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heres those photos of the hofner. It is easier to adjust without tension, a little is good, and since it does pivot the neck it does change the tuning. It does also make it very easy to remove the neck.I think it could be used different then I do, meaning a shim could be installed under it and then it could be tightened on the shim for a better fit. Anyway here they are, any questions just ask,,




notice the far left of the neck tenon, it appears to be compressed slightly. I believe this is the pivot for the neck.



The neck tenon pivots on the raised wood in the back of the pocket and is pulled down by the hook.




the locke ness monster,, oh sorry wrong photo thats the hook. Hope these give you guys some ideas what to do or not to do.. Mike

Grant Goltz, who is a member here, has come up with his own variation of an adjustable angle neck system. Basically, it is a bolt-on, mortise and tenon using cross dowels, but the base of the tenon (closest to the heel) is angled. In his original prototype, he used a piece of spring steel on the lower bolt, but I think he has abandoned that as unnecessary. The neck heel does not butt to the guitar body rim/side, but instead the side material is cut out to allow the neck heel to be repositioned without seeing a gap.

An (invisible) fingerboard extension is glued and doweled to the neck, sort of similar to an archtop, and the top is cut out to allow that extension to rise and fall, with the fingerboard just above that. Done correctly, the initial setup has the fingerboard down nearly flush to the top, and appears just like a glued-down fingerboard. When resetting the neck angle, normally the nut needs to be dropped down, which the tenon angle handles. In an odd case where the nut needs to rise, the entire neck could rise a bit in the mortise slot, so that the bottom of the fingerboard could again be very close to the top after the neck angle is altered. In other words, it is not strictly a fixed pivot point, but more correctly a "pivot zone", to allow the engineering and the aesthetics to work well.

I looked at Harry Fleishman's method too, and it is cool, but the woodworker in me wanted to "see" the strength of a tenon, so I went with Grant's system for my first guitar.

Grant's method works with great stealth on a non-cutaway or square-corner cutaway guitar - you wouldn't know it was there (until you wanted to reset the neck angle in 30 seconds!)

When working with a compound cutaway, the neck heel must slide past the cutaway's end binding, so for this most difficult combination of compound cutaway and adjustable neck, the neck heel must be inset the thickness of a piece of binding. Kind of like this:


Side Cut, to Inlet Neck Heel (There is a bit more work to be done here - I will remove a small amount of the neck block down near the heel, to allow the heel to drop even a bit further back into the body, if ever necessary.)


Adjustable Neck in Place

Grant is great about sharing, and can supply further details if anyone is interested.

Dennis

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Dennis Leahy
Duluth, MN, USA
7th Sense Multimedia

I believe this is a basic illustration of what you're after. I've had this knocking around inside my head for months now, but it is something I've got to try at least once.

Dave and John, So, you're saying that even with the scale unchanged ( the nut being the fulcrum point in this design ), that the change in string height will still change the intonation because difference will be in the contact point at the frets?

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DES - Shepherd, MI

Darin,





Your image is exactly what I was attempting to describe with words.The attached image is a neck housing block I was working on. I had a independent block sliding within the housing which bolted onto the neck but I figured that an intermediate compenent increased the chances of neck distortion/deflection and may have adversely affected the sound. It is not elegant or well machined but it enabled me to test the theory.Incorporating truss rod and action height adjustment caused me to pause and reflect at its complexity. I should have my next version assembled soon. Of course being the devil's advocate I have asked myself the question "Will the intonation variation produced by a greater or lesser action height make the adjustable neck pointless?"

Tim
Perth, Australia    Black Swan38787.1520949074

Tim,

I don't think any variation on an adjustable neck is pointless. Just look at how many professional luthiers have resigned themselves to the "reality" that "eventually, every acoustic guitar will need a neck reset." With an adjustable neck, the guitar does not have to eventually face a dismemberment and fixed neck reset procedure.

Intonation is a related but different issue. If a player wants a minor adjustment in action, I think that the concept behind your design or Jeff Babicz's design, or any design that allows the neck heel to go up and down will allow a small action adjustment without changing the intonation perceptibly. Note that word "perceptibly", because a strobe tuner will detect any intonation change, but I'll bet most players could not.

I think of the goals of adjustable neck engineering as taking two paths: in one (ideal) scenario, the neck is freely adjustable between players and maybe even between songs that would get a benefit from an action change. In that first scenario, the pivot point or lack of a pivot point is critical to getting the most action adjustment with the least change in scale length. In another scenario, the adjustable neck is both a way to make the initial neck angle "perfect" more easily, as well as "insurance" against having to eventually do a brute-force fixed neck angle reset involving neck removal. In that second scenario, perhaps the neck angle adjustability is only used twice in the guitar's life - but still well worth it!

In terms of the "insurance" concept, if you use a wide saddle blank, and place it (and the bridge) initially in a position that will work well for the guitar's initial setup, keeping the saddle as far forward (toward the nut) as possible, that will "eventually" allow either the old saddle to be filed back or a new saddle blank to be dropped into the slot and the new saddle filed to get the guitar's intonation correct for the new string length. The fact that it can be accomplished without neck removal is again a very worthy concept to me.

