Official Luthiers Forum!

[QUOTE=Pwoolson]
Now, if you weren't misunderstanding and this is indeed what you were thinking, I'd be curious as to how you would do it by hand.[/QUOTE]

Paul-
I think I understand the idea- you want to have a constant-depth fret slot to avoid weakening the center of the fingerboard with the over-deep slot?
My recollection of the Lewis jig ( I sold mine a number of years ago) is that you could put a curved guide in it to help guide the saw- it did require some attention while sawing. (The saw depth indexed from the backsaw spine).
If you cut your slots on the table saw, cut them just deep enough to act as a guide for your handsaw (after they are radiused).
Clamp a depth guide to your handsaw blade and deepen the slots by hand.
Of course this wouldn't work if you radius your fingerboards after the FB/neck is glued to the body, but obviously if you are doing your fingerboards by CNC this doesn't apply.
I had thought about this a bit- it seems that you would see more effect on the tight radius fingerboards (12" & less) and since I don't use less than about 16" radius, it wasn't worth the trouble.

My comment on CNC was mostly in jest- though I do have problems with the concept of 'handmade' and CNC working together. Heck, I have problems justifying 'hand-built' with using the router- and believe me, I do use routers (a lot!).

Cheers
John

I have a good concept of how to make a jig for curved slots on a table saw, but I don't even own a tablesaw so it would be sort of a moot point.

As for cutting the slots curved, like we CNC guys do, it's just a matter of duplicating what we do with jigs instead of numeric control. Use a router base on a Dremel, which allows you to set constant cut depth relative to the running surface (the radiused top of the FB), and then just make a jig so your router runs across the fretboard in a straight line.

There's also a way to design a jig such that you can do the above, as well as cut the slots short of the edges like we CNC guys do. Maybe I should patent it and sell it to the Luddites here

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

There's a major misunderstanding going on here about what I do with the graphite in the fingerboards and necks...

It's not 1/8" x 1/8", that would be kind of dumb.

It's 1/8" x 1/2" tall and I put two in the full length of the fingerboard. The height is reduced over the body, but in the neck it's full height. I dado 1/8" deep slots into the underside of the fingerboard and glue the graphite in

As far as the "system" goes, it's not quite accurate to dismiss the contribution of an ultra stiff fingerboard system to the overall stiffness of the neck.   I consider this fingerboard system to be the primary structural element of the whole neck, and the great thing about it is the stability that it imparts to the line of the fret tops.   There is no issue of a hump or dip at the neck joint, and the fingerboard stays incredibly predictable...and that means playability is predictable.

The Antarctic guitar has not needed any neck work since the day it first left my shop about six years ago. That guitar has been through some of the worst climactic changes I can imagine, and it still plays great. There is a double acting truss rod in the neck, and it's there to allow adjusting the relief in the fingerboard, not to compensate for any weakness in the neck.

This concept of a structural fingerboard is not the only way to build a good neck, but it sure works for me with these instruments.   As we move over more and more to CNC manufacturing here, I'll be extending this way of building necks into more of the instruments we build. It will also be perfect for the ceramic fret project where fret top stability becomes paramount as there's no possibility of doing any fret milling.   I showed a guitar with ceramic frets at the SIMSCAL meeting, and it, too, had one of the "structural fingerboards".

BTW, we just picked up a fantastic review of one of our 16 1/4" jumbo guitars in the latest (just out) issue of Guitar Player Magazine. Also look for a photo essay on how we build them in an upcoming Fretboard Journal.

These guitars are also built with graphite topped back braces and a continuous back center seam reinforcement   ...no cuts through for the back braces. The braces are notched over the seam strip.   Also these guitars have four flying buttress braces connecting the neck block to abutments glued to the sides in the waist. This allows us to use very little bracing in the upper bout as the top isn't carrying the compression load of the neck.   

See, now it makes a lot more sense, and is an extension of the practice that a number of people use of the CF in the neck, but just extended up higher into the fingerboard. You have the 3/8 in the neck and an additional 1/8 extended up into a dado in the FB.

My own necks have the CF carried through the neck extension extending into the body of the guitar so also avoiding the 12 or 14 fret hump, as here.



