Grand piano design - parallel vs angled strike line?

[Overs Pianos]

Jon and list,

Jon wrote;

>Today I crossed paths with a S&S C. The stack and balance rails were angled.
>A quick check with a ruler showed  ~.50 Key Ratio on keys 1 & 88.

Thanks Jon. I was aware that when the strike line is angled, the 
balance rail must also be angled relative to the key fronts to 
maintain the desired key ratio throughout  the compass of the 
instrument. All Steinway models B, C and D incorporate an angled 
strike.

The contributions to the list on this subject were very interesting. 
I raised the topic in the first instance since I was unconvinced 
about the wisdom of angling the strike on the larger grands, and 
following the responses by many, I still remain undecided about this 
issue (there are many arguments for and against). A 293 cm concert 
piano design I have on CAD presently has an angled strike. But I will 
construct a second spreadsheet of an alternative 293 design with a 
parallel strike, to see where the design outcome leads me.

Thanks to all for your contributions. The 225 Samick has a parallel 
strike, whereas the Yamaha C7F (a design which shares many 
similarities with the Samick 225) has an angled strike. So many 
different solutions - the high road and the low.

The use of the spreadsheet when designing

I construct a spreadsheet to design the entire XY overhead view of a 
proposed grand piano. When the basic case dimensions have been 
decided, the center coordinates for the concave on the bent side and 
the center coordinates of the convex curve immediately to the back of 
the concave [which sometimes has a short straight section between - 
on longer pianos] are solved using simultaneous equations. Each time 
the case dimension are adjusted, the two centers need to be resolved 
again to complete the case equation.

I have found the spreadsheet approach to be very useful, since new 
designs can be derived more quickly using an existing sheet as a 
template. These sheets get to be pretty large, with around 8,000 to 
10,000 cells in the main worksheet.

Regards to all,

Ron O
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Website:  http://www.overspianos.com.au
Email:      mailto:ron@overspianos.com.au
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