#1
After working on my friend's strat over the weekend, we've encountered an odd problem. We've set up his 6 point tremolo so that it is flat against the body, but we can still divebomb with ease. The first problem that came up had to do with the low E string. After a dive bomb, the low E would come up sharp and read a cent over F. Giving the string a good yank, it comes back to E. That problem was solved by simply taking the string out of the tuner and rotating in the block. Re-tune and dive bomb, all is well. But here's where the goofyness begins...

After getting everything up and running, we give the G a good bend...and it goes flat. Okay...

With the G flat, give the tremolo a good dive bomb, and the string comes back up on proper pitch.

We've tried rotating the string in the block, we've checked all the string breaking points, the nut and tuner, and cannot find the cause of the problem. Change the string and the problem is still there.

We're using locking tuners as well, so it cannot be caused by the string slipping at the post...we've locked and relocked several times, we've even swapped tuners with other positions, and the problem is still there. So I'm thinking that it's localized in the bridge.

Any ideas?
#2
Ok, you seem to be quite aware of the effect of friction on the tuning of individual strings.

You say:


We've set up his 6 point tremolo so that it is flat against the body, but we can still divebomb with ease.


2 things to look at:

- when you bend a string, does it lift the bridge, even slightly, so slightly, that you can't see it but causes the springs to start compensating ?

- look at the picture of a saddle below, top view and side view.



Standard tremolo bridge saddles are designed to offer the smallest point of contact with the string when the tremolo is floating, as to offer the least friction.
That point of contact is on the top of the right end of the saddle, on the rounded off section.

Lowering the bridge flat against the body has the effect of tilting the saddle by lowering the left side of the saddle on the side view

The consequence is that the point of contact between the string and the saddle moves to the right, along the rounding, and eventually beyond where the rounding eases off, and onto to the flat edge at the extreme right end of the saddle. This has the effect of increasing tenfold the surface of contact between the string and the saddle, increasing by as much the friction and the chances of going out of tune. Eventually, you can try putting a drop of oil on the point of contact between the string and the saddle.

If you don't understand what I mean, look at this telecaster saddle:


Notice that the saddle is in fact a whole cylinder. Whatever the angle of the bridge on which the saddle is mounted, the point of contact between the string and the saddle never finds a flat surface that will increase the friction.

Now if you have the modern saddles...

like the vintage strat saddles, you can tilt the saddle only so much before the string starts making contact with the flat front side of the saddle. It's even worse with the modern saddle because of the sharp edge between the rounding and the flat front side. If a string makes contact with that edge, you increase string breakage, and greatly increase friction and going out of tune, as the edge gets caught in between the wounds of wounded strings.

Eventually you'd might like to try out a set of ferraglide saddles:



all depending of course on the tilt angle of your saddles when you tighten the rear of the bridge flat against the body.
Last edited by ColdGin at Feb 21, 2007,
#3
Thanks for the detailed response...

No, the bridge does not move when the string is bent. The bridge doesn't really move unless you do something extreme, like pick up the guitar by the low E or something. Even so, we blocked it for testing anyway.

This didn't become a problem until he started using the tremolo. Until that point, the strings remained in tune even after bends. It's an odd problem.

I'm a little more inclined to think the problem is happening somewhere in the block or at the bridge plate. The reason I think this is from some experiments we were doing to try and figure out the problem.

Here's what we did.

1. Bend the G up a full step at the fifth fret. Let go of the bend and check tuning. String is registering F#, nearly perfectly, but flat by a half cent to a full cent.

2. Leave the bridge in place, but tune the string back up to pitch using the tuner. Note that the string is back at G.

3. Dive bomb the bridge. Check tuning. String registers G#with the same variation as step 1.

I could maybe see that the initial break point over the saddle could be a major friction point, but enough so to bind the string up enough where the addition of a little more tension would pull it out? And even then, shouldn't that tension be present when we tune the string back up to pitch and dive bomb again? I think that would keep the string from going sharp. But it's funny, we can bend, go flat, retune, bend, go flat, retune until the cows come home, but bomb the bridge, and it always goes up in pitch almost exactly a half step.

The saddles are the vintage bent steel style, but I'm trying to convince him to buy some graphite saddles. I've never liked how much those bent steel saddles move around, even without trem use.
#4
No friction at the nut ?

Have you also checked if tightening the bridge flat didn't pull the bridge sideways, causing strings to angle at the nut ?

Try replacing the G string with another B string and see if the problem is still there. If not, the nutslot for the G string might be too tight.
Last edited by ColdGin at Feb 21, 2007,
#6
Quote by ColdGin
oops


No harm, no foul. Thanks for posting anyway. Really, any ideas would really help. I think I've covered all of the common angles on this one. The only thing I can think of to try next is replace saddles with graphite units or try an entirely different bridge. The saddle situation is odd...I'm thinking if was a problem with the break angle over the saddle, then why only the G string? I would think something similar would occur in another string, even to a very minute degree. Blargh!!! SAVE ME LEO FENDER!!!
#7
Hello, first post here.

