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Peter, I think you are right. A hump and fallaway can look the same against a straight edge spanning all the frets.
It's a frame of reference or semantic confusion that seems like it's been around for as long as I can remember.

For what it's worth, this is how I think of it.

If you take Hesh's two fret planes, plane #1 (1st-12th) should be flat or have some relief but never be back bowed. Plane #2 (12th-last) must be slightly angled down in relation to plane #1(fallaway) but also be flat as well(no hump). Otherwise when fretting up the neck, the second plane behaves like a back bowed neck, with the strings tending to hang up on the "hill" forward of the fretted note.

So, Fallaway could be described as a hump when looking at all the frets, but a, "true hump"(?) is a hill within fret plane #2.

Clear as mud huh?

Good grief. I gotta take a nap now,

Bingo! Thanks David.

Got it! Thanks David and Hesh

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"I am always doing that which I cannot do, in order that I may learn how to do it."
Pablo Picasso

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You bet Peter!

Hey I have been wanting to have a drawing of what we are describing here for some years now and since I am clueless with CAD software and your drawing is very close to what I need and want any chance that I could ask you to make two mods to it and repost and then be free to post it again in the future? I'll as always be happy to always provide attribution to you when ever I post the drawing too because that's what I do...

If you are game here are the two mods:

1) Lower string height over the first fret and at the nut so that the strings just clear the crown of the first fret.

2) Using the nut and the 12th as fixed points pull the fret board down in the region of the 6th, 7th, and 8th to add relief but the relief should never create action higher than what we see at the 12th.

If after the 12th there is a gentle slope to the last but in a flat plane from the 12th to the last that will be what I have been trying to describe and very useful in the future to others I am sure.

If it's a lot of work no worries I would not want to make lots of work for anyone. But if it's simple and you feel like doing it it would be very much appreciated.

Many thanks!

Glad you like the drawings! I'll give it a go when I get home. Btw, if you are ever interested in getting into CAD, google sketchup is the way - you can learn it in about half an hour!

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_________________
"I am always doing that which I cannot do, in order that I may learn how to do it."
Pablo Picasso

https://www.facebook.com/FenskeGuitars

Is there supposed to be fallaway on a classical?

Not sure if its called fall away but the classical's I've constructed actually have a taper machined on the finger-board thicker at the nut than at the extension end. This is not my idea, picked the strategy in several different publications. And there is also the methodology of tipping the FB plane up toward the sound board. Not something I'd do, especially with Spanish heel construction -- but it certainly has been done by many.

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Ken Cierp

http://www.kennethmichaelguitars.com/

This may be going out on a limb Wendy, but I would say it's less important as action heights get higher.
(setting aside the whole bending thing for a moment), because the action height on a classical is higher, the angle that the strings climb up towards the saddle is steeper when fretting high on the neck. The strings on an electric w/ low action are dang near parallel to the fret plane. Fretting an electric does not cause much upward angle to the saddle so more fallaway is required.

How much less important for a classical? hmm..... makes me want to storm the gates of the Plek data castle and steal some hard drives. Because Lord knows Ill never be able to afford the toll on that road.

No, not necessary since the action setting are much higher the extension frets are never an issue. Good question!

Now that you mention it there is not "supposed" to be fall-away on any instrument but we induce it when it makes sense because it enhances the ability for the instrument to be set-up well when low action is a preference.

Since we are builders we can do what we want and fall-away is just one of many high-performance upgrades that can differentiate a small builder instrument from a f*ctory instrument. It is at times the only way to get a client the action that they require as well...

Thanks, good to know.

One drop off consideration for me is how much the guitar settles in under string tension. I use a Bourgeois type double tenon joint and it moves more than a glued extension so if there is no, or just a little drop off unstrung the settling in will eleminate it or even give a rising extension.

The weights help me there. I level the fretboard and dial in some drop off after 12, then fret to about 9 or 10, snug up the truss rod and then support the headstock and add 6lbs to each side of the upper bout. If there is still a little drop off I am happy. If not I can still add more.

It is not foolproof as you have to try to guess how much it will settle in the first year or so. Drop off could pe perfect out of the gate and be gone in a year. I usually shoot for at least .010-.015 initially and hope it's enough.

I have had to tweak the neck set on some of my guitars that I have seen back at a year or two because of loss of drop off. The owners didn't know anything was wrong but really noticed the difference after I was able to dial in perfect action.

Have others that use the Bourgeois style joint noticed this? Have you noticed drop off issues on Bourgeous guitars you have worked on Hesh?

Obviously a fully supported extension or going back to a glued one would help but I think/hope some mods I have made may do the trick. I'll know in a year.

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It's not what you don't know that hurts you, it's what you do know that's wrong.

Hi Terry: That .010 - .015" number is a good number and what I shot for when I was building. By the way who I initially learned about fall-away from and where the .010 - .015" number came into my world from was Mario P.

Can't say that we see very many Bourgeous guitars although we had one in here last summer that a prospective buyer wanted us to check out before he got out his plastic and it was a wonderfully made and superb sounding instrument. Can't remember for sure but I think that this one was my first exposure to a torrified top as well and it was one of the best sounding guitars that I have heard in the last year. I didn't notice the fall-away or recall even checking it so no help here with that. Sorry. But this guitar did sway me in respect to torrification even though it was only one sample I'm now keen to try more and see if there is something to this shake-n-bake guitar top thing. It sure sounded promising though and I recall remarking that this was a guitar that I would love to have. That does not happen very often and some years can go by before something stands clearly out as a superb instrument.

