A method for decreasing detune due to cabinet flex

[Jerry Overstreet]

If a center brace can minimize this effect, has any builder tried attaching the center rail to the end plates?

Many steel guitars have a center rail, Emmons, Sierra, Derby, pre G2 Mullen etc., so it would seem like a simple matter to tie it to the endplates and guitar body ends if it would stiffen the body and make for less deflection if, in fact, it works.

[Bob Hamilton]

Doesn't seem to affect the knee at all, as far as I can tell, Tim. I lubed it up well though. The truss just kind of lifts the center of the cabinet and stiffens it up a bit. The closer you can get the upward pressure to the center of the cabinet the better, obviously, but even toward the ends it helps. Before I started using this method, I tried actuating the changer without using the floor pedals, there was still drop. The same drop numbers as with the pedals, so that was out. Then I used the clamps and I still had drop. This was the method that solved my problems, but every guitar is different. Loose keys, keyhead screws, endplate screws, etc. You really need to look at the entire instrument and you can get a couple of cents here and a couple there. Tune out the rest and go play....

[Tim Heidner]

Well, I fixed those end plate screws and tightened everything up but it didn't help any, I still have around 13 cents of drop on the 6th string using the A+F or the C pedal. I think this guitar was made with undersized lumber in order to keep the weight down.
I was wondering if a board or plate attached across the bottom with cutouts for pedal rods and levers would make any difference.

[Bob Hamilton]

Is it just the sixth string?

[Tim Heidner]

There's a little bit of drop on other strings, but the 6th is the major problem. I put a compensator rod on it, but that made the 5th string have a problem.
It's playable, but it's kind of annoying.

[Bob Hamilton]

Hi Tim. I think I'd start with the keyhead and nut.

[C Dixon]

Jack I had the impression the Emmons counter force mechanism used pedal actuation energy to counter detune. I had been told it stiffens the feel of the pedal action undesirably. Perhaps this is hearsay.
Can anyone else comment?

Interesting you should ask Jim. I am presently working on a LeGrande III, (1st one I have ever worked on), and I am dissapointed to say that the A, B and C pedals are stiffer than any LeGrande II I ever worked on, and/or played.

However, this may not all be due to the "counterforce ass'y", as I have just verified that the pull rods are NOT in the standard factory set up holes; at least on the B pedal. I am going to check them all now to see.

IF the counterforce mod causes ANY stiffer pedal action, it negates what I was told adamately by Ron Lashley Sr, when the option first became available. And something I believed was true.

I would be very saddened indeed, if something so highly taughted and pricey would cause a pedal to be noticably stiffer.

Oh well.

On another note, every time I have read posts on this subject over the years on this forum, I see comments that "cabinet drop" is not a major issue, or words to that affect. In several cases in the past, I have even read that it was "imagined" or words to that affect.

I can only comment and I mean NO dissrespect, that IF it is not of major concern and/or it is imagined, then I must conclude that there has been an unecessary and incredible number of "major" non-ending discussions about something that is not of major concern, or am I "imagining" something?

If'n ya get me drift

May Jesus right ALL wrongs,

c.

[Rich Peterson]

Good to see you posting again, Carl. Your comment on the Emmons prompted this question.

If the cabinet flexes when strings are raised, because of increased tension, those raises have to compensate for the drop in addition to the desired pitch change. A well engineered counterforce would prevent the cabinet flex, so less force would be required to get the desired pitch. If the counterforce mechanism is as efficient as the changer, pedal force would be unchanged. But I'm not an engineer, so I'm asking if my thoughts are awry.

[C Dixon]

Good to see you posting again, Carl. Your comment on the Emmons prompted this question.

If the cabinet flexes when strings are raised, because of increased tension, those raises have to compensate for the drop in addition to the desired pitch change. A well engineered counterforce would prevent the cabinet flex, so less force would be required to get the desired pitch. If the counterforce mechanism is as efficient as the changer, pedal force would be unchanged. But I'm not an engineer, so I'm asking if my thoughts are awry.

