Originally Posted by
FBinNY
As I and others have said, tension can be used to match the spoke tensions within a wheel, and can be a useful and fast method for doing do.
But pitch cannot reliably be used for absolute tension.
It depends on how much technology you can accept.
Not only are there too many combinations of free span and gauges to make a meaningful chart
Assuming people would need to use a chart is anachronistic.
Most people already have at least one portable computer (in the form of a phone, tablet, or laptop) with a microphone that makes it trivial to measure a spoke's resonance via a FFT.
It would be painless to run a program on it to which you feed the data you gave your spoke length calculator, its output, and nipple plus spoke types.
That means that there are 2 sliding variables; free length and target pitch; so establishing the database would be one hell of a chore.
You don't need a database. One of the numerous spoke length calculators will output spoke length, ERD, and hub geometry which can be used to calculate free lengths. In theory you could look at nipple type which affects where the threads start; although 1-2mm of variation is inconsequential compared to 200-300mm of spoke length. Butting length should affect things too but not enough to matter.
There are reasonable default tensions that won't lead to wheels which collapse, wheels which go out of true, or stress cracks in the vast majority of rims with few currently manufactured exceptions. That default, rules for exceptions, or a user input will combine with the free length and spoke cross-section to produce a calculated target pitch. As more people use the tool and contribute there will be more entires producing optimal higher tensions.
Then when you were finished, it would be totally useless since only a small percentage of people have perfect pitch and can identify or reproduce a pitch without a pitch pipe or piano.
A $25 MSRP computer (Raspberry Pi for example) has perfect pitch (from an FFT which converts things into the frequency domain). Everyone with a laptop made in the last five years, tablet, or smart phone already has a computer that's at least as powerful and includes a microphone which means their incremental cost is that of the software. That will be zero when wheel building geeks come up with formulas or software for their own use (If I was inexperienced enough for such a thing to be technically interesting or built more wheels than my wife and I needed for our own use I'd do it. Other good enough geeks are early enough in their careers and/or build enough wheels) and share for free. When that is not user friendly enough there will be be people with motivation and aptitude (less than the people who figured out how to do it) to make it so. In the cycling problem space some one added a tool to Golden Cheetah using Chung's virtual elevation model for aerodynamic and rolling drag estimation allowing non-technical users with power meters to ride around appropriate courses to net usable information on position and equipment drag where the alternative is waiting for the next group deal, flying to Washington state, and paying hundreds of dollars for their time in the UW low speed wind tunnel.
People who want to do things to old ways will still be able to. Although I have access to CNC equipment I still use my manually operated power tools to make sub-templates, master templates, and then the wood parts I need because using the robots would usually be too much like what I do for my day job for maximal enjoyment. More idealistic Neanderthals limit themselves to hand tools.
People who just want results will be able to poke their phone a few times and have the right magic happen apart from the wrench turning and accompanying beer drinking.