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Topic: String pull info on spread sheet |
Charley Bond
From:
Inola, OK, USA
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Posted 20 Jun 2016 3:36 pm |
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Has anybody ever designed a string pull (distance and/or lbs of pull) requirement for 1/2 raises & whole raises for each string on a Pedal Steel Guitar.
That info itself (on a spread sheet) would be a great help for designing a Super PSG.
Foot pressure at 3 or 4 places on the pedal itself & 4 or 5 places on a bell crank. Same info needed to be documented for the knee levers.
This info would be great... |
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Lane Gray
From:
Topeka, KS
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Posted 20 Jun 2016 6:02 pm
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Are all fingers the same radius? Distances between the pull points and pivot points?
I'm not sure you could make a universal calculator with so many subtle variations in the geometry
_________________
2 pedal steels, a lapStrat, and an 8-string Dobro (and 3 ukes)
More amps than guitars, and not many effects |
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chris ivey
From:
california (deceased)
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Posted 20 Jun 2016 6:06 pm
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oboy, a new super steel
on the horizon! |
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Bob Hoffnar
From:
Austin, Tx
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Posted 20 Jun 2016 6:26 pm
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I've seen experiments done by Buddy Emmons and Bill Lawrence using a scale to measure string tension. I haven't seen a spreadsheet of it though. I'm sure someone has done it though. Bud Carter would be a good candidate. I had a long talk with him about his testing the resonant frequencies of every part of used in a steel. Paul Franklin Sr. Would absolutely know that information but wouldn't have a spreadsheet.
Most builders that I know would have profound insights on that issue.
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Bob |
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Georg Sørtun
From:
Mandal, Agder, Norway
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Posted 21 Jun 2016 2:45 am
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Some of the string-tension data can be extracted here...
http://www.daddario.com/upload/tension_chart_13934.pdf
It doesn't quite cover the highest-tensioned strings on a PSG, but it is close enough.
As I personally haven't been interested in replicating the regular bridge/changer construction w/fingers etc., I have only roughly measured the longest stretch-change on my PSGs, which is an about 2.2mm increase in stretch for a .0115 third string on E9 to go from G# to A. That is measured on the string itself where it passes over the bridge, so finger-radius and other dimensions don't matter.
All other strings on my E9/E-extended PSGs require less string-stretch change for a half or full tone raise or lower. That's true also for the full-note lower I have on third string, and the 5-half-note lower I have on my extended low E string - a .056W.
As neither string gauges for a particular note, nor anything else in the pull-train, is, or can be, "entirely set in stone", I find more detailed data to be of little interest.
So, for my own "linear keyhead changer" design I have concluded that +/- 3.0mm "free-play" for string-stretch changes will cover what any and all strings can handle before breaking or going dead, and left it at that. |
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Jim Palenscar
From:
Oceanside, Calif, USA
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Posted 21 Jun 2016 6:57 am
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Terry Downs made one a number of years ago. I would be happy to send anyone who wants it a copy. It is based on a 24" scale but changes are easily made.
Last edited by Jim Palenscar on 22 Jun 2016 3:16 pm; edited 1 time in total |
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Ian Worley
From:
Sacramento, CA
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Stephen Williams
From:
from Wales now in Berkeley,Ca, USA
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Posted 21 Jun 2016 10:54 am
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AFAIK work done is measured by force x distance
so all things being equal:
pedal travel x distance = string pull x distance
Meaning you either have easy pedals with long travel
OR hard pedals with short travel.
unless the Super PSG has turbo assist! |
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