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Topic: Raise/Lower on P/P not returning to same pitch |
Wiz Feinberg
From:
Mid-Michigan, USA
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Posted 3 Aug 2005 9:22 am |
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I have a problem on my '83 Push/Pull where certain strings that I raise and lower refuse to return to the same pitch. In all cases the strings come back sharp after lowering and releasing, compared to raising and releasing. The affected strings are all plain strings, and are # 4 and 5 on E9, and # 2 and 3 on C6.
Here is what I have done to try to alleviate this problem:
- ensured that the various cross-shafts and bellcranks are not binding in any of their the mounts
- ensured that there is slack at end of back-travel, when released bellcranks return to the home position
- tightened drop springs
- lubricated moving parts
- Made sure the roller nuts move freely, in both directions
Should I remove the strings and pull out the steel bridge mounting shafts, on both necks, and have them buffed/polished? What else could cause this on a P/P?
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Bob "Wiz" Feinberg
1983 Rosewood Emmons D10 Push-Pull, with 8 pedals and 9 knee levers (Crawford Cluster), Lawrence LXR-16 pickups and aluminum necks. Nashville 400 amp with Peavey Mod. Emmons pedalbar mounted, and Goodrich LDR floor volume pedals.
I use and endorse Jagwire Strings and accessories.
Keep Steelin' but don't get caught!
Visit my Wiztunes website at: http://www.wiztunes.com/
or my main website: Wizcrafts Computer Services
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Pete Burak
From:
Portland, OR USA
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Posted 3 Aug 2005 10:12 am
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Lowers returning sharp is called "Hysteresis", and is most common on keyed guitars.
I think this is just "the nature of the beast", as they say.
Lowering causes a section of the string to move to a point behind the nut.
It will "reset" itself the next time you raise the string.
Main Entry: hys·ter·e·sis
Pronunciation: "his-t&-'rE-s&s
Function: noun
Inflected Form: plural hys·ter·e·ses /-"sEz/
1 : the lagging of a physical effect on a body behind its cause (as behind changed forces and conditions)
2 a : the influence of the previous history or treatment of a body on its subsequent response to a given force or changed condition b : the changed response of a body that results from this influence
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Nic du Toit
From:
Milnerton, Cape, South Africa
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Posted 3 Aug 2005 1:02 pm
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I've got this sneaky feeling that at some stage someone managed to 'tune' levers and pedals without understanding how the bridge fingers work on a P/P. I suggest you go to the Emmons site where you will find notes on how to correctly set up the 'fingers' before attaching any push or pull rods.
Or speak to Bobbe Seymore, he knows just about all there is to know about P/Ps.
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 Nic du Toit
1970 Rosewood P/P Emmons D10 Fatback 8x4
1980 Basket Weave P/P Emmons SD10 3x5
Peavey Session 500 unmodfied
My CD "Nightmare on Emmons Steel"
Click here to E-mail us.
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Craig A Davidson
From:
Wisconsin Rapids, Wisconsin USA
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Posted 3 Aug 2005 1:58 pm
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| Wiz,Make sure your changer is in tune first. Might be all it is. It sounds like something is still binding. |
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Wiz Feinberg
From:
Mid-Michigan, USA
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Posted 3 Aug 2005 2:53 pm
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Nic said quote:
I've got this sneaky feeling that at some stage someone managed to 'tune' levers and pedals without understanding how the bridge fingers work on a P/P.
Not in this case. I have setup many Push Pulls in my time. In fact, I recently did a complete setup on an older Push Pull, and all raises and lowers returned true to pitch.
This is probably a case of binding somewhere in the bridge pull or lower fingers, or in the main shaft itself. I had a couple of Sho~Buds that I had to install compensators on to pre-flat the offending strings, to make them return to the same pitch as when raised. I understand now that this had to do with the clearances and tension of the rivets in the OEM parts, causing bad geometry. Maybe there is a similar explanation for my bridge problem.
We shall see.
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Bob "Wiz" Feinberg
1983 Rosewood Emmons D10 Push-Pull, with 8 pedals and 9 knee levers (Crawford Cluster), Lawrence LXR-16 pickups and aluminum necks. Nashville 400 amp with Peavey Mod. Emmons pedalbar mounted, and Goodrich LDR floor volume pedals.
I use and endorse Jagwire Strings and accessories.
Keep Steelin' but don't get caught!
Visit my Wiztunes website at: http://www.wiztunes.com/
or my main website: Wizcrafts Computer Services
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Wiz Feinberg
From:
Mid-Michigan, USA
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Posted 3 Aug 2005 2:56 pm
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Craig;
Did you once have a rosewood 1983 Emmons?
Thanks for the suggestion. The bridge is in tune and it is individual fingers that are experiencing this problem, even with the rods disconnected from them. I guess I am going to have to rip her apart.
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Bob "Wiz" Feinberg
1983 Rosewood Emmons D10 Push-Pull, with 8 pedals and 9 knee levers (Crawford Cluster), Lawrence LXR-16 pickups and aluminum necks. Nashville 400 amp with Peavey Mod. Emmons pedalbar mounted, and Goodrich LDR floor volume pedals.