I'm not sure how much stiffer moving CF up into the fingerboard would make the neck system once it's all glued together, but it certainly can't hurt.

I belive that Howard Klepper and Dave White also use the CF buttress braces in their guitars for the same reason.

Thanks for the clarification 1/8 x 1/8 just made no sense.


Colin

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

I'm not just moving the graphite up. Normally I use 3/8" tall by 1/8" wide strips.   Dadoing up into the fingerboard allows me to use 1/2" tall stock...33% taller and probably close to 50% stiffer than I could otherwise use.

For a well-respected magazine writer's take on the results we achieve, check out Art Thopmpson's review of the Koa/Russian jumbo that we just got in the latest Guitar Player Magazine...the August issue. I'll just say that seeing that triggered a major grin festival around here...

While the whole bit about the neutral axis is absolutely correct, it's not all there is to designing and making necks.   I'm advocating for maximum stability in the fret tops...and that's not exactly the same as saying maximum stiffness for the neck.   Also, putting the graphite at the surface...which is what my 1978 patent is all about...severely limits neck shape options and makes for very expensive tooling.   Also some...many...maybe most...guitarists like the feel of a wood neck, and there's no arguing with what the customer likes and prefers. I have all the options I need making graphite reinforced wood necks.   Shape, width, scale length, aesthetics...it's all easy to customize.    

The other thing that I'm doing is freeing the upper bout of the top to vibrate, and I think it pays off. Most of the other "modern" neck attachment designs I see involve virtually immobilizing the top in the upper bout, and I just have to wonder what the idea is behind that. Is it because builders don't know how else to stabilize that area. or is it because they really feel that tone is enhanced by having virtually no vibration of the upper bout? I feel the upper bout top contributes a lot to harmonic sustain, and I hear a kind of woofer/tweeter relationship in how my tops vibrate compared to conventional building techniques.   

Thanks for the info Rick. I am curious though about something you said. Which types of necks are you referring to as modern neck attachments? The full bolt down fret board extension or something else?

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

Well if we're talking sheer numbers, then the "new" Taylor neck joint certainly qualifies, but from my point of view, so do the designs from Steve Klein, Collings, Bourgeois, and in fact, Colin's neck pictured above.   These all involve immobilizing the top in the upper bout. So, for that matter, does Smallman's system and Humphrey's design as well.

Yes, I know that I'm not the only one doing cantilevered fingerboards and alternative neck block support, but I'm probably the first one in our generation of luthiers to have made a real connection with the Howe Orme guitars and try to bring that 100 year old design forward.    This active upper bout thing had me convinced 45 years ago that most guitar makers were giving up on something potentially very valuable.   Try to get your hands on a Howe Orme guitar and really study it. They're quirky guitars, but they're also incredible sounding instruments, and they rank among the first production steel string guitars as they came out several years before Orville Gibson and more than twenty years before the introduction of the Martin 2-17.

I did learn that they have a structural flaw, and that is taken care of by the flying buttresses in my guitars. My whole exploration right now is in separating as much as possible the structural elements of acoustic guitar design from the tonal elements. I know that they will always be linked to a certain extent, but it is possible to tease some of the issues apart and gain greater freedom in designing for tone.   So far I've been right in how to achieve what I'm after in the timbre, volume, and sustain of my guitars, and it has been a process in which we built a bit stiff at first, not wanting to go too far and have warranty issues.   But now that I'm confident in the structure, we've been able to take the tops and the bracing down thinner and thinner and the guitars have gotten louder and louder and the break in time is less. We've kind of hit our goal now, so the game is manipulating each top to achieve the current result. If they all sound pretty much like the latest two, then I'll be a happy guy.

I'm also going to advocate here that modern steel string and nylon string guitar builders spend a lot of time with antique and vintage instruments.   There's a lot to be learned there, both good and bad. Knowing how guitars react to years of tension and compression is vital to knowing how to avoid the common failure modes in your own work.   I think too many luthiers either bypass or move away from repairs and restorations too quickly in their careers and miss out on a kind of grad school education that is important.

