Scale length--Neck swap question

[DalyTek]

OK, I have a question.
I was wondering if I took the neck off my 1990 Fusion PRO and stuck it on my KE3 body if it would intonate and if there would be any problems?

Both guitars are completely assembled right now, so I have not tried anything. The only thing I did was attempt to measure from the end of the neck heel (without removing the neck) to the start of the Floyd Rose, and both seem to be the same distance, leading me to think the bodies are not made to a specific scale length, but rather that is all in the neck. Anyone tried this? What results have been seen?

If I could put this neck on my KE3 body, would I then essentially have a 24.75" scale Kelly? I love this Kelly body, and the Fusion neck is amazing, so I wanted to see if I could merge the best parts of each and get one uber-Kelly.

[moku]

both would have to be 24-3/4 scale in order to work... that is, work without modification (which is a bitch and i would try to avoid that).

[84sups]

It will not intonate if you do a neck swap.

[Newc]

Does the Kelly have a 24 fret neck? If so, it will work just fine. I put a USA Fusion neck on a WR body and it worked just fine.

[moku]

um... scale has nothing to do with the number of frets...

[DonP]

The second Jackson I ever bought was a KE3 with a Fusion PRO neck.

It worked fine. I say that in the past tense because the pawn shop didn't have a case and just wrapped the guitar in cardboard. The neck survived but the body lost a huge chunk in shipping, and I got a 50% refund but eventually sold it. While I had it it played great and intonated fine.

I eventually mated the PRO neck to a Red Fusion Deluxe body.

The rule of thumb with Jackson necks is 24 necks with 24 fret bodies, and 22 fret necks (never seen a 22 fret short scale neck however) with 22 fret neck bodies.

[Newc]

um... scale has nothing to do with the number of frets...

Au contraire, mon frer. A 22 fret neck is shorter than a 24 fret neck, at least when done correctly - those Warmoth abominations don't count, because they were not done correctly (i.e. extending the board only).

You cannot intonate a 25.5" scale 22 fret Jackson neck on a Jackson body that was designed around a 24 fret neck, but you can swap scale lengths on most of them.

[DalyTek]

That's good to know, thanks Newc. Both are indeed 24 fret necks.
Like I said, I did rough measurements on both bodies and it seemed everything matched up.
Not sure if i want to do it or not though.

Have to ponder:
Do I want 2 original Jacksons (one with my favorite body and one with my favorite neck)
- OR -
Do I want 2 parts mutts (one with my favorite body and favorite neck and one to sell)
hmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm.....

PS: Would the fusion body with the KE3 neck essentially then be a parts mutt Dinky?

[MetalMedal II]

You cannot intonate a 25.5" scale 22 fret Jackson neck on a Jackson body that was designed around a 24 fret neck, but you can swap scale lengths on most of them.

Cool, I didn't know that. I've got a charvel fusion that now has more options!

[moku]

the scale length does not determine the number of frets. rather by how long the fingerboard is. the scale length is the distance between the nut (or the end of the fingerboard) and the bridge's saddle, which will determine where to place the 12th fret octave for proper intonation.
i know many of you know this but just to be sure, intonation is not tuning. you can tune the guitar to pitch open strings, but at 12th fret harmonics (or at higher frets, the strings don't play at the pitch they should) the guitar will not be in pitch. this is improper intonation. when the strings are also in pitch at the 12th and stay in correct pitch on higher frets, that's what's meant by intonation.
what i don't understand is, irrespective of how many frets a neck has, in order to compensate the scale length of a guitar, the distance btn the end of neck pocket and the floyd bridge posts/cavity will be drilled accordingly to match the proper scale length. so if you swap a neck with diff scale on a body that's meant for another scale, how is that ever going to intone? :think:
this is precisely why "you cannot intonate a 25.5" scale 22 fret Jackson neck on a Jackson body that was designed around a 24 fret neck." even if both necks are 24 frets and are exactly the same length, if the body's neck pocket distance to the bridge posts/cavity is different, it will not intonate properly.
given that the floyd saddle can be adjusted forward and backwards to accommodate proper intonation, but still the scales btn 25-1/2 and 24-3/4 is too great to adjust the saddles to get that intonation. besides, there should be compensation on the length of the strings anyway (string length of a 25-1/2 scale guitar is actually slightly longer than 25-1/2) for proper intonation. the floyd saddle will not be able to move back and forth far or close enough to have proper intonation.
would someone pls tell me where i'm wrong in this?

[DalyTek]

Yes, moku, what you're saying for the most part is correct, and was pretty much what I was thinking (hence why I posted this thread.)
However, my measurements showed otherwise. Here's what I think must be what is happening (this is only my personal opinion, so do not take it as fact!):

The scale obviously needs to be changed on the fretboard, that's a given.
Logic says that the neck pocket position or Floyd Rose position would also need to be changed to place the saddles at the proper distance to complete the scale.
What I think Jackson actually did, though, was to change the alignment in the heel of the neck itself, keeping all changes in the neck.

If that's the case, then what Newc says is correct, and you can use any 24-fret body with any 24-fret neck (regardless of scale length) as the neck alone determines the scale length.

[moku]

What I think Jackson actually did, though, was to change the alignment in the heel of the neck itself, keeping all changes in the neck.

by "alignment," you mean not push the neck heel against the neck pocket (not match the neck holes), but adjust it so that the scale length would match?

[DalyTek]

No, not at all. I mean they actually changed where those holes are drilled into the heel in the first place to match up to the body.

[DonP]

would someone pls tell me where i'm wrong in this?

Yes. In the real world, it works.

I've not compared a 24 fret short scale to a 24 fret long scale, but Jackson has them adjusted with overhang or whatever so that there is no worry with swapping necks.

[moku]

matching the holes so the new neck line up does not change the distance of the end of neck pocket to the floyd post....