I use and endorse Jagwire Strings and accessories.
Keep Steelin' but don't get caught!
Visit my Wiztunes website at: http://www.wiztunes.com/
or my main website: Wizcrafts Computer Services
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Jack Stoner
From:
Kansas City, MO
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Posted 3 Aug 2005 3:18 pm
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I had to disassemble and clean the changers on my 71 PP twice. I cleaned mine with carburetor cleaner and then oiled everything and put it back together.
However, the "Hysterisis" is present in PP guitars, just like all pull's with keyed tuning heads. The worst one one my 71 PP was the C6th neck's 10th string (low C). It was very noticeable on that one. |
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Craig A Davidson
From:
Wisconsin Rapids, Wisconsin USA
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Posted 3 Aug 2005 4:26 pm
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Wiz I still have a rosewood push-pull and here in Wisconsin you have to be your own doctor. I think mine might be an 85 or it is numbered in 85. I was once told no more were actually assembled after 83, but heck I don't know. Charlie Ward from Carolina once told me about the changer. He stressed the issue while I was on the phone with him and under my guitar. Dr. Cass worked on my ax about three years ago and it has been playing great since. Hope you get things working.
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1985 Emmons push-pull,Evans SE200,Hilton pedal, Jag Wire Strings
[This message was edited by Craig A Davidson on 03 August 2005 at 05:28 PM.] |
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Kenny Forbess
From:
peckerwood point, w. tn.
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Posted 7 Aug 2005 5:39 pm
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Just a thought,
When you change strings,,
lube the nut Rollers.
Make sure to wind the strings so as to end up pulling STRAIGHT to the nut roller from the key.
pulling Off-Center from there to the Key can cause a bind ,and therefore cause a problem returning in tune ,"pulling Or lowering",momentairaly.
Kenny
[This message was edited by KENNY FORBESS on 07 August 2005 at 06:51 PM.] |
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Wiz Feinberg
From:
Mid-Michigan, USA
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Posted 7 Aug 2005 9:11 pm
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| Thanks for that suggestion Kenny. |
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Nic du Toit
From:
Milnerton, Cape, South Africa
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Posted 8 Aug 2005 11:18 am
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Wiz, It sure sounds like some binding, or a worn axle on the changer setup. I've heard it suggested that one should turn the axle, say a quarter turn. Keep us posted as to what the actual problem was.
Regards, Nic
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Nic du Toit
1970 Rosewood P/P Emmons D10 Fatback 8x4
Peavey Session 500 unmodfied
My CD "Nightmare on Emmons Steel"
Click here to E-mail us.
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Chick Donner
From:
North Ridgeville, OH USA
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Posted 8 Aug 2005 11:24 am
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| Sounds like the axle . . . it's probably all rusty. Turning it is one fix, but replacing it is probably better. It's only mild steel, and rusts badly. |
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Kenny Forbess
From:
peckerwood point, w. tn.
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Posted 8 Aug 2005 6:40 pm
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WiZ,
With all due respect to you,
I would NOT try removeing that axle if you do not have the proper tool's and know-how.
P/P changers are not as easy to dis-assemble as A/P's, you can damage lot's of parts if you're not careful.
Good luck on what ever you decide to do.
Just my 2 cents.
Kenny |
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Wiz Feinberg
From:
Mid-Michigan, USA
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Posted 19 Sep 2005 10:45 am
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I know it has been quite a while since I started this thread, but I wanted to give an update to help others who have the same problem of strings not returning to the same pitch when raised and lowered, on a push pull Emmons.
To troubleshoot this I disassembled the top of the guitar and sent the changers to Charlie Ward for rebuilding. Charlie did a magnificant job of cleaning, lubing and buffing the fingers (to a mirror finish, with no more string marks), replacing the lowering fingers that had out-of-round push holes, cleaning and rotating the axle and reassembling the changers.
When I reinstalled the bridges I clearanced everything and insured that nothing was binding, in either the raising or lowering rods and cranks. I removed the roller nuts from both keyheads and cleaned them, pulled the shafts through emory cloth, oiled them, and put them back in the keyheads, then reassembled the guitar.
After all of this work and money rebuilding the bridges nothing has changed regarding failure to return to pitch problem! Charlie says he thinks the problem must lie with the roller nuts. I have them all moving easily, without binding, and very little angular deflection behind the nuts, to the keys. I experimented by pulling the fourth string (on the E9 neck) roller nut forward with my fingers after raising string four, and it came up to the same pitch as when I lower that string. Unassisted it comes back flat. Ditto for string 3 on the C6 neck. There is simply too much friction in the nut-string-shaft combination, on certain strings, to allow them to return to the same pitch as when they are lowered and returned.
Perhaps ball bearing driven roller nuts are the answer??? Inquiring minds want to know.
Wiz
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Bob "Wiz" Feinberg
Moderator of the SGF Computers Forum
1983 Rosewood Emmons D10 Push-Pull, with 8 pedals and 9 knee levers, and Lawrence LXR-16 pickups. Nashville 400 amp with Peavey Mod.
