The Dreaded M&T Neck Joint

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Dobroguy
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The Dreaded M&T Neck Joint

Post by Dobroguy »

Hi Folks; I've been a lurker for awhile and I am now working on my first Blues Creek kit guitar (HD-28). I've built a few acoustic and electric guitars in the past, all with decent results. However, this is my first experience with a M&T neck joint. John's videos make the task look easy but I always seem to run into a problem or two along the way. Anyway, I'd appreciate some advice as to how to proceed from here:

The first picture shows the first time fitting of the neck as it relates to proper neck angle. The edge of the mortise cut-out has been chamfered and the neck has been "clamped" into place. It currently sits 1/4" proud of the guitar top. I have placed a 1/4" thick piece of balsa wood up against the neck joint and also at the bridge position for reference. The bridge balsa piece has a 3/32" drill bit sitting on top of it. I believe this is approximately the correct angle for decent string action?


The second picture shows how much I have to adjust the neck heel to arrive at the proper neck angle. The spacer between the heel and body is approximately 1/8" thick at the bottom of the heel. Now I have to decide how to adjust the heel. Your advice would be appreciated. I'm thinking of just adding a tapered vertical shim on each side of the heel rather than sanding the necessary taper into the heel itself. This shim could be made either from "inconspicuous" mahogany or contrasting Sitka spruce. Personally I think Sitka would add a nice visual effect at the joint. Perhaps this option wouldn't please the traditionalists among us but nothing ventured, nothing gained?
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phavriluk
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Re: The Dreaded M&T Neck Joint

Post by phavriluk »

If this was my project, I'd try to get my advice from one source to control mixing techniques. And this being a Blues Creek project, I'd be talking with Mr. Hall.
peter havriluk
ruby@magpage.com
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Re: The Dreaded M&T Neck Joint

Post by ruby@magpage.com »

Good advice on talking to John. Looks like the tenon is not seating down far enough so the neck is sticking up too far AND the tenon is not going into the mortice far enough. Both situations should be easy to fix.

If you think the M&T joint is dreaded, just try a dovetail for the first time. Like most operations on a guitar, the first time is headscratcher/worry/mystery, but the second time is easy. I take pictures so I can refer back when I do an operation again.

Good luck

Ed
Ed M
johnnparchem
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Re: The Dreaded M&T Neck Joint

Post by johnnparchem »

Is your neck joint a bolt on mortise and tenon joint? It seems like you are sort of following a guide for fitting a dove tail joint. If it a bolt on I would go ahead and start adjusting the neck angle with the neck flush in its finial position and the drill bit sitting on the top at the saddle location.

If the neck angle is still that much over angled instead of a shim start taking off from the fret board side of the heel cheeks.
Dobroguy
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Joined: Tue Jan 30, 2018 8:11 pm
Location: Anola, MB

Re: The Dreaded M&T Neck Joint

Post by Dobroguy »

Thanks for all the replies everyone. Your insight is much appreciated. John my guitar has a dove tail joint. This is my first dove tail experience. After sleeping on my dilemma last night I watched the BCG neck setting addendum video and the light came on. I didn't chamfer the neck block edge enough at first, which prevented the heel from moving into proper position. After chamfering it a little more my neck settled right down properly and it looks like everything is perfect at this point. I'm now confident enough to lower the neck into position.
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tippie53
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Re: The Dreaded M&T Neck Joint

Post by tippie53 »

do not glue the fretboard on as that make working the joint very difficult for a first timer. I like the way you set this up so you can visualize where the neck needs to be, so first rule is DO NOT TOUCHT THE DOVETAIL UNTIL YOU GET THE NECK ANGLE>
so the way you shimmed the heel you can see how the neck heel has to me manipulated to get the proper angle. Also this is not M&T this is a dovetail joint.
so work in small increments and take your time. Feel free to call me I can walk you through the process
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
tippie53
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Re: The Dreaded M&T Neck Joint

Post by tippie53 »

John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
johnnparchem
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Re: The Dreaded M&T Neck Joint

Post by johnnparchem »

Dobroguy wrote:Thanks for all the replies everyone. Your insight is much appreciated. John my guitar has a dove tail joint. This is my first dove tail experience. After sleeping on my dilemma last night I watched the BCG neck setting addendum video and the light came on. I didn't chamfer the neck block edge enough at first, which prevented the heel from moving into proper position. After chamfering it a little more my neck settled right down properly and it looks like everything is perfect at this point. I'm now confident enough to lower the neck into position.
I am very confused by your pictures. The neck looks over set by more than 1/4". I do not understand why you have the bridge elevated on the top to match the 1/4" the neck is out of the joint. Your setup does not appear to anticipate that there will also be a 1/4" thick fret board on the neck. Even with a fretboard with frets the spacing over the bridge you are trying to achieve is high.
tippie53
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Re: The Dreaded M&T Neck Joint

Post by tippie53 »

he has it right
he has a spacer at the neck and another at the saddle point of the same height, look at the heel as he has that shimmed so he can visualize the neck angle with the bridge.
The dovetail has it set high and he is using the height in the block before he proceeds. Now that he can see where the fretboard plane will be , he can see how the heel on the neck must be trimmed to achieve this plane .
Now he has to work the heel cheeks to set the neck to that angle. Where most people miss is they start working the heel and as the dovetail joint changes in relation to that neck angle they start working the neck tenon. I suggest to just shim the tenon until that neck angle is achieved , then work the tenon.
Look at it this way
The heel cheeks control the angle and center line. Once that is established , the tenon will control the elevation and the twist of the neck so do only adjustments on one plane at a time and you will be able to control the set easier.
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
tippie53
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Joined: Fri Mar 03, 2006 7:09 pm
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Re: The Dreaded M&T Neck Joint

Post by tippie53 »

John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
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