TY Rich,

Well, IF the counterforce did not work as it does, your "question" AND thinking would be very logical. However, once you study how it works, you will see how likely it is that there will be some increased tension, even considering the factors you elloquently presented.

In a word, LeGrandes (and I believe Remington's and Zum's) counterforce ass'y literally push against something that is fixed; similar to a person pushing against a pole or wall.






But the ratio is about "20 to 1". So the theory is, "ya don' feel it". I bought into this, but now I am not so sure.

It is worthy to note, that Mitsuo is coming up with a NON counterforce adaptor that does NOT do the above. Rather, it actually pulls given changer fingers a tiny amount AT the changer end.

IE: if the 4th and 6th strings drop when say the A pedal is engaged, tiny adjustable threaded screws push against those changer fingers to raise (or lower) them back to pitch.

Note the very small holes in the right end plate towards the bottom in the picture below: These holes contain RAISE and LOWER adjusting screws for each string. These set screws can be adjusted for not only cabinet "drop" but also cabinet "raise", if necessary. I know of NO former PSG that has ever addressed cabinet raise. Clever indeed.






According to Mitsuo, you can not feel it. The jury is still out on that however,

Thanks again friend,

c.

[Rich Peterson]

TY Carl

Now I understand. The "counterforce" is misleading, as is counters the detuning by shortening string length; not by applying force to counter the cabinet flex.

The mechanical solutions are interesting, but I think more can be done to strengthen the frame and cabinet. In particular, I'd be interested in the effect of carbon fiber bars inlaid into the wood. Do the MSA Millenium guitars have significant cabinet flex?

[C Dixon]

TY Carl

Now I understand. The "counterforce" is misleading, as is counters the detuning by shortening string length; not by applying force to counter the cabinet flex.

The mechanical solutions are interesting, but I think more can be done to strengthen the frame and cabinet. In particular, I'd be interested in the effect of carbon fiber bars inlaid into the wood. Do the MSA Millenium guitars have significant cabinet flex?

Rich,

I don't know, but I will say this: A very famous player (whose name is being with held for obvious reasons) told me that there is cabinet drop on his MSA Millinium. So take it for what it's worth.

It is interesting to note that the Fender 400's/1,000's/800's and 2,000's did not have cabinet drop. 'Course they weighed a ton also , because of their massive and rigidly fortified aluminum "Wrap-Around" frames.

Cabinet Drop is dismissed by some, but I assure you that for most, it is a major problem, lest Emmons and others would not have come up with a supposed cure.

I, for one, cannot stand the 6th string (as an example) dropping when the A pedal is engaged; especially when you add the F knee lever. There are "greats" who feel exactly the same. Plus, they have tried various and sundry ways of solving it.

Musically cultured ears can hear things the less cultured can't hear. Bless their hearts. Who knows, just maybe the less cultured are the more blessed. Whatcha thank?

c.

[Earnest Bovine]

Here's my hypothesis: Once the top of a PSG is bowed it gets progressively easier to bow it further by increasing the tension of a string.

The hypothesis is intriguing and plausible. It seems easy to test it, so I did. While changing strings I first removed several strings, leaving the G# and B strings, as well as the low E (.054).
In this condition the cabinet is less bowed.
Cabinet drop on the low E (.054), from mashing the A+B pedals, was the same as it was with all strings on the guitar.
I conclude that your hypothesis does not apply on this guitar (Zum). However it is still worth testing on other guitars.

[b0b]

D-10 guitars have measurably less cabinet drop than S-10 guitars. Why is that?

[Jim Pitman]

Interesting Ernest (Doug).
I have done the exact same test on my Fessey and it does support the hypothesis.
Wow! there may be more than a couple of means by which cabinet detune makes itself apparent.
BTW, I recall you and I running around the St Louis Convention floor in about 1984 measureing cabinet drop on various manufacturer's pedal steels.