Return compensators

[steeljanne]

I have built several E9 pedal steel guitars, all with a bit of tuning problem at the 4;th string, rise ok but when lowering it return sharp, has anyone out there a pic or drawing of a compensate mech .

[Bent]

Janne, I believe there to be more than one of those out there. I would love to read details and explanations of these as well. Anyone?

[richard37066]

You may - or may not - have stated your problem accurately. Why does this effect occur only on the 4th string and on "several" instruments? If a compensator is required for all instances then it points to a much more basic problem.

Bent has posted his procedure for adjusting the lower return springs - that is - if a raise tends to pull the lower finger away from the stop, then it is too loose. Bent - and I - adjust it such that it barely moves when a raise is effected - then crank in another partial turn of the screw until it disappears altogether. This may - or may not - be a part of the problem. When "tweaking" things, the "tweaker" needs the patience of Job.

[Bent]

Richard I'm not sure that what you write is the problem here. I think what Janne is writing about is string hysterisis, where, especially the 4th string lower returns sharp after the lowering. I believe this to be a separate issue from lower return spring tightness.
I just discussed this with Ben, the guy who has 004 and was just here for adjustments and additions on his steel.

After thinking on this, and reading, I am starting to believe it goes like this: Imagine, exaggerated, when the finger pivots to lower the string, said string gets a different contact point somewhere in back of the original contact point. Upon returning, the finger "picks up" the string on this new point. Then, upon returning to the start it will pull the string up to open tuning - but will pull it too far and there is your "returning sharp" phenomenon.
I know one builder uses a small rubber O ring, another uses a very short length of spring in the changer to alleviate the sharp. I don't quite know HOW they use it, nor do I know if these ideas are patented or not.

Don't ask me why this thing rears its ugly head on the 4th string only. Does it have to do with string diameter and tension being in just the "right" spot...? Dunno

[richard37066]

Bent -

You're probably right, in hindsight, on the return spring thing.

However, I can't imagine a "hitch-in-the-gitalong" on the finger. For starters, I'm absolutely certain that your fingers are a near-perfect circle. (As near perfect as the TOS will allow) Secondly, and in viewing your photos, the fingers are polished to the extent that the string is not impeded as it "slips" back to its original position. That is, the string is shortened in effecting a lower. As it returns to the static position, it must slip just a tad on the finger as the tension and length is increased. I can't see anything deleterious like this happening on any of your instruments.

Has anyone questioned string diameter? What about the different types of "wrap" at the end? Is the free end of the wrap digging into the finger? MOST CONFUSING!

And I ain't got a reasonable answer.

What's also confusing is that I've never experienced this phenomenon on either the GFI or on the Dekley. Why on some instruments and not on another? Somebody please educate me just in case I run into this on my second refurb of the Dekley.

Richard

[richard37066]

Bent -

Have we both missed something? Janne states that "rise OK but when lowering it return sharp". Does he mean that he executes a "raise" and that it doesn't return true but stops just short - returning "sharp"?

[steeljanne]

Maybe I found the answer to how the compensator works; http://steelguitarforum.com/Forum5/HTML/012682.html
The compensator was invented by Franklin Sr. Paul Franklin has on almost every string that has rise/low.
Strings 4 and 8 returns sharp with 1 cent on my guitar , nothing on the 2:nd .

[na4it]

After reading the description of the O-ring deal on the other forum, I can see how a tuning nut could slip to the top of bottom of the hole, and return in a different location, until it snaps back into it's proper place.

Below is a rudimentary picture to explain. I did in fact see this on the Marlen I had. At rest, the pull rod is "centered" and when pulled, it moves upward, and for some reason, the nut cause it to "hang" there. I had actually heard a slight "pop" when my Marlen did it. I should mention it stopped when I put on a new tuning nut.

comp.jpg (8.27 KiB) Viewed 3441 times

Just thoughts from N O V I C E!

[Bent]

Bent -

Have we both missed something? Janne states that "rise OK but when lowering it return sharp". Does he mean that he executes a "raise" and that it doesn't return true but stops just short - returning "sharp"?

Richard, I didn't miss anything. But what you are talking about re the lower return spring and tightening it up sufficiently is correct but a different animal.
True again, so far I have not had any complaints about the hysterisis thing on my guitars. That doesn't mean that it isn't there, maybe only that it is so minuscule as to not bother the player. I am sure you have read about hysterisis? Until I see something different, I believe what I say to be a sound explanation.
It could be that the reason my changer is not plagued by this is because my fingers are 1" diameter, not the usual 3/4". They are round to the nth degree, yes, but polish might leave something to be desired. They come off the mill in a finished condition and after that get a sandpaper treatment by the shoeshine method with 400 and 600 grit. Been thinking about rigging up some buffer type in the mill for buffing with compound like I do the aluminum.

As to the wrap digging in - no I don't believe so. We try to install the string ball hookup so that the wrap ends before the radius starts on the finger.

[Georg]

What's also confusing is that I've never experienced this phenomenon on either the GFI or on the Dekley. Why on some instruments and not on another? Somebody please educate me just in case I run into this on my second refurb of the Dekley.

Richard,
My GFI Ultra show hysteresis problems - when bought (used) to the extent that I almost trashed and burned it. BUT, that instrument has a solid bar instead of keyhead rollers and is "keyless", so can to some degree be "excused" as a design-flaw.

My other PSGs - MSA Uni, CarpSteel & 2 Dekley - also show slight hysteresis tendencies, but not to the extent that it bothers me - not audible while playing as it disappears in the constant intonation-adjustments I do with the bar anyway. These PSGs all have regular rollers and keyhead mechanisms, which when properly cleaned, adjusted and oiled minimizes the "hang/slip" tendencies at that end.

In addition to "hang/slip" - pretty audible and testable on my GFI Ultra, strings in themselves need time to settle perfectly at pitch when, and after, they have been tensioned or slackened. Some string brands/makes "pitches in/out" quite audible when tension changes, while others stabilize to pitch too quickly to notice the effect. Most PSG strings should be "rigid" enough to make this "settling effect" go unnoticed.

The "O-ring bumpers" mentioned pretty much reduce hysteresis in strings and what's caused by "hang/slip" to nothing by bouncing and easing the string back to neutral after lowering, when O-ring rubber is fresh and it is adjusted just right to meet the lowering finger "a hair-width or so" before the solid return-stop.

You should not have any real problems with hysteresis on the Dekley when all is cleaned up and moving freely. It takes up some of the "back bounce" in the mount of the return stop plate, doing some of the same "bouncing and easing back to neutral" as O-rings on Franklin PSGs do only to a lesser and non-adjustable way.

For my own project I am designing-in adjustable "rubber bumpers" in the return stop plate itself. Tested and found to work just as good as O-rings on rods, and will probably last much longer.