It's my guitar TwoString has been talking about. Let me give the best descriiption of the problem I can.

First, I'm an EVH fan, and that was the reason for locking tuners. I wanted to start doing some dive bombs, and be able to keep guitar in tune. This has actually woked great. As TwoString described, I have the Bridge Set Flat against the body, and adjusted the springs so there is greater tension on the Low E side. This has stableized the tuning pretty well. I can hit the wammy as far down, as fast, and as hard and as often as I like, and it stays in perfect tune. It's great.

The problem is with the G string, and ONLY the G string. If I bend it over a full step, it goes flat about a half step. That's not the strange part. It goes back into perfect tune after a dive bomb. I'm 99% sure it's not the new locking tuner. If it was, why does it go BACK IN TUNE after Dive Bombing the Bridge? I don't think there would be anything Pushing the string Back IN the Tuner...

Also, if I do the bend on the G string, goes flat. Leave the bridge alone, and retune the D string with the tuner. Then Dive bome, it comes back Sharp. Retune, Dive bomb again, stays in tune until I do another bend on the G string.

It's also possible the problem already existed, but I just didn't NOTICE the problem until after installing the locking tuners.

Now, here's what we've done so far for troubleshooting..

New Strings - tried with the old string as well.

Put some pencil lead in the nut groove.

took an old D string, and ran that through the groove pretty vigorously to smooth any rough edges.

Set the bridge screws so ONLY the 2 outside screws are holding the bridge in place. Set just right so the bridge is flat against body when screws barely start to make contact.

Swapped the G Saddle With the D saddle - problem still exists on G string.

I put some oil on the contact points. Saddle, Bridge Screws & holes.

Waiting on new set of bridge screws.


Don't know what else to do.

Thanks.
#8
You know all, after re-reading over a few times what you write and I really think the problem lies with ... the friction of the tail of the bridge with the body, and the difference of tension in the springs.

To notice this the best point of observation is from the bottom edge of the guitar, nose on the strap button, eyes just above the flat top of the body, looking in direction of the neck

First there is a huge surface of contact between the bridge and the body. And everytime you lift the bridge from the body, between the moment you start pushing the bar until the point where the bridge does not touch the body anymore, there is friction, and in 2 directions. !

Second, having a tighter spring on the side of the bridge where the low E lies is absolutely normal to compensate for the higher tension the low E needs to be correctly tuned. But, this extra tension causes the bridge to lift first from the body on the high E side.

Third, the bar is located on the high E side, which increases the lift force on the high E side when the bar is pushed.

The fact that both sides of the trem bridge don't lift off from the body at the same time when pushing the bar suggests a warping force until the trem bridge has completely lost contact with the surface of the body, at which point the trem has found a balance between the pull of the strings, the pull of the springs, and the push on the bar, at which point, both sides of the trem, the right and the left, move again both with the same amount of displacement when more pressure is exercized on the bar.

The presence of a twisting force at lift off of the bridge implies that, even though the rear of the bridge appears to be in contact with the body, there is enough friction to prevent the bridge from falling exactly in the same position when releasing the bar, and staying in exactly that position after strings like the G are bent.

Unfortunately, apart from fine-tuning the springs, the fender vintage tremolo is really not designed to be set up flat againt the body. The fact that it is designed to float is precisely to allow the whole assembly, including the springs and the strings to reach a point of balance, where all the active/reactive forces cancel out, which is the guarantee that the trem will, theoretically, with the least friction involved, always fall back in the same position when pressure on the bar is released.
Last edited by ColdGin at Feb 23, 2007,
#9
Great idea ColdGin...but the spring setup on the guitar was set to counteract the tension of the strings. The way Jon had the guitar set up, the springs were set like this...

X=Spring Attached
O=No Spring

Claw Block
Low E Side
X X
X X
O O
O O
O O
X X
High E Side

This actually seemed to keep the bridge from twisting when used. I did something similar on my 63 Reissue Strat, and I have absolutely NO problems with tuning (although, my bridge is floating)

Claw Block
Low E Side
X X
X X
O O
O O
X O
O X
High E Side

There's a thread somewhere on this forum with pictures of this setup. Unless Jon has changed things a bit (and I'm sure he has, the new bridge screws came in today), the claw was at a slight tilt - tighter on the bass side than the treble. And the contact points between the bridge and the body are quite odd. First, the bridge doesn't make solid contact at the rear of the bridge...it seems the bridge design or body fluctuations make this impossible. The bridge makes contact (when viewing the guitar with end pen down and headstock up) on the lower left corner and on the right side only. The entire middle area seems to not contact the body, and no amount of tightening can make this happen...it seems to be where the bridge is bent to form the rear saddle-screw mounts. Also, the route in the body seems to be a bit wide on the bass side, so the bridge doesn't make solid contact here. I can't say anything about the pickguard side of the bridge because the pickguard is in the way.

