chance to really evaluate the tone quality--or lack thereof. And yes the bridge was a bit on the tall side. The string panel was relatively thick. > > --- Other hype turned me off too but these are the first ones I saw. I > won't belabor all the points in the articles but I am happy that at least > the status quo is being challenged somewhat. Thoughts? > > Greg ------------------------------ >From Phil Ford (I think): > 'Computer machined steel is sandwich or strata constructed in layers'. > > This makes it sound like they are laminating sheets of steel together. I > wouldn't think that would be the case. Why would you? I think you would > machine the face plate to the thickness, or thicknesses if you wanted it > different thickness at different places, and bond it to the core. Some of the > pictures made it look like the steel faces were on both sides of the core > (which is what I would expect) and others made it look like the steel face was > only on one side. Maybe it was just the camera angle. It's camera angle. The construction was three-piece: the faces were sheet steel (about 1/16" [1.5mm] or 1/8" [3mm] thick--I don't remember exactly) bonded to what looked like MDF. The MDF was approximately 1-1/4" (32mm) to 1-1/2" (38mm) thick. There was a separate steel bass hitchpin riser. In the one edge-on picture of the pinblock section what looks like a thick steel backing was a steel backing--it was probably needed to add stiffness across the tuning pin area. > > 'Many times the yield strength of conventional studios'. > > I found this hard to believe. Cast iron is pretty strong in compression. > Most of the strength of this panel is from the steel face sheets, which are > relatively thin. The plate struts are wide, so there is still a fair amount > of steel cross sectional area, but probably not much, if any, more than a > typical cast iron strut. According to the engineer I talked to there was 'far less' twisting going on while the backs were chipped to pitch. Compared to what--I don't know. > > 'Extra layers of steel within reinforce critical areas on the panel where > needed.' > > I assume this means that they have steel under the face plates in the areas of > the hitch pins, rather than having them driven into the wood core. No, mostly backing for the tuning pin area, as I recall. > > I notice also that the hitch pins for the bass section are on a separate block > which seems to be bolted onto the plate. Yes. For height. > > 'Wood product core'. > > I don't know what this means. There's really no need for the core to be high > strength, so I would use the lightest and/or cheapest wood that I could. I > assume that they did the same. It means MDF. > > 'The structure allows the elimination of the conventional back frame and > posts'. > > This is a subject that has been discussed before. This seems to assume that > the purpose of the frame is to help support string load. I don't think that's > the case, so I don't see any less reason to have a back frame on this piano > than on a more conventional piano. The back assembly in most verticals does contribute to the overall rigidity of the assembly in that it keeps the plate from twisting. The actual string load is born by the plate. > > '15% more of the tuning pin to rest in the pinblock'. > > I don't see that as an advantage. If that's all you want, then use a longer > tuning pin. The advantage which they fail to mention is, since the face plate > appears to be thinnner than a typical casting, the distance of the string to > the top of the pinblock can be less, resulting in less tuning pin bending. Or, even better, an open-faced block. > > It wasn't clear to me from the pictures if the steel face plate over the > tuning pin holes is counterbored, so that the tuning pins are not contacting > the steel face, or if the hole is drilled through steel and pinblock and the > tuning pin driven in so that it's contacting both. Sorry, I don't remember. > > The tuning pins are nicely spaced out in the field of the plate, which is nice > from a structural standpoint. But I believe Del indicated that this actually > caused a problem in service. I tried to find an older e-mail on this subject > but couldn't lay my hands on it right away. I believe that some of the treble > tuning pins being right next to the pressure bar and some being very far away > caused tuning problems. Del? Other than fuss with a few unisons I did not actually tune one but was told by several that it made tuning quite difficult through the upper treble. > > One additional thing that I found interesting about this plate is that it's > gold. Since this is supposed to be the latest high tech thing why not make it > look different? Why try to make it look like a conventional piano plate? Tradition? > > 'Monolithic Construction'. > > I wasn't completely clear on what this was, but it sounds primitive (I think > the marketing department should have selected a different word). It was intended to indicate that all of the structural strength came from the string panel and did not depend on a separate back assembly. But, as you point out.... Del
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