Which Locking Nut do I need?

[KeeperOS]

A couple of days ago I bought a new guitar with a Floyd copy.
(The manufacturer says it's built with the Schaller Floyd Rose dimensions).
(THIS one)
Here's something funny. The cheap Floyd copy is so good as to keep perfect tuning after whammy abuse when the nut isn't locked.
On the other hand when I DO lock the nut the guitar goes insanely out of tune even with moderate vibrato, particularly the "D" string.

I was planning to replace it anyway (although I was hoping it would be later rather than sooner) so here's the thing.

I want to get it the Gotoh Floyd Rose which from what I read comes with the 1 5/8 nut which I'm SURE is not the right one:
Radius: 400 mm (16 inches)
Number of Frets: 24
Fret Size: Jumbo (2.9 mm)
Scale Length: 648 mm(25.5 inches)
Nut Width: 43 mm

Is anybody SURE exactly which nut I need?
Also, would it be a good idea to FIRST get a new nut and then replace the bridge if needed or will I just be paying for the nut twice?

 

[WhoFan]

Re: Which Locking Nut do I need?

first thing is measure the nut width... 1 11/16th and 1 5/8ths are the 2 most common widths... 1 11/16th size is an R4, a 1 58th is an R2 I'm not sure what 43mm is but i can look it up

most Schaller and Original Floyd style nuts are for 10 or 12 inch radius boards... not 16 inch radius like a fair bit of the cheaper copies are...

the height of the nut is the other problem... most cheaper Floyd Copy nuts are not as tall as a real Floyd nut... you may have to do some custom work to get it to fit...

on some of the cheaper nuts they use 2 wood screws to hold it to the neck... they can work fine but some tuning issues i've had in the past with this style is the nut shifting during trem use...

another major sorce of tuning issues i had on my cheaper Jacksons was the Floyd posts... they were awful when they were brand new... too sloppy of a thread to them and they rocked in the breeze!!! I changed the studs and inserts to hardened ones from Stewmac

 

[WhoFan]

Re: Which Locking Nut do I need?

43mm looks like it will be an R4 nut width...

 

[KeeperOS]

Re: Which Locking Nut do I need?

Here's something interesting:
Google says this:
43 millimeters = 1.69291339 inches
1 11/16 inches = 1,6875 inches = 42.8625 millimeters.

However my own measurements (with a common paper ruler) say that it's just a hair LESS than 42mm which incidentally fits like a glove to the 1.65 inches width (= 41.91 mm) which in turn almost fits to the "SpeedLoader Nut #7: 17" radius (431.8mm), Neck Width 1.65""

The nut is top mount and for sure it's mounted on two wood screws.
I see no shims under the nut.
The nut is 2mm thick in the lower part (towards the headstock) and 5mm thick in the higher one towards the bridge, both measuring from the back of the nut up to the point where the string contacts with the nut surface.
(Do note that when measuring I measured from surface to surface, NOT the elongated parts that serve as string spacers!)
Also it's 15mm "long" (if the 42mm is the "width" and the 2mm/5mm are the "height")

So the dimensions the way I measure them are 41.91mm x 15mm x 2mm/5mm...

So, with all these what in your opinion would be the most sensible course of action?

 

[threechordcharlie]

Re: Which Locking Nut do I need?

none

 

[WhoFan]

Re: Which Locking Nut do I need?

i think you may need something better then a paper ruler to make a good measurment but it may do the trick... sometimes during manufacturing they do sand a little too much off a neck... i have one strat neck that is sopposed to be 1 11/16th but it is really 1 10/16ths which does make a difference with my FRO i tried to install on it

if you remove the nut it may have the size on the bottom...

 

[Extant]

Re: Which Locking Nut do I need?

Warning. The Gotoh Floyd Rose won't fit because it's built to the OFR dimensions - it has long locking bolts in the back as opposed to the thick short Schaller-style ones. So you won't be able to pull up unless you can find short, thin locking bolts that you can replace the original ones with.

 

[Ayrton]

Re: Which Locking Nut do I need?

Before you go through all that, make sure the string tree is screwed down far enough. If the guitar goes out of tune when you tighten the lock pads, the tree is to high.

 

[KeeperOS]

Re: Which Locking Nut do I need?

...if you remove the nut it may have the size on the bottom...

Well, I measured the nut's width but I think this method would be best.

Warning. The Gotoh Floyd Rose won't fit because it's built to the OFR dimensions - it has long locking bolts in the back as opposed to the thick short Schaller-style ones. So you won't be able to pull up unless you can find short, thin locking bolts that you can replace the original ones with.

