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Topic: How to Keep Slack in Carter Pull Train |
Dan Robinson
From:
Colorado, USA
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Posted 7 Apr 2018 6:22 pm |
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Looking for help with my Carter steel. Pedals are easy to press, sometimes too easy. The mechanism has nothing to hold pedals UP. Just the weight of the pedal takes up slack in the pull train. A slight touch causes pitch to change.
I want to add some spring tension, without doing anything I can't undo, so drilling holes is out.
I have an idea of placing a compression spring over the pedal travel-stop screw. I tried this on one pedal, with some odd spring that was laying around. It's not up to the job. I know nothing about finding the right spring, but I hope this approach has some merit.
I need some advice, and welcome your suggestions.
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Larry Bressington
From:
Nebraska
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Posted 7 Apr 2018 8:05 pm
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Have you tried stiffening the pull train by moving the pull rods to a higher hole on bell crank? This will shorten the throw and also stiffen the feel, back off nylons when doing so and you have to adjust the pedal stop screws so the pedal travel is less, The pedals will be less sensitive with this.
I like my pull train to have about the thickness of two fingernail slack in the nylons when all is adjusted right for string wear and temp changes
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A.K.A Chappy. |
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Jim Palenscar
From:
Oceanside, Calif, USA
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Posted 7 Apr 2018 8:50 pm
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| If you get the pulls timed correctly you'll find that the guitar plays better. If the guitar is not timed properly one string will activate with the least bit of pressure until the other one kicks in. You can probably infer that "timing" on a pedal steel refers to a setup procedure whereby changes start on all strings employed by the pedal or lever at the same time so that the musician in unaware by feel that there is more than one thing going on. Timing is achieved by employing different positions on the bellcranks and changers when placing the pullrods to increase or decrease the length of travel needed to affect the change desired. I generally start with the one that requires the least movement - ie. the 10th string on an E9th 10 string using a .036 or .038 gauged string putting the pullrod as close to the crosshaft and as far away from the changer axle as possible in order to achieve the easiest and longest pull possible. I then time the 5th string (.017 or .018) pullrod to get it to start at the same time both ending in a C#. The disparity in the placement of the pullrods is probably greatest on the B pedal between the 6th and 3rd strings. The freeplay before any change starts is absolutely necessary to insure that the changer is coming back to the zero or neutral position for each string and is generally easy to modify. |
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Dan Robinson
From:
Colorado, USA
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Posted 9 Apr 2018 12:24 pm
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Larry, good point. Useful where faster changes are needed or to remedy "too easy."
Jim, I appreciate you taking the time for that detailed explanation. It's fantastic, and packed with education! You should have charged more, lol.
Right on the mark. A quick check shows that timing needs attention on both my A and B pedals. On both, the raise of the smaller (higher pitch) string begins sooner. Here we go, someone please jump in if I got this wrong.
On Pedal B I need to increase the pull-length of the 3rd string raise (or decrease pull-length on string 6). To increase Pull-Length: (a) move closer to the cross shaft, and/or (b) farther from the changer axle. The B/3 pull rod is already in the highest bell crank slot (nearest to the cross shaft). It's in the raise finger's 3rd hole down (away from the axle). The 4th hole is empty. So move the B/3 rod into the 4th hole in the raise finger. Back off nylons, adjust, if raises don't reach target, then adjust the pedal's stop-screw to allow more travel, rinse/repeat.
My A pedal has the same issue, so "tune in next week.... same Bat-time, same Bat-channel." In this case, same bell-crank slot, same raise-finger hole.
Is that about right? Did I get it backwards? I was a gifted youngster, with tremendous aptitude for taking things apart. Reassembly was not in my wheelhouse. |
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Larry Bressington
From:
Nebraska
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Posted 9 Apr 2018 12:39 pm
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With guitar up-side-down......To increase pull length, move rod to higher point on bell crank (Away from the undercarriage) and the lowest hole from axle on changer.....This will also increase the feel.
If i remember, i run my 3rd string on highest hole on bell crank and lowest hole on changer from axle, but on 6th string its on second hole on changer and maybe 2nd hole on bell crank, are you running a plain or a wound? big difference in pull length.
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A.K.A Chappy. |
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Dan Robinson
From:
Colorado, USA
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Posted 9 Apr 2018 3:40 pm
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Changes to A/5 and B/3 are now done. It went pretty well despite a couple of mistakes I had about where rods were connected to bell cranks. And it didn't take too long to find the nylon nut that I dropped, or the brass "dog-bones" that vacated their bell cranks without giving 30-days notice.
Good learning experience. Maybe next time I'll turn the guitar over and put it on a bench.
Jim Pali, thanks for calling my attention to it, and for the excellent mechanical guidance. Correcting the pull timing was necessary. I just didn't know enough to realize it. It is demonstrably improved now. Things are moving up... TOGETHER!
Larry, oops, we're upside down.  I opened a can of worms with "increase length of pull." I meant a change where a longer movement of the pull train is needed to reach the target pitch. BTW, my str. #6 is plain. |
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Larry Bressington
From:
Nebraska
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Posted 9 Apr 2018 4:20 pm
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Good man Dan, sounds like you got the learning curve down already, it is a bit confusing i must admit, it's hard to explain sometimes unless you explain it all the time and have a system down pat...I'm never at a guitar so it's going off memory.
Here's how i remember it when i need to; Point your first finger up in the air and wiggle it side to side, you can see the highest point of movement is at the top by the fingernail and the knuckle moves only slightly, and that represents the bell crank, the longest amount of movement is at the top. A plain needs much less pull movement that a wound... I hope that makes some sense out of all this NON sense. 
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A.K.A Chappy. |
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