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While waiting on finish to dry on No. 1, I decided to get back to work on No. 2. I have been setting the neck angle, which as it turns out is in even worse condition on this one than it was on No. 1. But, while shaving the heel to adjust the angle, I got to a point where the tenon is now bottoming out in the mortise.

It would be easy enough to make the tenon shorter, except I have already installed the truss rod and both threaded inserts are super glued in place.

So what is the best way to proceed from here? Find a way to cut the mortise deeper? Add shims under the heel? Other suggestions?

Thanks,

_________________
Phil

http://www.oleninstruments.com

"Those who tilt at windmills are only considered insane by those who can't see the dragon."

Phil,
Don't fret, there is always a solution.
How long is too long?
Tom

Can you post a photo of the neck tenon and the body mortise?
The same has happened to me and I simply deepen the mortise with a sharp chisel. As long as your bolts don't bottom out that should work. And you can always shorten the bolts on a grinder or sander.


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"It is easier to fool a man, than it is to convince him that he has been fooled"
Mark Twain

A disk sander makes short work of trimming a tenon when the fretboard is already installed...the final trimming close to the extension can be done with a sharp chisel.

_________________
A constellation only takes shape when one maps the whole.
- Beth Brower

Yep, deepen the mortise by 1/16".

Is deepen even a word?

Deepen the mortise with a sharp chisel, assuming there wil be enough material left.

That's what I just did on my last after fighting with the neck angle too.

_________________
I'm not a luthier.
I'm just a guy who builds guitars in his basement.
It's better than playing golf.

You can easily deepen the mortise with a top bearing short flush cutting router bit.

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

Thanks for the help. I'll get that cut deeper somehow, and make it work. Somehow. And I'm glad I'm not the first to have this problem, though I wouldn't wish it on anyone.

One of these days I'm going to make one where I don't mess it up as I go. Or am I dreaming again?

_________________
Phil

http://www.oleninstruments.com

"Those who tilt at windmills are only considered insane by those who can't see the dragon."

Ĺol
I have shortened the tenon with a chisel very easily. Although......... I had to do it a second time...gah.... and ran into the inserts. However, I just filed them down a little.

_________________
Pat

I guess deepen is a word.

You certainly aren't the only one and I personally wouldn't even categorise this as "messing up". Encountering this situation myself taught me that machining the neck m+t joint to fit precisely in all dimensions requires complete control over final neck geometry long before the stage of final assembly. I get close, but not close enough to trust myself to machine the m+t to fit with absolutely zero clearance earlier in the build process. Snug fit is nice, and desirable but less important than with a glued joint since you're using bolts.

I've always had to at least slightly adjust the neck pitch or yaw during final assembly. This is not uncommon - you'll notice that almost every book that describes m+t neck joint construction includes a section on flossing or trimming the heel to get things lined up right. If your mortise is at precise depth, you cannot remove any material from the heel cheeks to correct neck alignment.

So you have not made a mistake, you are simply engaging in a time-honoured tradition of the craft

I opt instead to simply make the mortise slightly oversize in this dimension from the get-go. This means there is always a slight gap between the end of the tenon and the bottom of the mortise This is not a problem since it is the 'cheeks' of the heel which bear the load when the bolts are tightened.