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So I’ve done more than a few guitars w this jig.. It does work well once you get the body set in the jig right, however there’s an issue: and maybe I’m just doing it wrong so please help.

When you place the body in the jig and tighten the thing up how does one keep the body perpendicular with where the tenon will be cut.

In other words; how do I make sure that the clamp of the jig is holding the body perfectly perpendicular to the top so that the mortis isn’t at an angle?

This is more more challenging to explain than I thought it would be.

B


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Keep in mind, I have one of these in the mail so I haven't used it yet. But I feel like the video's did enough for me to get the understanding of how it works. Also, I've done all my guitars without any jigs to this point. I cut my mortise in the head block before gluing it in and then cut open the mortise after the body is closed and then cut and align the neck and tennon.

I say all that to say, it's still the same process but without the help of the jig, so I think I can offer some useful comments.

The mortise bottom (like in virtually any furniture joint) is more or less irrelevant. So, if the back curve of your guitar is pushing the tail of the guitar slightly "forward" or away from the jig, your mortise will end up ramping up a little toward the back of the guitar. But, like I said the bottom doesn't really do anything since you don't ever want your tennon end touching the bottom of the mortise. When you flip the jig to do the neck, you'll set the body on its flat mortise surface, perfectly perpendicular to the table top of the jig and then set your neck angle, which Is really the only thing that matters.

Of course I say the mortise bottom is irrelevant, but certainly you can't go too deep or it will weaken the wall of the head block where the bolts connect. But, I always end up with about a 1/16" or so gap, and I doubt any of my tennon ends are perfectly parallel to the bottom of the mortise... but again, it doesn't matter.

I agree this stuff is hard to explain, but hopefully that will help.

At least you have videos to work with. https://www.youtube.com/watch?v=aWtAy5vS6gA

I have the Luthier Tool neck jig. Absolutely love it. But no videos.

But I agree. The mortise is the easiest part. On my jig, there is just an end vise. Put guitar in a large vise and make the cut. You just want that cut to be centered and straight.

Ok so if you let
The video you posted play for just a few seconds you see the two knobs on the front.
What I’m saying is ... if you don’t have those 2 knobs tightened exactly the same, then the back part that those knobs move will be at an angle and cause your body to sit at an angle


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You’ll like the jig:) I’ve done 17 guitars with it so far.
I’m just wanting to get this one detail dialed in


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I built my own from Robbie OBrien's plans, but it's the same thing. What I did was cut slots instead of just round holes for the two clamping rods to pass through--this allows the jaw to swivel slightly. To use it, I hold the guitar body tight and flat against the top where the template is, then tighten the jaw. It will swivel to an angle on the back that keeps the body square to the jig.

Dave

Ahhh yes. I see. Different axis than what I was describing. That will need to be resolved to be useful.

OK, I see what you mean. What is needed is a centerline finder (looking down from top through the template). I guess you just have to eyeball it? With my LT end vice, there are two adjustable dogs and two twist knobs. http://www.luthiertool.com/edge_vise.html. See the pic with the vise and centering template. Thats what I mean.