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Topic: p/p 2nd string lower questions |
Joe Gorfinkle
From: California, USA
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Posted 30 Sep 2007 9:45 am
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I have a '78 Emmons D10 and have been having problems with my RKR on my E9neck ( d#>d>c# ) returning sharp. what should I be doing to find & fix this. I also have a problem w/lowers on C6 neck not having enough range. |
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Jerry Erickson
From: Atlanta,IL 61723
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Posted 30 Sep 2007 3:29 pm
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Joe, Is your raise finger should be resting against the body? If not it should,unless you're raising it. For your C6 problem you might need to move the collar on the lower rod closer to the bell crank. ow old are your strings? This can affect how well your guitar tunes up with the pedals. |
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Joe Gorfinkle
From: California, USA
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Posted 30 Sep 2007 4:57 pm
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Thanks Jerry, so the raise screw should go all the way in on the lower strings like D# .E9 strings are relatively new...C6 are pretty old.. |
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Jerry Erickson
From: Atlanta,IL 61723
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Posted 30 Sep 2007 6:02 pm
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No, the raise finger should be pulled up against the body. There should be a spring attached to the raise finger and the othe end attached to the bracket that has the return springs attached to it. In this case, it is the return spring. The lower rod pushes on the raise finger until it hits the lower finger. That screw that it hits is where you tune your half step. Then you keep pushing and both fingers hit the endplate screw, where you'll tune the full step lower. If the raise finger is not resting on the body when you release the KL, the return spring needs to be tightened. You can adjust the feel of the knee lever with that spring. How easy or stiff do you want it to be. |
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richard burton
From: Britain
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Posted 30 Sep 2007 10:20 pm
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Jerry is quite correct in his explanation, assuming that the 2nd string is not raised.
In the following sketches, note that there is no collar on the lowering push rod (it's meant to be like that )
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Joe Gorfinkle
From: California, USA
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Posted 1 Oct 2007 7:05 am
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I get it...very cool! Now I can also tune the half stop |
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Tony Glassman
From: The Great Northwest
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Posted 2 Oct 2007 2:13 pm
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Exactly right re the half-stop detente:
The more you tighten the "return spring" ... the more pronounced the 1/2 stop will feel.
Keep in mind, that if you tighten the spring too far the d-->c# will become uncomfortably stiff. |
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Earnest Bovine
From: Los Angeles CA USA
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Posted 2 Oct 2007 8:05 pm
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I would do it so that the push rod doesn't start pushing anything until after you have already lowered the half step (to D on the 2nd string). In other words, the first half of the knee lever travel only releases the raise finger so it falls back from D# to D. That way, the two half-step changes are independent, and if you like, you can set it so there is a "dead spot" in the middle where the knee lever moves but the string stays right on D. For me that makes it easier to play the half stop in tune, especially when releasing from the full step lower.
You can also put half stops on 2 strings, same lever, and be sure that the half stops as well as the full stops are in tune. Here it is on RKL with half stops on strings 2 and 7, plus D -> -C# on string 9. (Also, string 12 E -> ++ F#, which you can't see clearly here.) The long spring at the far side of the picture pulls 2 D -> D# and 7 F -> F# when the lever is not engaged.
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richard burton
From: Britain
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Posted 2 Oct 2007 9:30 pm
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Earnest,
If I'm understanding this correctly, does that make your 2nd string half-tone drop similar to a pull-release changer, with the finger held in the raised position by a spring on the knee lever bellcrank?
That would certainly give better accuracy at the half-tone point, as a small delay could indeed be built in when setting the lowering push-rod.
Now where did I put my box of springs....... |
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Earnest Bovine
From: Los Angeles CA USA
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Posted 2 Oct 2007 10:27 pm
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Right, it could be called a pull-release on the 2nd string, and also on the 7th string in this case. The spring that holds them both in the raised position is the long one at the back of the first photo. When you push the knee lever, that shaft rotates clockwise, allowing the shaft just to its right to rotate counter-clockwise, releasing the raises on strings 2 and 7.
Maybe this photo is clearer:
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Dave Magram
From: San Jose, California, USA
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Posted 2 Oct 2007 11:54 pm
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It sounds like Earnest has come up with a better way to handle that half-stop.
Richard, since you seem to understand it, would you mind posting one of your marvelous diagrams showing this "pull release" approach?
Thanks,
Dave |
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richard burton
From: Britain
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Posted 3 Oct 2007 9:17 pm
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Dave,
I have done a sketch with the finger in the raise position.
The knee lever/bellcrank is not representative of the actual Emmons design, it just demonstrates the principle.
You may need to magnify the sketch to read my writing.
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Tony Glassman
From: The Great Northwest
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Posted 3 Oct 2007 11:20 pm
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My D#-->D-->C# consists of a single additional spring which attaches :
from the bottom hole of the 2nd string raise finger (the hole farthest from the string).....
and connects to the 2nd string hole on the 10-hole bracket to which the lowering return springs are attached.....This holds the raise finger against the body at rest.
There is no collar on the lowering rod at the lowering finger. Engaging the knee lever pushes the raise rod to neutral where it meets the resistance of the lowering finger/return spring to give the "C#-->D". The lever is then pushed further to C# positive stop.
It's pretty simple, and requires the addition of only the one spring. I think this is a factory Emmons set-up for a lowering 1/2 stop.....The D#-->D detente becomes more pronounced by increasing tension on the on the lower return spring.
I'll try and post some pix tomorrow if anyone is interested.
Last edited by Tony Glassman on 5 Oct 2007 7:14 am; edited 2 times in total |
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richard burton
From: Britain
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Posted 4 Oct 2007 11:21 am
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Tony Glassman
From: The Great Northwest
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Posted 4 Oct 2007 11:04 pm
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Here's the photo of the double-stop spring.
I temporarily hooked some of the pull rods over bell cranks to better expose the spring for viewing. Normally the spring and pull rods are correctly aligned.
Also, I neglected to mention that aside from the additional spring you need a single short piece of pullrod and 1 collar
(I know....the under-carriage is way overdue for a good cleaning and delousing.)
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