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Topic: All pull versus "pull-release" changer mechanism |
Jim Bob Sedgwick
From:
Clinton, Missouri USA
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Posted 6 Feb 2007 2:17 pm |
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For a couple of years now I have heard of a pull-release guitar. Could someone explain this to me. All of the all pull guitars lower by releasing the raise finger and the string tension lowers the pitch. A return spring brings the string back to pitch after releasing the pedal.
Could someone explain the difference in the mechanism for an ignorant person?  |
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Bill Ford
From:
Graniteville SC Aiken
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Posted 6 Feb 2007 3:54 pm
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Look at a Sho-Bud Maverick, it is a pull release system..one that the changer fingers are pulled against the body of the guitar,and tuned at the keyhead, then released , and tuned at the changer end. To lower there is a spring loaded pivot that keeps the string against the body, and is lowered when the lever/pedal pulls the tention off. Tuned sharp at the keys, flat/low at the changer. The Carter website has a real good diagram of an all changer in action, also a push pull,Emmons type changer. Go to the website below, and click on changer to see how they work.
http://www.steelguitar.com/steelmap/maptop/maptop.htm
_________________
Bill Ford S12 CLR, S12 Lamar keyless, Misc amps&toys Sharp Covers
Steeling for Jesus now!!! |
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David Doggett
From:
Bawl'mer, MD (formerly of MS, Nawluns, Gnashville, Knocksville, Lost Angeles, Bahsten. and Philly)
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Posted 6 Feb 2007 5:01 pm
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An all-pull has a jointed changer finger, so that pulling on the upper part raises, and pulling on the lower part lowers or releases to top of the finger that holds the ball end of the string.
A pull-release is an unjointed single-piece finger. Pulling it rotates the top one way and raises, releasing it rotates the top the other way (by string tension) and lowers the pitch. On a simple Maverick type pull-release system, you cannot raise and lower the same string. The strings with raises rest against a tuning hex screw at the changer end plate, where the open string is tuned. Pressing a pedal or raise lever pulls the finger off the screw and against the body on the other side of the changer hole. The raise is tuned by the tuner at the keyhead. A string with a lower has the finger held against the body by a spring, and pressing the pedal or lever releases the finger to travel under string tension to the other side of the changer hole against the hex screw.
It is possible to modifiy a Maverick so that springs hold the finger in the middle of the changer hole. A raise pulls it against the body, and a lower releases it to mover against the hex screw. But it is very difficult to get that balance in the middle just right, and string tension is unreliable for the lowers. That's why the all-pull and push/pull mechanisms were invented. |
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C. Christofferson
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Posted 6 Feb 2007 6:57 pm
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Can i ask a related question here plz. On an all pull, where you have a knee lvr to lower the E (4th) 1/2 step, then you want another knee L which lowers the same E (4th) a whole step. Q: When you engage both knee lvrs at once, can you achive a lowering of the E (4th) three semitones and have all the combinations (one or the other or both engaged) accurately tuneable ? Thx JBS.
custom steel / recordings |
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David Doggett
From:
Bawl'mer, MD (formerly of MS, Nawluns, Gnashville, Knocksville, Lost Angeles, Bahsten. and Philly)
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Posted 6 Feb 2007 10:27 pm
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Don't know about all mechanisms, but on the all-pulls I have, If the E is lowered to D, the lever that lowers to Eb has no effect. If you hit both levers, you still only get the whole step lower to D, not a three semitone lower to Db.
However, if you have a whole step raise and a a half-step lower on the same string, activating both leaves you one half-step raised. |
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C. Christofferson
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Posted 6 Feb 2007 11:12 pm
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Ok DD that sounds logical. I was wondering that partially because in L. Green's Farewell Party vid, at :48 and 1:11 he apparently uses his RKL to lower the 4th a full step, but the phrases seem only possible (haha) if the 4th is already down 1/2 step before the full step lower. (It Can be played using a differnt combo of strings and pedal, but it doesnt sound as nice). But then, maybe someday it will unravel more clearly to me. Thx again, Cheers.
custom steel / recordings
Last edited by C. Christofferson on 6 Feb 2007 11:20 pm; edited 1 time in total |
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Billy Carr
From:
Seminary, Mississippi, USA (deceased)
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Posted 6 Feb 2007 11:20 pm changers
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| I've found with the pull release system, if you've finally figured out how it works, then it's not that big of a problem to work on but it's a headache figuring it out. To me, the all pull system is so much easier and quicker to adjust and move things around on and tuning problems are almost eliminated completely. |
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