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| Author: | bob J [ Fri Jan 05, 2007 3:04 am ] |
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I have done some thinking about the viability and advantages of not fastening fretboard. It seems that more vibration would pass to soundboard with this type of fretboard-especially for guitars that have large upper bouts-prime example,000. Ther soundboard could be thinned somewhat from waist up and the bracing much lighter. Would this create resonance problems between upper and lower bout? |
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| Author: | CarltonM [ Fri Jan 05, 2007 2:53 pm ] |
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Been thinkin' about this, too. It seems to me that a big ol' slab of hardwood doesn't belong on a lightly braced, softwood top. However, there would be some engineering problems to work out to get the board off the top. If the fingerboard is left unsupported it will likely bend under the pressure of fretting a note, and give you wimpy tone to boot (unsupported violin family instruments' boards are sturdy because of their radical arch). If you want to support the board, like an archtop guitar's extension, you'll have to redesign the neck in some fashion, so you can get a normal shallow angle to the bridge, while at the same time keeping the board's support off of the top, too. I'm by no means an expert here, but I think that there's some additional tone to be found by lifting the fingerboard extension. I certainly don't expect any resonance anomalies. |
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| Author: | bob J [ Sat Jan 06, 2007 1:03 am ] |
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Carlton, The picture of one done in this matter showed add'l bracing that braced top to Kerfing?, I believe. Strength but no add'l weight to top or back. Does anyone have picl of this technique (was it John Mayes?) |
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| Author: | letseatpaste [ Sat Jan 06, 2007 1:53 am ] |
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Harry Fleishman floats his fingerboard with his adjustable neck design. He did a presentation with Mike Doolin about adjustable necks at a GAL conference, it was published in one of the GAL quarterlies. He uses two graphite rods under the fingerboard that extend almost to the end of the fret board, and that's all there is to support the fretboard extension. I think he used to make it so the fretboard still sat flush against the top until he had a guitar come back that had some buzz/rattle because humidity changes caused stuff to move around a bit and it wasn't fitting so tight. I was particularly interested in this because this is how he taught it to us in class back in early 2004. Now he says he actually rounds the bottom of the fretboard extension a bit so that it's clear that it's purposely separate. |
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| Author: | Todd Rose [ Sat Jan 06, 2007 8:35 am ] |
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There are a number of builders doing this - Rick Turner to name just one example - and, like almost anything we might dream up, the concept is not new. So, there are good sources of design ideas out there. I'm building two instruments right now with adjustable necks and elevated fretboards with "floating" tongues. My fretboard tongue will be supported by an extension of the neck, not just carbon rods or something. I haven't actually decided yet if the carbon rods in the neck will extend into the area under the fretboard tongue. Probably will, though the truss rod will not. The fretboard is substantially elevated over the top in the upper bout area, as the top angles downward from the tail block to the neck block, giving me a "negative" neck angle. If these were normal shaped guitars (they're not), I would tie the neck block in to the waist with rigid internal structural members of some sort. On a normal guitar, the fretboard tongue, bearing on the heavy structural braces in the upper bout, plays a key role in keeping that area of the guitar from collapsing under string tension. If you take that away, you've got to replace it with an alternative structure. The way my life is these days, my progress on these instruments is very slow, but I will post some pics at some point. |
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| Author: | Dave White [ Sat Jan 06, 2007 9:12 am ] |
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Bob, Do you mean like this? |
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| Author: | Colin S [ Sat Jan 06, 2007 9:35 am ] |
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Todd I float my fB as well using an extension of the neck, the extension is a continuation of the neck wood not an addition. I do run the carbon rods through it as well, they go the full length from the head. This gives a very stiff stable neck right through. Colin  |
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| Author: | bob J [ Mon Jan 08, 2007 3:10 am ] |
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Thank you! I tend to believe a large upper-bout, 000, would benefit the most. It seems as if thee is more than enough area to contribute to the overall sound-and perhaps other shapes. |
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| Author: | Todd Rose [ Mon Jan 08, 2007 3:23 pm ] |
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Looks good, Colin. My neck extension supporting the fretboard tongue will also be a continuation of the neck wood, not an addition. In my case, with the fretboard elevated, the neck extension will be the full width of the fretboard and fully visible from the side view once the neck is bolted on. The top will not be cut out to receive the neck extension, as I assume it is on yours. |
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| Author: | bob J [ Wed Jan 10, 2007 2:40 am ] |
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Thanks, Pics and explations first rate. I did see a 'floating fretboard tongue' but the neck dod not have the wonderful adjustments you can make. Do you think a 'floating only tongue is accomplished by adding robust graphite to the top of neck? |
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| Author: | slackkeymike [ Wed Jan 10, 2007 3:23 am ] |
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Anybody got a sideview pic of a fully assembled floating neck (on the body)? Mike |
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| Author: | Dave White [ Wed Jan 10, 2007 3:52 am ] |
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[QUOTE=slackkeymike] Anybody got a sideview pic of a fully assembled floating neck (on the body)? Mike[/QUOTE] Yes, 
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| Author: | slackkeymike [ Wed Jan 10, 2007 11:58 am ] |
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Thats your Samhain model...went to your site. Very nice! Being an engineer, I am curious how that "canilever" stays off the body. But then again, playing that high up should not result in a lot of force (towards the body). Is there a noticable difference in sound? (whats that hole in the side?) Mike |
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| Author: | Colin S [ Wed Jan 10, 2007 8:46 pm ] |
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[QUOTE=slackkeymike] Thats your Samhain model...went to your site. Very nice! Mike[/QUOTE] It is nice isn't it, and morally it should be mine! One of the four best guitars ever posted on this forum. Colin |
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| Author: | Dave White [ Wed Jan 10, 2007 9:53 pm ] |
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[QUOTE=slackkeymike] Thats your Samhain model...went to your site. Very nice! Being an engineer, I am curious how that "canilever" stays off the body. But then again, playing that high up should not result in a lot of force (towards the body). Is there a noticable difference in sound? (whats that hole in the side?) Mike[/QUOTE] Mike, Yes that's Samhain. It's not technically a cantilever I don't think - just floating. I got the idea from Colin. The fingerboard extension is an integral part of the neck for almost all of it's length. I also etend the CF rods up there like Colin does. I do think this extra support helps with the notes sustain played up there. Also the dreaded "hump" is not an issue and you can merrily fret with the neck off the body. The fingerboard extension stays off the body due to it's rigidity and the geometry of the top's upper bout. The gap is tiny as you can see in the picture. I use this arrangement both with and without my adjustable neck system. I plan to use a butt joint adjustable neck system rather than the M&T one shown here to lighten up even more the upper bout bracing and neck block. I really do believe that the upper bout plays an important - albeit subtle - part in the tops ability to produce the best sound. I photo documented madjustable neck joint here on my website. The hole is a soundport. |
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| Author: | Serge Poirier [ Wed Jan 10, 2007 11:26 pm ] |
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Dave, I soo love that guitar too! Never get tired of seeing her! 