I use and endorse Jagwire Strings and accessories.
Keep Steelin' but don't get caught!
Visit my Wiztunes website at: http://www.wiztunes.com/
or my main website: Wizcrafts Computer Services
[This message was edited by Wiz Feinberg on 19 September 2005 at 11:46 AM.] |
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Erv Niehaus
From:
Litchfield, MN, USA
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Posted 19 Sep 2005 1:30 pm
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If you are lowering a string and it comes back flat, my first thought would be that the lowering springs that lay in the bottom of the case (when turned upside down) do not have enough tension.
You need to be sure the spring is tight enough to bring the string up to pitch and then stretch the spring another 1/4".
Erv[This message was edited by Erv Niehaus on 19 September 2005 at 02:31 PM.] |
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Wiz Feinberg
From:
Mid-Michigan, USA
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Posted 19 Sep 2005 1:37 pm
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quote:
If you are lowering a string and it comes back flat, my first thought would be that the lowering springs that lay in the bottom of the case (when turned upside down) do not have enough tension.
You need to be sure the spring is tight enough to bring the string up to pitch and then stretch the spring another 1/4".
Erv
Nope. I did that and all springs are more than tight enough. Nothing is binding, neither raise nor lowering rods or springs. Also, the bridge mounting bolts and screws are as tight as possible, as are the keyhead screws. All of the raise adjusters are new teflon coated screws.
This is a roller nut problem. Has anybody out there had their roller nut rods polished or chromed to fix the detuning-on-return problem? Anyone have success fixing a roller nut tuning problem?
Wiz
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Bob "Wiz" Feinberg
Moderator of the SGF Computers Forum
1983 Rosewood Emmons D10 Push-Pull, with 8 pedals and 9 knee levers, and Lawrence LXR-16 pickups. Nashville 400 amp with Peavey Mod.
I use and endorse Jagwire Strings and accessories.
Keep Steelin' but don't get caught!
Visit my Wiztunes website at: http://www.wiztunes.com/
or my main website: Wizcrafts Computer Services
[This message was edited by Wiz Feinberg on 19 September 2005 at 02:39 PM.] |
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Pete Burak
From:
Portland, OR USA
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Posted 19 Sep 2005 3:21 pm
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How many Hertz sharp is your E string returning after lowering (assuming it started at the straight-up 440 mark on a tuner)?
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Bobby Lee
From:
Cloverdale, California, USA
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Posted 19 Sep 2005 4:12 pm
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On every guitar that I've owned, the high E string returns sharp after lowering it, compared to where it returns after raising it. This phenomenon is called hysteresis.
I have heard that it can be solved with compensator pulls. It's not easy to add those compensators to an Emmons push-pull, though.
Keyless guitars have much less hysteresis than keyed guitars. My keyless guitars show a 2 or 3 cent difference. Barely audible.
I have been told that hysteresis is caused by the length of string to the left of the roller nut. This length is very short on keyless guitars, hence the negligible hysteresis.
The problem with lowering the E string is why I switched from an Emmons p/p to a Sierra Crown Gearless in 1983. I've heard that it's also why Lloyd Green doesn't lower his 4th string.
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 Bobby Lee (a.k.a. b0b) - email: quasar@b0b.com - gigs - CDs, Open Hearts
Williams D-12 E9, C6add9, Sierra Olympic S-12 (F Diatonic)
Sierra Laptop S-8 (E6add9), Fender Stringmaster D-8 (E13, C6 or A6) My Blog |
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Bobby Boggs
From:
Upstate SC.
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Posted 19 Sep 2005 9:12 pm
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I have lower return compensators on all 3 of my Legrandes. The problem is even worse on strings lowered a full tone or more. I think they should be standard equipment on all keyed guitars.
As for the PP's. The ones I owned came back 3 to five cents sharp on 1/2 tone lowers. One can live with that. But the 10th string C6th C to A came back 10 to 12 cents sharp. Not good......... |
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Wiz Feinberg
From:
Mid-Michigan, USA
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Posted 20 Sep 2005 1:03 pm
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I'm in communication with Larry Petree about getting a custom made set of ball bearing driven replacement roller nuts. At this point it may be the only possible solution to this problem, aside from living with it, or trading in the guitar for an all pull Legrande, with pitch compensators.
I love the sound of my Push Pull, but not the tuning problems. Neither does the guitar player who stands next to me and has to hear them.
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Bob "Wiz" Feinberg
Moderator of the SGF Computers Forum
1983 Rosewood Emmons D10 Push-Pull, with 8 pedals and 9 knee levers, and Lawrence LXR-16 pickups. Nashville 400 amp with Peavey Mod.
I use and endorse Jagwire Strings and accessories.
Keep Steelin' but don't get caught!
Visit my Wiztunes website at: http://www.wiztunes.com/
or my main website: Wizcrafts Computer Services
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Wiz Feinberg
From:
Mid-Michigan, USA
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Posted 21 Sep 2005 8:53 pm
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Does anybody out there know the exact diameter of the axles used for 1983 Emmons Push Pull roller nuts?
Wiz |
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