Hi folks, Forgive me lest I be breaching a topic that has been covered. I have searched the forums and haven't found this question adequately answered so I thought I'd bring it up as it is something I am shortly to be dealing with. We all know how piano plates are poured. We know and are very familiar with the size of the average back scale in everything from spinets to concert grands. My observation has been that, while concert grands benefit from a longer bass back scale than other (dare I say) lesser instruments, the backscale through the rest of the piano is not significantly different (usually) than what you find in smaller pianos.
While the cost of pouring a little more meat into a cast iron plate may have some mass production financial overtones compared to using larger backscales, is there any other reason that longer backscales have been abandoned? Many pianofortes have huge backscales.
I'm also aware that the act of moving the end of the backscale further from the rear of the bridge effects your ability to control downbearing. Is there any other aural or financial reason for keeping a short backscale in the opinions of all of you out there? I'm dealing in situations where the pianos I'm working with have no down bearing, no crown, bridge agraffes (for better or for worse, these instruments don't care about down bearing and for better or worse, they are out there and some people - like me - love them. Not that I'll plug my ears should a good pianist sit to play on a Steinway D for me... FYI: since my eyesight has started failing and I was trained to play from the printed text - something I greatly regret now - I don't get to play on my own as much as I'd like. Surgery will fix me if we can get insurance. Please Obamacare work!)
Back to topic: So, knowing standard piano design as well as recently revived approaches that avoid down bearing and crown, can anybody offer personal opinions concerning the effects and consequences of a backscale long or short? Obviously, I'm suggesting we throw out the obvious points of duplexing and downbearing as they pertain to this issue since those points are well taken and generally understood, I think.
I'd like to focus more directly on the various merits or problems associated with the use of a long muted backscale in an effort to create a lighter piano with less plate. As long as the plate that is there is solid enough, any vibrations leaking down the backscale should be returned from whence they came or do they? Ideas?
Also, this idea is meant to bypass the issue of overly short backscales which I happily concede restrict the vibration of the sound board and should be avoided at all costs.
So, any ideas on the various merits or detriments of long backscales? Perhaps opinions that such doesn't effect the piano at all?
There's always room for improvement.