Rick, good stuff...thanks for the clarification. I'm looking forward to hearing more about your use of ceramic frets. That should be really interesting to see and hear!
Do you foresee any issues if you need to remove the fretboard at some point? It would seem that having the CF rods in both the fretboard and the neck itself could make removal very tough, if not impossible. Of course, I guess if it's all done via cnc, perhaps there would never be a time where that would be an issue...

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

[QUOTE=Rick Turner] Most of the other "modern" neck attachment designs I see involve virtually immobilizing the top in the upper bout, and I just have to wonder what the idea is behind that. [/QUOTE]
Hey Rick! It's good to have you back on the forum!

Now, I'm only a novice, but I've thought for a long time that attaching a chunk of hardwood onto a softwood top seems like a bad idea. Early guitar makers apparently thought so too, as they continued the lute-building practice of ending the fingerboard at the body joint, and putting the additional frets directly into the top. The obvious solution is to simply lift the fingerboard off the top. However, leaving an unsupported fingerboard flappin' in the breeze doesn't work either. It'll move around, either from its own stresses or from finger pressure. You solved the problem by continuing the graphite supports under the 'board extension. Great idea!

I got my copy of the above-mentioned Guitar Player in the mail yesterday, and they raved about Rick's guitar in virtually every respect. They thought it worked exceptionally well whether using picks or fingers, and delivered outstanding tone at all times. They also REALLY liked its adjustable neck system, which "floats" the heel as well as the fingboard. I may be wrong, but I don't think there's wood-to-wood contact anywhere at the neck joint. All that, and it looks good too. Way to go, Rick!

Just gotta express my gratitude again for how much I learn and gain from Rick's ideas, experience, knowledge, innovation, wisdom, and willingness to share all of the above. Every time Rick opens his mouth (or designs a new guitar), all my understanding and thinking about designing and building guitars is greatly deepened and expanded.

Can't thank you enough, Rick.

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Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/

Rick what thickness is your fretboard? Is there any issue with taking that much wood out of it? refrets,  releveling as it ages?

Thanks your take on necks is very intresting

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Zac

Anchorage Alaska

Finshed my 1st! See #1 here

I don't understand why people use cf bars when rods are so much stiffer?  Bars have considerable side to side flex.  

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A higher purpose for wood.
Rich Smith
Issaquah, WA

Let's see...

Rods vs. bars...some of it has to do with convenience. I use both, and it depends on where I need the stiffness and stability and in which axis the majority of the stress is applied as to what I choose to use.

Fingerboard removal...it will be a bit of a drag, but not impossible by any means. I'd mill off about half the board...down to the CF reinforcement and then glue back on a 1/2 thickness board. Or something like that! A solution will appear when it becomes necessary to do it.   I hope to be long dead by then...

Chunk of hardwood to a softwood top...that's really not what I'm objecting to.   I'm objecting to using the whole upper bout of the top as a structural support for both the neck block and the fingerboard extension. It's just throwing mass at a problem that's better solved with engineering. If you like the sound of a constricted upper bout top, then you can still do that with how I build. There are millions of guitars out there built with locked up tops, and probably several thousand of those are great guitars.   I'm just trying to open up my options and be able to choose whether or not to restrict top motion independent of the need to support the neck and fingerboard pressure.   Then, of course, there are all these other advantages that I see doing this including the playability factor with no dip or hump on the fingerboard at the neck joint and the ability to practically instantly adjust action up and down, and then to be able to adjust over-all intonation.   The only down side that I've run into is that it looks weird to some people, but I'm not willing to jump through hoops to hide this design. I suppose the heel could be let into the end of the guitar, but that would compromise some of what I like about the whole thing.   Besides which, if banjo players can love all the mechanical details they deal with, then guitar players can lighten up and learn to love convenience, too.

My fingerboards are about .250" on these...pretty normal.

Refrets with normal frets...no different than on any other guitar.   With the ceramic frets...not necessary in my lifetime, but doable in the future. They're bar frets in fret-wide slots. Heat 'em up, pull 'em out, put new ones in bedded in epoxy with a height alignment jig.

