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Topic: Rodding advice needed |
John Polstra
From: Lopez Island, WA, USA
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Posted 4 Nov 2011 1:39 pm
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I have a 12-string Sierra Crown series instrument in the E9/B6 universal tuning. String 9 is tuned to B, and my RKR raises it to D. This has always worked OK with Jagwire strings, but today I restrung it with SITs. Now RKR is no longer able to raise the string all the way up to D. The string is the same gauge (0.036W) in both sets, but for whatever reason, the SIT string needs a longer pull. (RKR was borderline even with Jagwire strings.) So I'm trying to figure out how to shuffle around the rodding on that string. Here's my copedent and my rodding chart:
The rod is already in the maximum-throw position of its bell crank, so I guess I have to move it at the changer end to a hole closer to the strings. Both of those holes (A and B) are occupied, though, so I have to move one of the other changes down to hole C.
I really don't want to mess up the timing of my A pedal. Can somebody who's done this before tell me what's most likely to work the best?
Thanks,
John |
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Bill Moore
From: Manchester, Michigan
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Posted 4 Nov 2011 1:59 pm
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I'm not familiar with Sierra guitars, but the lever should have some adjustment for travel. It seems like that would be the only thing you need to adjust. There is probably no need to change any of the rod positions at the changer, just add some travel to the knee lever. |
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Jerry Overstreet
From: Louisville Ky
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Posted 4 Nov 2011 2:23 pm
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The easiest and most obvious thing to do is restring it with a Jag, of course. I think the wire core is a larger size on them...else... you've substituted a nickel wound for a stainless.
Rodding on a Crown, especially on a Uni, gets complicated pretty quickly, so I wouldn't do that unless it is absolutely necessary.
I might follow Bill's suggestion to allow a little more travel on the KL. What follows is that you'll have to retune all the strings on that pull probably and you'll have a little extra movement on the lever.
Below is a shot of the RKR lever connecting linkage at rest. The nylon eccentric cam on the far left of the pic is the stop. They're a little stubborn, but after you loosen the cap screw, you can rotate it away from the rail, with lever actuated against the stop, a bit to allow more travel.
 |
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Pete Burak
From: Portland, OR USA
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Posted 4 Nov 2011 3:17 pm
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I'm thinking something else is going on.
I don't believe the string "brand" is causing enough of a change in throw to requiere a rod position change, assuming the "guage" is truely the same.
Being on RKR, and given it barely made the pull with the old string, I'd check the reversing mechanism and probably re-optimize that portion of the linkage assembly.
While you want a little play at the changer finger, you really don't want any play at all in the reversing mechanism.
Here's one test...
Take an allen wrench or screw driver and manually push the raise changer-finger for that string and see how far it raises.
If it makes D with no problem, you've ruled out the changer. |
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Jerry Overstreet
From: Louisville Ky
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Posted 4 Nov 2011 3:46 pm
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Perhaps....one can actuate the lever with the guitar upside down and note whether the adjustable linkage is pushing the stop all the way against the rail when actuated, which I assumed was implied by the photo. The linkage is shown on the left in the photo I posted.
BTW, the stop in my photo is probably smaller than yours as I swapped some stops around to have more travel on the RKR as I tuned it to D#/D/C#.
Because the condition appeared with the string change, that would be the first thing I would suspect.
It is a fact that Jagwires have a different size core wire, just ask b0b,....also a different alloy of string winding, stainless v nickel wound, will affect the stretch and amount of travel required to bring it to desired pitch. Also, it wouldn't be the first time a string pkg. was mislabeled or a string mispackaged.
Tuning a Crown change from D# to D is well within it's limits however, so it's possible there is a loose string ball end or other obstruction in the changer. Something to check along with the other suggestions. |
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John Polstra
From: Lopez Island, WA, USA
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Posted 4 Nov 2011 4:03 pm
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Wow, thanks for all the quick advice, guys! I was able to increase the lever travel a little bit, as Bill and Jerry suggested. That solved the problem perfectly, and it took all of 60 seconds to do it.
Pete, I should have mentioned that I knew the limitation wasn't in the changer. I could easily get the string up to pitch by tuning the change while pressing RKR, but then when I released the lever the string didn't go all the way back down to B. That is, there was still some tension on the pull rod at that point.
Anyway, it's working fine now, and I'm glad I didn't have to futz around with the rodding. Thanks again to all of you!
John |
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Pete Burak
From: Portland, OR USA
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Posted 4 Nov 2011 4:06 pm
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All's well that ends well!
BTW, I really like your copedant/rodding-chart system.
Makes it real easy to visualize leverages, etc. |
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John Polstra
From: Lopez Island, WA, USA
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Posted 4 Nov 2011 4:25 pm
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Pete Burak wrote: |
BTW, I really like your copedant/rodding-chart system.
Makes it real easy to visualize leverages, etc. |
Thanks! Here's another chart I made that's handy for tuning at the changer end:
It's a view of the changer end of the guitar, where all of the changes are tuned. The columns are the strings, and the rows are the holes in the changer. All of the changes for a given pedal or lever are the same color. This chart makes it easier to find the right tuning nut to tune a given pedal on a given string. I know it's not that hard to find the right tuning nut, but every now and then I'd tune the wrong one, and that's annoying.
Of course, if I had used the time I spent making this chart to practice instead, I'd be a better player.
John |
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Charley Bond
From: Inola, OK, USA
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Posted 17 Nov 2019 2:26 pm Copedent setup
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Here is setup I developed, I've been trying to find the time to do one for the Sierra...
 _________________ Steel Guitar players are members of a Special Family |
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