What most stumps you in building?

[tippie53]

I had a statement about the plane of the neck being about 1/8 in off the top

Ok lets try and make this as clear as I can. I know that I do this almost daily and it is such a part of what I do , I hardly even think about it but it I can explain it , I will sure try.

Lets address a few basic parts for clarity to this discussion.

A neck pre set
Setting a neck without a fret board attached to the neck.

B Neck block position
Measuring the height of the neck , off the top at the point of the neck block where the rim and the neck meet. In most cases , the point of the 12 or 14th fret , or the connecting point of the fretboard.

C saddle position
This is where the saddle would be measured off the point on the neck where the nut is located , so this would be based off the scale length you are using.

D neck plane
this is the top of the neck where the fretboard is attached.

E Center line

There are 2 center lines we are working to , One is the one off the neck and then the fret board the 2nd is the top. We will set the bridge on the top to the center line off the neck.

F Clearance from holding off
chamfer or bevel the edges of the sides where they open to the neck block. The male/female corners have to be cleared . The sides , if left sharp may fit into the corner of the neck and that interferes with the mating surface of the mortise and tenon. This is one thing that can really make a mess out of the neck.


OK Lets get started. When you start to do the PRE SET of the neck , this is done as the body is in the white just as you close the box. We want to get the neck set so when we are done with the finish process we will attach the neck after the finishing . I don't finish the neck on the body but will do them apart and then attach them . So let us assume we are doing a raw neck that has just out of the box.

You will need a good measuring device , I use a 36 in scale, and it has a straight edge. I also use a smaller scale so I can measure the top and the neck plane.
Also some wide tape.

We start with the neck in the block. I clamp it tight so I can measure the neck center line to the top center line. I also measure how how the neck is out of the block. So please for sake of discussion we will call this at this point 1/8 in.

This is an example of what I may see as I am setting a neck. You will have to adjust a bit to what you acutally have but I hope this will clarify some of the discrepancy in the past posts.

Here We Go

The neck is clamped in , I measure the neck at the block along the rim of the guitar and see a 1/8 in rise. I then mark the point of the nut line on the neck. This is just a general point. If I am within an 1/8 we will be close enough for this exercise. I lay out a piece of tape in the area of the saddle. Let us assume that we are doing a martin long scale ( 25.4) So I now have
A neck at 1/8 about the rim
B point of the saddle ( 25.5) make it easy
C laying the straight edge on the neck I see that the neck is 1/8 off the top at the point of the saddle.
D Center line off the neck measured at the tail end of the guitar is 1/4 in to the bass side.

What does this mean ?
This neck in this situation is dipping down and needs to be adjusted so we raise the neck to get the proper neck angle , and also the neck is canted to the bass side and will have to have the heel adjusted to swing the center line of the neck in more of a line with the center line of the top. This is done by removing wood all along the heel do let the neck swing. NOTE: this is needed on any neck and the joining method doesn't matter.

So what must we do?

There are a few things that we have to do and the most important is start by taking a pencil and marking the lines of the heel at the neck joint. Most Martin style kits will have a neck block that has a slight radius on it. So mating a flat heel cheek off the neck to the radiused neck block can be problematic , so I will flatten this area. Now to mate a flat to a flat is much easier.
Next I will make a few hash lines on the neck heel as a reference line so I know how to work my neck heel in adjusting the fit , angle and center line,

Now with the mating area flattened we can start making adjustments to the neck . DO NOT TOUCH THE DOVE TAIL
So using the hash marks , you want to adjust the neck angle first. In the back of your mind you know that the bass side of the neck heel will also need adjusting later but for now just do one thing at a time. Trying to do too much can cause you more confusion.
Using the lines ( I usually do 5) work the heel down. In my video you will see that I do this with a sanding block. Also NOTE: that this is about a 5 to 1 move. If we need to move this neck angle up 1/8 in. That is .125 so you don't want to take more than .025 in . WORK IN SMALL INCREMENTS .
So you want to only work the first 3 to 4 hash marks. Work both sides. CLAMP IN THE NECK and look close at the joint so you have the neck tight as you can to the body. You may see a slight opening up near the top but as you get the neck heel adjusted this will close up. This is a constant work the joint and test the fit and measure. As you see the neck angle working up , always be aware of the difference of the height from the neck joint to the saddle position.
so after a few tests you have the neck at
A 1/16 in and the height off the point of the saddle at 5/32
this is a difference of 1/16 = ( 2/32 ) that leaves a 3/32 rise at the point of the saddle
If you are between 1/16 and 1/8 in you are within the spec for this pre set.

So you have the neck angle.

Now you need the center line.
So lets say you now check the center line of the neck to the top and you see that you now have 5/16 off to the treble side.