In reality, it takes a very, very long time to wear out a decent fingerboard, and the modern take on a lot of that kind of repair is to fill fingerboard divots with superglue and sawdust rather than plane down the 'board. That should take any modern guitar out a good 75 to 100 years based on the repair work I've done on vintage instruments. Out that far...well, as you've read, I just don't much care. Someone will figure out how to fix it.

If push comes to shove, it takes all of about ten minutes to replace the neck with a brand new one...and that includes tuning. It's no more difficult than changing a neck on a Strat...and maybe it's easier because it's with a pin bridge.

One of my plans is to make a baritone neck available for these. You could have one guitar body and a standard and a baritone neck...

Ricardo, it's all in the orientation. If the bar is wider than it is thick, say 1/2" X 1/8", it's extremely difficult to bend it with the wide dimension vertical. It works just like a tall-thin wood brace, and that's the way it's inlaid into the neck. Virtually no force is applied to it side-to-side. It wouldn't work as well if the forces were pushing on its ends or in the middle of its wide dimension. A cylinder-shape rod would work better in that case.

[QUOTE=Rick Turner]One of my plans is to make a baritone neck available for these. You could have one guitar body and a standard and a baritone neck...[/QUOTE]
Somebody needs to stop this man before he uses up all the good ideas!!!

I'm using the bars in a vertical orientation, and at this point we're picking nits. These necks are as stiff as they need to be and they're stable as well.   

I've done the way over the top stiffness thing with the earliest of the hollow graphite necks, and you know what? A lot of people don't like how they feel and sound. Sure they are run 'em over with a semi stiff, but is that really the goal? I no longer think so.   

Jeff Traugott and I have had a lot of discussions on this whole thing of neck stiffness and how it affects apparent string tension.   Note the word "apparent", because that's what musicians talk about, and it's different from what engineers talk about.   It's about the feel of the string working with the stiffness of both the top and with the neck.   I know, I know that for a given scale length and a given string gauge and a given pitch there is only one answer to the tension question, and I know that nothing you do behind the nut or below the saddle affects string tension.   But everything affects string feel, and that's a biggie for musicians.   So Jeff and I discuss the effect of stiff tops, necks, graphite bars, break angle, all that because even though we both build pretty consistently to certain scale lengths (fanned frets notwithstanding) sometimes a guitar will feel like the strings are at lower tension.   Why? Well, that's where the dark arts of lutherie come in to play. I only suggest that when we all discuss that among ourselves and also with civilians that we not confuse real string tension with apparent string tension. It's about like true north and magnetic north...the closer you get to one truth, the farther away the other truth appears to be.

[QUOTE=Rick Turner] Fingerboard removal...it will be a bit of a drag, but not impossible by any means...I hope to be long dead by then...
[/QUOTE]


Yeah, with the CF in there, I'm guessing someone would have to put tens of thousands of hours into wearing down the fretboard.

I'm curious about how you would radius the ceramic frets...and how you would do the setup work. If memory serves, ceramic is really hard stuff, and not easily shaped with files. You using a Plek machine for that?

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

Rick, another approach to having a large as possible unobstructed soundboard is the two hole guitar a la Grimes.  This has my attention. I have heard these guitars and am amazed at the sound coming from them.  Grimes argues that by replacing the large central sound hole results in a larger sound board producing sound.

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A higher purpose for wood.
Rich Smith
Issaquah, WA

Rick

I am learning to build ukuleles and noted on the sample video that you cf reinforce the neck do you use just one bar? and is the fingerboard floating on a extension of the neck?

Thanks

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Zac

Anchorage Alaska

Finshed my 1st! See #1 here

A couple of comments...
The Grimes thing (also done a long time ago in the classical guitar world) is interesting as is the fact that he still builds guitars with conventional soundholes. The double hole version is the Keola Beamer model, as I recall.   Moving the soundhole(s) changes the sound in somewhat a different manner than opening up the top above a more conventional sound hole.   Doing as I've done is almost like having a second discrete area of the top rather than one larger area.   

In the ukes we just use one 1/8" x 1/2" bar on the flat under the center of the 'board running from about the 8th fret to the end of the fingerboard.   It works just fine that way.