This is a semi carved and a pre carved neck available from LMI.
The pre carved neck is already carved to shape.
The semi carved neck only needs a rasp or a spokeshave to finish to final shape.
Using these necks is a great way to ease into neck carving
and a surefire way to personalize your guitar for ultimate playing comfort.
These necks are made from quality quartersawn mahogany
and come with an oversized peghead which allows the builder
to customize the peghead thickness and shape as well as the scale length.
The necks are made to be used with the popular scale lengths 25.4 and 25.5
However my thicknessing the oversized peghead from the frontside
you can use it to accommodate a 24.9 scale as well.
The heel blocks use a straight mortise and tenon neck joint
and are pre-drilled and come with all hardware needed for installation.
The necks and blocks are deep enough to accommodate deeper style guitars
and can also be trimmed to fit thinner body styles as well.
The truss rods slots are pre cut to accommodate the LMI double action truss rod.
You can access the truss rod from either end of the neck.
Now let me show you how I install these necks in my shop.
I am going to be demonstrating how to install the LMI semi-carved neck on one of my guitars.
However, the installation process for the pre-carved neck is virtually the same.
The first thing I need to do is prepare this heel block.
And since I am going to be building a cutaway guitar
I need to prepare the side that the cutaway is going to glue to.
When you glue your block in, since the holes are pre drilled in both the tenon
and the mortise it is extremely important that that lines up with the centerline of your form.
Once the block and sides are glued together you can now build your guitar up to the point
when you are ready to attach the neck making sure that the centerline of that block
stays aligned with the centerline of your form.
As I am building my guitar, one of the things I need to do
before the neck can be attached is to thickness the peghead.
This is too thick. By the time I get my veneers on there
it is going to be too thick to receive the tuners.
Right now this is coming in at 15mm thick.
These are approx. 4mm, that is 19mm The post of the tuner
wouldn’t be able to come up enough for the nut of the screw to grab it.
So, I’ve got a problem. I need to thickness this.
If I thickness it from the top side,
I am going to alter my scale length because this is going to be moved back.
So, I am locked in to having to thickness from the back side.
So, let me show you how I do that. I am going to come in with a marking gauge.
I’ve got it set up for 11mm.
I am going to do that from both sides.
So, the next step that I am going to do is glue the peghead veneers to this surface.
The first veneer goes over the top making sure that I have enough overhanging
and then I am going to butter up the veneer with my LMI instrument makers glue
and once again get out my high tech glue spreading device.
Make sure that you use a clamping caul on the back side of the peghead
because that is a finished product now
and if you mar up that finish with your clamps the technical term for that is bad.
You can now come in and shape the peghead using your preferred method.
So, I built the guitar all the way up to the point when it is ready to attach the neck.
The neck is bolted on there. It is flush here. It is flush here.
Now the next thing I need to do is check the neck angle.
On my guitars I like to see a gap of 3.5mm and right now I’ve got a gap of 2mm.
So, I need to remove just a little bit on this side of the shoulders of the tenon.
That way the neck will tilt just enough.
And you want to take the same number of strokes on each side.
So, I spent some quality time with my hand plane bringing down the shoulders only on this end.
I didn’t touch this end. Here is another little trick you can do.
Come in and turn your chisel at an angle and relieve some of that in there.
This is gonna help us in our next step.
Now a lot of these steps I am doing are pretty advanced steps.
If you want to learn more about this you can check out my online course
at obrienguitars.com and I show how to so this in detail.
Alright, let’s see if we got the 3.5mm gap.
So with the neck bolted on and the straightedge extended all the way back to the saddle location,
I’ve got a gap of exactly 3.5mm So, there is one last step to do.
I have the correct angle but I need to know if my neck is on the centerline.
The way I am going to check that is down here on this end I’ve got a centerline.
I ‘ve got a centerline here, and I am going to place it on there like that.
So if I look at this end of the straight edge,
it is aligned with the centerline at the 14th fret and the butt end of the guitar,
you can see that my ruler is just a little bit off centerline.
So, there is a little trick you can do to adjust the centerline on that neck
by swinging it a little bit right or a little bit left
and it doesn’t take much to swing that neck over.
This flossing trick also works well if you have any small gaps or things in there.
It will help sand this to the shape of this.
The depth of the neck is made so that you can do thicker body guitars
as well as thinner body guitars. To do a thinner body guitar all you need to do is just
shave off some of the depth of the neck there.
So, I’ve cut this off at an angle, right flush with my binding there.
And once I place it on there, there it is.
The neck can now be bolted on and you can continue building your guitar.
So, the next step I have done here is just slotted my fretboard
and tapered it so that it matched the widths of my neck.
My fretboard matches perfectly the profile of the neck.
I’ve got it pinned so that it won’t skate around when I glue it.
Also, don’t forget to put your truss rod in there. It’s a real bummer when that happens.
I had a friend once that that happened to.
My next step is to carve the neck. This is a semi-carved neck available from LMI
and it is already pretty close to specs so all I need to do is finish it up.
Then I am going to level and radius my fretboard, pound in some frets
and then I am in to finish work.