Just my $.02.

Dennis

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Dennis Leahy
Duluth, MN, USA
7th Sense Multimedia

Dennis,

Thanks for your $0.02. Your comments are worth much more than that. It is very helpful to a broader perspective on these issues. When I have produced my third model I will post it in the forum.
Thanks again

Dave, I do struggle also with making the cutaway side of the body match up well with the adjustable neck. I have had to make the body a little bit bigger than the neck inside the cutaway to allow for a pocket, and I can't figure out a better way to go there.
As far as intonation goes, I think some of you folks are analyzing it a bit too far. If you set the bridge right at the start of the guitars' life, the adjustable neck will just help you make sure that the action stays where you placed it at setup. Even during an action adjustment by moving the neck angle, intonation doesn't change perceptibly, and the set screws at the pivot point (Doolin's method) give room to move also if you have to- but you probably won't. Mark Swanson38787.3971180556

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Mark Swanson
Swanson Guitars
http://www.MarkSwansonMusic.com

WOW! you guys are amazing, i thought the dovetail joint and then the bolt on neck was the end of it, no wonder i'm posting like a mad pup, i'm overwhelmed by the innovation and creativity and cleverness that is being displayed every day before my own 4 eyes!

Harvard or Yale here???!!!! now please don't take sides ok! just glad to be here with great minded folks!

Serge

Tim (or is Timothy preferred), Another issue I struggle with in our concept is excessive weight at the neck block. Does your next version address this?

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DES - Shepherd, MI

Good question
Weight is an interesting point. I am anticpating that the next neck assembly would weigh in at 150 grams. A mechanism for securing the slides might add another 20 or 30 grams. For strength I think I will have to form my own laminations.

Tim

Well, my adjustable neck is pretty well documented on the "no S" forum, plus 3 complete builds using it (and a whole host of my other "tricks" ), but I will post a bit of it here when I get caught up with a few things. That might take a week or so.

In the meantime, just a few notes. I use no hardware other than the two neck bolts, and a handmade spring that is 1" wide by 1 1/8" long and .035" thick plus a pretty standard sized neck block for a typical 1" wide tenon. So additional weight is not an issue. I suspect my joint may be somewhat similar to Doolin's, but I have not really seen any details of his, so I don't know. I do not have any extra set screws, etc. mentioned in above posts.

As for intonation changes with adjustment, I think it is esentially not an issue with what I do. The maximun adjustment possible on my system (which will more than put the strings tight on the fingerboard) can only theroetically change the total scale length by .0125". That is 1/10 the width of a 1/8" bridge saddle, so should be easily adjusted for if needed. However in a more realistic scenario, since a .01" adjustment in string height at the 12th fret only changes it by about .0016", nothing really needs intonation changing.

The key is to start off with everything built for a comfortable medium action and no need to worry about intonation changes under "normal" conditions. Now if you at some future point, use the adjustable neck to avoid the normal neck reset, you might need some additional adjustments to make up the difference. But what about the shortening of the string scale by natural neck/top colapse and then a neck reset. That will typically really screw up the intonation

On my compound cutaway builds using this system, there is an offset between the edge of the neck heel and the cutaway side equal to the thickness of the side. If you bind the end of the cutaway side and round the edge of the binding a bit, it is hardly noticeable.

Tim, I got your "other message" and will get back to you.

Grant

Serge, it is amazing, I still struggle with setting a dovetail joint and getting the neck straight, this is well above my head, but this is how we learn the finer things in building. Mind overload on this one!

Mike
White Oak, Texas

Mike, if you succeeded in having a dovetail joint, you're my hero, that is whut i tried on my first and let me tell ya that i ain't gonna mess with that kind of puppy no more! My next joint will be bolt on and maybe, i'll try to improve with Sylvan style pocket rest for the FB, that will be hard enuff for me to accomplish! and if i do succeed, i'll probably have to let my Bear brains rest for some time afterwards!

Hi Tim,

Thanks for sending the photos. I think your idea is ingenious. On the other hand, I would tend to agree with others who've suggested that intonation concerns are not really warranted, esp if you think in terms of the neck adjustment being primarily used to bring the geometry of the neck and top back to where it was when the guitar was built, before the top began to torque and "belly". Slight adjustments that a player may make to get their ideal action shouldn't affect intonation perceptibly. Whatever very slight change in intonation there might be, if the player is perceptive enough to actually hear it, would likely be fixable with a change of strings, since different brands of strings intonate slightly differently. Or, an adjustment at the saddle, maybe a new saddle if necessary.

I tend to look at the adjustable neck as an alternative to an eventual neck reset, as well as a way to get the action just right after the new guitar has settled in, rather than adjusting the saddle height, which may adversely affect tone. I don't think of the neck adjustment as something that's going to be used frequently.