Yeah, the guys had already informed me of this. I measure that there is a gap about 8mm from the end of the bolt that's the closest to the route. I think this should be enough no? If not I'll either try to replace the bolts like you said or maybe enlarge the route just a tad. I sure am not gonna go and buy the Schaller that costs about 100$ more when it's the Gotoh I like the best anyway...

Before you go through all that, make sure the string tree is screwed down far enough. If the guitar goes out of tune when you tighten the lock pads, the tree is to high.

DING DING DING, we have a winner!!!

Heheh, it seems all the the screws that were used in that guitar were made of the worst kind of iron or sth they could find.
ALL of them are completely covered in rust.
THAT however easily allowed me to tell that the string tree in fact WASN'T returned to its' previous position after the setup!
I screwed it down until the part that the screw had rust, tuned the strings just a tad too sharp to increase tension before locking and lo and behold: it now holds it's tuning MUCH better!!! (it's still not 100% there but I'm starting to think it also has to do with properly tuning it too...)

Thanks you guys for coming to the rescue!!!

I'm still gonna replace it though, although it now works fine I just can't stand how cheap this metal looks/feels, plus, I kinda suspect it also negatively affects the sound as well...

So, is there a GOOD nut (preferably Gotoh) that's for a fretboard with a 16" radius? Either for 1 11/16 or 1.65 inches width.
(BTW which string spacing I have?
The distance between the low E and the A string is EXACTLY 7,5mm, center to center while from the D to the G it's EXACTLY 7mm again center to center...)

 

[octavedoctor]

Re: Which Locking Nut do I need?

Most likely cause of the guitar going out of tune is that the nut clamp itself is loose. With the clamp unlocked the strings are free(ish) to slide so only tuner or wrap instability could affect them. However if the nut clamp is not securely bolted then it will slide as soon as it comes off load under the action of the headstock harp. This would cause the extreme lack of stability you are experiencing, so the nut doesn't necessarily need replacing but you may need to have it checked out.

 

[KeeperOS]

Re: Which Locking Nut do I need?

By clamp you mean the 3 metal plates that are screwed by the hex bolts right? (sorry if that's a silly question)
It might be, I screw it until I feel it tighten and stop in fear of over-tightening and stripping the bolts...

Honestly only replacing the clamps and/or bolts and keeping the nut would probably be the best scenario.

On a different question, Gotoh says that the saddles of the Gotoh GE-1996 have these heights (in mm):
Strings 1 and 6 - 9.2
Strings 2 and 5 - 9.8
Strings 3 and 4 - 10.2.
What radius does this translate to?
Is there a way to somehow set the saddle height to match the fretboard's radius?

 

[octavedoctor]

Re: Which Locking Nut do I need?

The nut clamp is the correct technical term for what you call the locking nut so i'm referring to the whole unit.
On older Floyd units the whole assembly is held to the neck with two cap head bolts going through the neck. If these are loose, or the nut is shimmed with smooth brass shims then the nut clamp can slide microscopically when the strings come off-load because the headstock "harp" (the collection of strings behind the nut) is still under tension and can exert sufficient pull on the nut to shift it, causing the sounding length of each string to settle back into a different pitch, usually slightly sharp on some strings, flat on others. This can't happen if the nut clamp is not locked down!

If this is what is happening (and i honestly can't think of anything else that would cause the symptoms you describe) then replacing the nut isn't necessary, you only have to make sure that the one you have is fitted properly.

 

[KeeperOS]

Re: Which Locking Nut do I need?

Dunno, the nut is surface mount by two wood screws and, like all the other screws in that guitar, rusted at that...
Also as far as I can tell there is no shim under the nut (it would show from the side wouldn't it?).

The only string that is actually going completely off tune (I'm talking an entire half-tone+ down) is the D although it could be that the others are also going a tad more flat/sharp but I'm not noticing it because of the sheer difference of the D.

So what's the proper procedure for this?

 

[WhoFan]

Re: Which Locking Nut do I need?

on my Jacksons they have a tilt back headstock and i still have to clamp the string retainer bar down quite a bit... or strings go sharp when i clamp the nut down...

 

[KeeperOS]

Re: Which Locking Nut do I need?

Yeah, mine is tilt back as well.
After I clamped it down almost to the point where the low E was touching the wood (I left a space about the thickness of a D string) it improved which also seems to make sense with what octavedoctor said.

The bar changes the angle of the string tension from sideways to downward both minimizing the sideways pull AND increasing the downward hold.
Still, if the nut was completely secured at the neck then there wouldn't be a need for that.
In short it seems like a contigency measure to make up for crappy tolerances...