I'm sure Jon is probably working on it right now...I'll wait until he gets his say on the situation. But still, thanks a lot ColdGin, you've really been the only one helping us with this odd problem.
#10
Sorry TwoString, GoldGin was right. Putting the springs back to factory setup seems to have solved the problem

Like you said, it was setup as

Low E Side
XX - Higher Tension
XX
00
00
XX - Lower Tension

But when I swithed it back to

XX - Equal Tension
00
XX
00
XX - Equal Tension

The problem is gone..

I did keep high tension on the springs (but equal tension accross the bridge) to keep the bridge ALMOST flat to the body, just ever so slightly floating.

And believe it or not, it still stays in tune after a dive bomb. That is probably thanks to the Locking Tuners, What I bought them for in the first place. And the G string no longer goes flat after bending it. I'll probably eventually get some Graphite saddles too.

I guess this goes to prove that guitars are like people. Every guitar is different. Even 2 identicle guitars made at the same factory, by the same person. What works on one guitar, may not work on the next.

Just a side note TwoString
The new bridge screws did fix the popping that was happening with the dive bomb.

2001 Ernie Ball Music Man Axis Super Sport
2001 MIM Standard Strat
Peavey Classic 30 112 Combo.
My Gear
Last edited by jonmo1 at Feb 23, 2007,
#11
One last observation, I notice that your spring layout is distributed on the sides, lacking springs in the middle slots. This has the effect of increasing, hold tight, the friction of the spring pins of the outer springs in the holes of the trem block as the warping force the outer springs have to compensate increases, compared to a layout with springs in the center positions.

It is a lot more efficient, to reduce this friction, to have most of the string tension balanced out by the center springs, leaving the outer strings to compensate mostly for the difference of string tension between the high E side of strings and the low E side of strings, rather than having the outer springs to compensate for more.

This is a proven fact by the usage of the tremsetter, one of it's main characteristics being a re-distribution of the overall string tension with an increased share to be compensated by the center spring, the tremsetter itself, and subsequently, a lighter load on the edge springs and less friction on the spring pins.

I'm not sure if the tremsetter can work in a flat-blocked trem configuration, but it can be set up and will work with a floating configuration, set up as to leave the least pull movement.
Last edited by ColdGin at Feb 23, 2007,
#12
Quote by jonmo1
Hello, first post here.

First, I'm an EVH fan...


Guess that with me, that makes 2 of 'em on this board.
#13
Glad to hear that the screws stopped that problem...either way, as long as the blasted problem is fixed!! Dive bomb away...jam again soon? hehehe

Quote by ColdGin
One last observation, I notice that your spring layout is distributed on the sides, lacking springs in the middle slots. This has the effect of increasing, hold tight, the friction of the spring pins of the outer springs in the holes of the trem block as the warping force the outer springs have to compensate increases, compared to a layout with springs in the center positions.

It is a lot more efficient, to reduce this friction, to have most of the string tension balanced out by the center springs, leaving the outer strings to compensate mostly for the difference of string tension between the high E side of strings and the low E side of strings, rather than having the outer springs to compensate for more.

This is a proven fact by the usage of the tremsetter, one of it's main characteristics being a re-distribution of the overall string tension with an increased share to be compensated by the center spring, the tremsetter itself, and subsequently, a lighter load on the edge springs and less friction on the spring pins.

I'm not sure if the tremsetter can work in a flat-blocked trem configuration, but it can be set up and will work with a floating configuration, set up as to leave the least pull movement.


As far as my spring layout, my bridge didn't stay in tune until I arranged the springs that way. I had the typicsl 1/3/5 spring distro and it fell out of tune and didn't pull back to the same spot after trem work. I angled the claw with more tension on the bass side, and it got a little better, but still didn't stay in tune. Then I moved the middle spring up one space on the claw and block, and I got closer, but for some reason, I couldn't balance it out...the treble strings were staying flat and the bass was going sharp. So that's when I angled the treble side spring the way I did, and everything just LOCKED in perfectly without any additional tweaking with the claw. It has been that way for 7 weeks or so at this point with the same strings, and the entire system is still balanced and staying in tune. Blasted touchy guitars!!!

The tremsetter could work maybe if we use that as the resting point for the bridge instead of the body top. It would technically "float" just a bit but it wouldn't have any pull-up, right? Sounds like a theory to try, but spending money on a trem setter that may or may not work doesn't sound like a great idea.

This has truely been a learning experience...after years off from guitar tweaking, it's great to have spent the last 2 months or so really getting back into the act of screwing around with stuff. Thanks Jon and ColdGin!