Fall-away may never be something that even comes into play for many players but what you never, never want to see is a kick-up at the extension and sadly that's a pretty common sight that we see likely every single day. Fall-away won't harm in any way any player but the ones who need it and don't have it will be SOL and it will be noticeable.

The store where I have been selling for eight years has some great long time staff and repair folks that have been there 30 years.
The first thing they look at on a guitar is the fretboard extension. If there is a rise it is the kiss of death.

Interestingly they actually worked with a couple of major boutique brands in years past to resolve that issue.

_________________
It's not what you don't know that hurts you, it's what you do know that's wrong.

Hi Hesh, I finally got around to doing those drawings - I've moved house and the internet's only just come back online! I've done one more or less to scale, but it is very hard to spot the subtleties of the fret plane in this resolution so I did a greatly exaggerated version as well. Hope they are of some use to you.

_________________
"I am always doing that which I cannot do, in order that I may learn how to do it."
Pablo Picasso

https://www.facebook.com/FenskeGuitars

Thanks a million Peter!!!

This is exactly what I've been wanting for some years now and it's perfect for what I want it for. The exaggerated view is also a very, very good idea and helps drive the point home that I want to make with these.

Are you OK with me copying them to my computer and using them in the future? I can Photoshop attribution to you on the drawings too and that would be helpful to me if it's OK with you? I can do it any way that you wish, First name, last initial or your first and last name, you tell me what you want and I'll make it happen on this end.

Thanks again and if there is ever anything that we can do for you please let us know. This was a very cool thing that you did and it's much appreciated!!!

Happy to help! Of course you can copy them whenever you want. I'm really not bothered about them being attributed to me, but you can put my name on there if you want to.

_________________
"I am always doing that which I cannot do, in order that I may learn how to do it."
Pablo Picasso

https://www.facebook.com/FenskeGuitars

Yep... Every minute spent on achieving near perfect prep equates to maybe an hour of "Fixing" if you don't do it...

Last 2 I built - I kept working on levelling the fretboard glued onto the neck until I could "Candle" it with a Starrett precision straight edge all the way across before the first fret went in... Doing this - I think I only had to "Level" one or two frets afterwards.... This was a huge benefit for me because it made the fretwork go about 10x faster... AND it left frets more or less "Full" height to start with - not grinding down 0.005"+ across the board before it's even played..

I also found that a "Real" fretwire bender that put the correct radius on the wire before fretting also helped quite a bit - as it avoided "Lumps and bumps" on the frets that subsequently had to be removed.

For levelling... It depends on how bad it is... Diamond blocks are wonderful... If you have to take off more than a little material on one fret - a good quality fine cut flat file. I use triangle files for re-crowning and then good sandpaper to smooth the facets and polish....

Thanks

Now that I have a mill, I can probably find a 12" long aluminum beam and flatten it with the mill.

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On the diagram, I think the point of highest action is actually at the end of the fretboard, not the 14th fret.

In the above diagram, I aim for the bottom picture. Is there something wrong with that? I don't like the look of the top one. I've had builds do that. I invested a lot of time effort and money achieving the lower image. I'm talking about the fretboard, not the strings.

Oops yeah you're right!


Both pictures are exactly the same, but the first one has the angles exaggerated a lot. I think the point Hesh and others were trying to make is that the fallaway is a sharp change in the fret plane, not a bump. But still only a tiny amount, not like on the first picture.

_________________
"I am always doing that which I cannot do, in order that I may learn how to do it."
Pablo Picasso

https://www.facebook.com/FenskeGuitars

Question. The first pic looks like an improper neck angle. Would this not be the cause of the hump?

Question number two. How does fall-away prevent the hump? Or are they not related? I thought the purpose of fall-away was to give the string more room to oscillate.


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The way I read the pictures, you are correct, James, in that the first picture shows the hump being caused by improper neck angle. It looks like the rim/top angle is at 90deg. and the neck/heel angle is at the 90+deg required to get the correct string path.
I believe that picture two shows the correct compementary angle that gives the correct string path, and also allows the fretboard to remain flat from nut to sound hole. The fall-away is then shaped into the higher frets. So no, fall-away does not prevent the hump. Correct neck/body geometry prevents the hump, and in the fall-away, as you said, allows the strings room to oscillate.
Hopefully if I have it wrong, someone can correct me.

Alex

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While the drawings are certainly appreciated -- it seems the visual is causing some confusion. The variance in plane in reality is minute/tiny hardly noticeable (maybe not even noticeable without a straight edge). I believe the fall off/fall away concept -- is a newer construction tweak element, I don't do it, but I am certain there is no similarity to the dreaded 14th fret hump that is the result of an improperly made neck joint.

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Ken Cierp

http://www.kennethmichaelguitars.com/

Correctomundo! Typically at the 12th is were we get a read when chasing say the Martin set-up spec but with fall-away the action increases to the last.

Mario used to like .010 - .015" of fall-away at the last and I do too and this increases the action that .010 - .015" plus the slope of the board so you are correct.