Maybe there are some players out there who would like to be able to adjust action on the fly, but I doubt there are many. The idea of a neck joint designed, and _marketed_, to be adjusted between songs, so to speak, strikes me as a bit of a gimmick. That's my humble opinion at this point in time, and I'd be delighted to hear from anyone who disagrees with me on that.

As I work on my adjustable neck joint, one of my highest design priorities is simplicity. And I'm thinking more in terms of simplicity of construction rather than simplicity of adjustment. I don't want to make it a bear to adjust, of course, and it needn't be - but virtually any sort of adjustable neck is infinitely simpler than a neck reset, and that's the main goal, as I see it.

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Todd Rose
Ithaca, NY

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

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

Todd, I agree with you 100%. That is why I designed my adjustable neck system the way I did. Other than having to inlet the neck heel through the sides, which takes about 15 minutes, There is really no more work than a regular tenoned bolt-on neck. Everything else is just a matter of doing the steps in the proper order. When I first started this, I thought I would need to apply an upcharge for the adjustable neck. After the first couple, I realized that there was no problem just including it in my base price.

The system should not be thought of as being an excuse for sloppy building. The key is making sure that neck alignment and angle is dead on at the beginning, but that is a realitively simple matter with this system.

As for intonation problems, I agree that it is a non argument. This is not something that will typically be tweaked on a regular basis. In the two years since I built the first prototype guitar, I think I have made minor adjustments only 3 times, once about 6 weeks after the instrument was finished and had settled in, once about 6 months later to try a lower string action, and once about two months ago for a player who is trying it out and has a more vigorous playing style and wanted the action just a tad higher.

The system is, however, infinitely adjustable. The starting point allows about one complete turn of the lower bolt, which is the adjusting bolt. This can drop the nut almost 3/8". If, at some point in the future, the instrument has warped so badly that this not enough, the 2 bolts are the only thing that holds the neck on. The fingerboard is not glued to the top as on a typical bolt-on, but is supported on a neck extension which floats in a cavity below the top. So, if need be, the whole thing can be easily removed and the tenon end and whatever else needs be, can be shaved down a bit for even more adjustment room. Simple, effective, and designed at the minimalist level. That's how I like things .

Grant

Todd

Thanks for the feed back. I will get back to working on model #3 factoring in simplicity and and ease of construction.

thanks
Tim

Grant, now I've really gotta see some more photos and details on your system.

Sorry, but I'm not hip to the code word "no S" forum...

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Todd Rose
Ithaca, NY

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

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

[QUOTE=Todd Rose] Grant, now I've really gotta see some more photos and details on your system.

Sorry, but I'm not hip to the code word "no S" forum... [/QUOTE]

luthierforum.com

Name almost the same as this one except no "s".

Search on "Grant Goltz adjustable neck". It may only search the last 30 days, but reset it to "from the beginning". There will be a list of topics, "full scale mockup", "building the box", etc., etc.. The names should be self explanitory.

I will try to get some photos over here after I finish the current guitar and get caught up on my wood orders.

GrantGrant Goltz38788.9273842593

Can't wait to see that Grant, Thanks!

Thanks, Grant, I wasn't aware of that forum. I checked it out, though, and there's a fee to join. It's not much money, but I think I'll skip it, since I don't really have time to hang out at another forum, and this one is so bloody great.

So, I eagerly await your photo posting here on the fabulous OLF.   

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Todd Rose
Ithaca, NY

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

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

Todd,

There is no fee at that forum. Check again. They use some message board software that allows them to charge a fee, so you may see a generic reference to fees if you look hard enough, but it is a free forum.

And, though this place feels like home, do check out Grant's adjustable threads over there. It's well documented, and well worth the "side trip."

-Dennis

Grant Goltz Experimental Adjustable Neck Build

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Dennis Leahy
Duluth, MN, USA
7th Sense Multimedia

I tried registering for that forum. I thought I'd completed registration, and was able to log in, but then couldn't get past this "You do not have permission to view this board
" thing. So, I emailed the forum administrator, and was told that they did, indeed, start charging people to join.

When I click on your link, I get the same thing: "You do not have permission to view this board," even though it shows me as being logged in.


Maybe I'll go ahead and fork over the bucks just to see Grant's neck joint photos, but, frankly, I'm feeling annoyed by the situation and doubt I'd ever use that forum again, so I don't know.

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Todd Rose
Ithaca, NY

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

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

Hi Todd,

I happen to be on line right now at both forums, and see you logged in at the other one.

If there is now a fee, that's news to me, and nothing about it is posted, and I have seen no discussion of it. Very strange...

Dennis
{edit - I'll ask one of the moderators}DennisLeahy38791.8965046296

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Dennis Leahy
Duluth, MN, USA
7th Sense Multimedia

Todd, when you see the "You do not have permission to view this board" message, go to the bottom of the page and you can register. I just did and there are no charges for joining the site.

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Dave Rector
Rector Guitars

I just tried to register again with a different user name, different password, and different email address, and the same thing happened to me. It lets me register, sends me the confirmation email, logs me in, and then I can't get past that same "you don't have permission" thing.

Forget it.   

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Todd Rose
Ithaca, NY

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

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