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| Author: | bob J [ Thu Jan 11, 2007 7:56 am ] |
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Does anyone have pics of how neck tongue assembly is constructed and pictures of how the neck assembly is re-enfored?-does add'l bracing extend into the box? |
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| Author: | Colin S [ Thu Jan 11, 2007 9:38 am ] |
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Bob, I'm not sure what you mean exactly, but this is how I build my necks. The components are cut to size, the first thing I make on any guitar is the neck block, this is the heart of the guitar and the bit that everything else connects to. 
After the truss rod and CF slots are cut on the table router, the neck extension is defined by sawing at the body join point and removing wood with the Wagner. 
Then the stacked heel is glued up and attched to the neck (the stacked heel and cut on the neck are cut at 1.5 deg angle) The neck is then roughly bandsawn to profile and the CF rods epoxied in place. 
I then get to work with the Japanese saw file and shape the neck. I never use templates for this I like to remove wood until it feels right. The neck extension is slimmed down. Final shaping etc takes place when the neck has been fitted to the box. 
As you can see I don't use a mortice, just butt joint, works for me. When the neck is going to be fitted to the body I rout a pocket for the neck extension in the top and the neck block. Colin |
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| Author: | John K [ Thu Jan 11, 2007 11:37 am ] |
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That is an elegant system Colin. Do you put inserts in the heel, and screw the bolts into the inserts, or do you put lag screws in the heel and run that into the guitar's interior the way Collings does their neck? It also looks like you capped off the end of the fretboard extension block with a little extra wood against the graphite rod. Very tidy. I do something similar to what you have here. But I have been bolting down the FBE block to the internal block so that the FBE is not free floating. The next step is to eliminate that block entirely, let the FBE block float in a pocket in the top and allowing the upper bout to vibrate freely....maybe |
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| Author: | slackkeymike [ Thu Jan 11, 2007 1:15 pm ] |
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That sound port is SO cool...like having a personal monitor, huh? Can you really hear the difference? Mike |
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| Author: | Colin S [ Thu Jan 11, 2007 7:50 pm ] |
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Thanks John, yes I just use the inserts in the heel, and bolts as normal. I do like to fill the slots in the extension against the carbon rods, it does make it tidy. I know nobody will ever see them once it's all put together, but I'll know they're there. This neck is in cherry by the way, and is my last scarf jointed neck (probably), over to V-joints now. How is the new place working out John? Colin |
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| Author: | John K [ Thu Jan 11, 2007 10:29 pm ] |
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New place is working fine Colin. I have been snowed in for the past two days so lots of construction is going on. Still a little disorganized, but I am not sure that any kind of move will completely cure that. How much space is there between the fingerboard extension and the top on your guitars? John |
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| Author: | Colin S [ Thu Jan 11, 2007 11:40 pm ] |
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I think something between a smidgeon and a soupson John, The gap is measurable but not really visible if you know what I mean? Never had a buzz though, and like Dave I really think it helps sustain. Glad to hear that the place is coming together, your website is the first I go to for inspiration, just looking at all those gorgeous guitars, drool.. Colin |
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| Author: | SniderMike [ Fri Jan 12, 2007 1:20 pm ] |
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Colin, that is a beautiful and elegant design. This is probably a dumb question, but I'm curious what the top extension on the neck block is for, if the fingerboard is not fixed to it? Is it just to support the top? |
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| Author: | Todd Rose [ Fri Jan 12, 2007 3:30 pm ] |
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[QUOTE=bob J] Does anyone have pics of how neck tongue assembly is constructed and pictures of how the neck assembly is re-enfored?-does add'l bracing extend into the box?[/QUOTE] Bob, if this is what you're asking about, here's two photos (I sure hope I'm not doing the wrong thing by copying these here, but both of these guys have freely and publicly shared these photos, so I'm pretty sure it's okay; my sincere apologies if I'm mistaken). The first is how Mike Doolin supports his neck block, and the second is a method Rick Turner has used. From a structural standpoint, I would not decouple the fretboard tongue from the top and the underlying bracing without adding something structurally to the neck block/upper bout, as these guys have done, to keep this vital structural area from collapsing over time. 
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