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Topic: C pedal problem - help! |
Michael Hunter
From:
Traverse City, MI, USA
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Posted 30 May 2006 8:39 pm |
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I have an older BMI S-10 with a C pedal that's giving me fits. My 4th string E-F# change simply does not work correctly.
After tuning the F# at the endplate, I'll release the C pedal. Depressing the C pedal again causes the F# to go sharp of the pitch I had tuned it to initially. If I retune the F# again (this time flattening the pitch), after releasing the pedal it will subsequently go flat when I depress it (the C pedal) again. The open 4th string E stays in tune the entire time, mind you - it's rock solid.
Needless to say, this inability of the F# change to remain in tune renders my C pedal pretty much unusable. I don't have this problem with any of my other pedal or knee lever changes, even the 5th string C pedal B-C# change. I'm hoping someone will have some insight on my problem, 'cause it's driving me nuts.
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Lem Smith
From:
Long Beach, MS
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Posted 30 May 2006 9:40 pm
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Michael,
My first thought would have been something wrong with the pedal stop, but since you said the 5th string works ok on the C pedal, I guess that would rule that out.
Maybe check to see if there could be something binding in the changer on the 4th string raise...maybe not letting it go back into the full rest position correctly after tuning. May not be, but wouldn't hurt to check if you haven't already.
I had an older ProIII Sho~Bud once that did something similar with the a pedal and the 5th string. If you let half way off the A pedal, then pedaled down again, it would go sharp...but only if you half pedaled. What was wrong then was the spring on the endplate needed loosening just a little bit. Maybe look into that if the BMI has those springs. It's been so long since I've owned a BMI, I really can't remember.
I know this isn't much, but I hope it helps.
Lem |
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Jim Palenscar
From:
Oceanside, Calif, USA
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Posted 30 May 2006 10:56 pm
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| A couple of things that I've seen can cause this on BMI's. One is a loose bellcrank that is pivoting on the crossbar that it is connected to and the 2nd is that sometimes the spacer behind the tuning nut gets mucked up and stuck on the pull rod. I'd remove it (pullrod, spacer, and tuning nut, check the finger for ease of travel, then reassemble it after cleaning it. Give me a call if none of that works- 760-754-2120- we should be able to sort it out-- Jim |
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Michael Hunter
From:
Traverse City, MI, USA
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Posted 1 Jun 2006 10:53 am
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| Thanks for the responses. The bellcrank seems to be tightly affixed to the crossbar, so hopefully I'll get a chance tomorrow to try your suggestion, Jim. If it's unsuccessful, you just might be hearing from me. |
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Joe McHam
From:
Houston, TX * R.I.P.
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Posted 2 Jun 2006 2:18 pm
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Couple things that comes to mind when the pull comes back sharp.. Check the return spring tension.. could be too tight..
On the puller rod.. check and make sure there is a little play in the rod. . pick the 4th string.. and rest your foot on the C pedal without engaging. If the string pulls sharp by just resting your foot on the pedal.. loosen the collar on the pull rod.. thus letting the string go back to neutral.
The other guys mention something binding in the puller finger..clean up the puller system.. and lube with proper lubrication.. CAUTION: AVOID USING WD-40.. I've seen puller systems gummed up big time using that.
Hope this is helpful. .we've owned a couple BMI's and have been there done that.. with the pulls not coming back to neutral..
Joe in Houston
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Jon Light
From:
Saugerties, NY
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Posted 2 Jun 2006 2:45 pm
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How fresh are your strings? Only reason I ask----I set up my BMI for the first time in a real long time the other day and a whole bunch of the changes were way, way flat. The amount of cranking I had to do on the nylon nuts was not natural. This guitar, when last put away was in tune. My assumption is that the ancient strings are the issue and I will be changing them before I do any more messing with the mechanicals.
FWIW.
----edited to add------
I forgot to get to my main point........if I had gone ahead and tightened the tuning nuts enough to bring the pedals up to pitch, they would have been way overtightened, as per Joe's scenario above--overtuned is the term--meaning that at open tuning (no pedals) the changer would not be at neutral rest but rather would be partially engaged. This condition makes consistent, accurate returning to pitch all but impossible.
The remedy for this situation is either to change the hole in the bellcrank and/or changer that the rods are hooked up to or, in my case, since the guitar had been in tune, check out those strings.[This message was edited by Jon Light on 02 June 2006 at 03:53 PM.] |
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Michael Hunter
From:
Traverse City, MI, USA
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Posted 4 Jun 2006 7:08 am
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| Jim - I removed, cleaned, and relubricated the pull rod per your suggestion, and success! The C pedal works great now. My only regret is that I didn't post my problem sooner. Thanks all for your suggestions. |
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