You may be thinking What the Hell did I do now

Relax , this is a result of you working the heel and one side may have more wood removed than the other side.
As someone said this is the joint from heel , I would say that this is a joint that makes you scratch your head. So now you have to make the neck swing to bring the center lines together. I would say that if you are within 1/8 in to the center line of the top at the tail block you are fine.
NOTE:
When you look at the heel and how this adjusts the center line , the distance off the heel from the neck center line may only be about 1 1/8 in , and the distance from the neck heel to the tail is about a 20 in distance , this will make the move ratio about 19 to 1. So 5/16 in is .3125 and you want to move this back to center and you are leaning to the treble side you will want to take off only 1/19 off this 5/16. That would be about .016. this is not much .
Most issues with this joint are often caused from over adjusting. Also keep in mind that joint must be tight for taking measurements
NOTE: if the neck feels loose DON"T TOUCH THE DOVETAIL but USE PAPER AS A SHIM AT THIS POINT>
by using the paper shims , you are not changing the physical dovetail joint yet. You can add paper easier than removing wood. You can also put more on the bottom than the top. THE POINT IS TO GET THE JOINT CLAMPED TIGHT!

ok you now have the basic tools for adjusting this neck. You have now adjust
A and C of the ACE equation
A angle
C center lin

Now with all this you can use a strip of sand paper and floss the heel at the body to clean up the fit.
NOTE: once the angle and center line are established you no longer need to touch the heel of the neck. This is the plane that locates the heel.

OK now we do E of ACE Elevation.

I use chalk but you can also use carbon paper

So with chalk mark up the neck block where the neck tenon will fit in the mortise . Now carefully set the neck in the block and clamp.
NOTE: the lower part of the tenon is what you want to see covered in chalk. THIS IS A PINCH JOINT.

NEVER WORK IN THE NECK BLOCK.

Once you pull out the neck look to see where the chalk is and just remove that. It won't take you long to see how this works. VERY SMALL ADJUSTMENTS ARE NEEDED.

If your neck fits below the top you will need a shim .

So lets recap

HEEL
this makes the adjustments of the neck. Look at the neck and just think about the mating surfaces and the relationship to how the neck would move by adding or subtracting material. This is the whole crux of the neck setting procedure.
The tenon is the part that locks the joint together.
NOTE:
the angle of the tenon , in relation to the mortise is critical to understand. Look and this in the block and you can see that the "sway" of the dovetail locks into the neck block. You want the tenon to be parallel to the mating mortise. In reality you can even make it a bit more angled so the lower part of the neck tenon sets into the neck block. If you flatten the angle you will loose this pinch and bind of the mechanics of the joint. This is where the neck joint can really frustrate the heck out of you.
Please let me know if any of this need clarification.

On a side note to this

I also stated about screwing in the neck block.
Let me say that the neck block should be set into the rim so the mortise is square and centered to the body. Also before you screw the neck block to the mold , you drill a 1/4 in hole through the mold. I use a screw that would be about 1/4 in short of the mold and neck block so I don't make the screw protrude through the neck block.
I set the block to the mold with clamps and then using a washer and the screw lock the neck block into the mold. Remove the clamp and the screw will hold the neck block. I then apply the spreader.

If you get the neck block in off center or square , you can make some adjustments to the neck tenon. To accommodate a tilt in the neck block you will have to adjust the tenon by taking some off the top on one side and some off the bottom on the other.
If you are off center , you can always remove more off the tight side to move the neck over .

[JLT]

What stumps me most? Well, right now, it's keeping my darn hands off two instruments I've just applied lacquer to for the couple of weeks the finish will need to cure. I don't know if there's an answer for that one.

[B. Howard]

What stumps me most? Well, right now, it's keeping my darn hands off two instruments I've just applied lacquer to for the couple of weeks the finish will need to cure. I don't know if there's an answer for that one.

Yes, it's called starting your next build......
;-)

[songman101]

Hello John H.

I appreciate the videos very much. This was my 3rd viewing an I'm getting a firm hold of the operations to setting the neck. I am close to starting my 1st build (I'll post it ) and this is a great source of knowledge. Thanks john H. and also thanks to the others who share their talents.

The new newbie Stephen C. songman101

[Darryl Young]

I use bolt-on joints cause it is easier. The flip side is I had to tighten the bolts on nearly every guitar within 18 months, even though I use the springy washers.

I've had this happen initially as well (though it seems to be stabilizing over time). I think it's because the wood in the neck block compresses over time due to pressure from the bolt. I guess a large flat washer would help (have to compress more area). I've also considered countersinking the flat washer then using thin CA glue on the wood in that countersunk hole thinking that might help prevent compression (at least on mahogany neck blocks).

Maybe using a species other than mahogany could help prevent compression (though their may be other tradeoffs like addition weight or less stablity). Maybe making your own plywood using mahogany at the center (for stability) with caps on front/back of a harder, stable wood that doesn't compress easily would be the answer. Maybe run the grain the same as the sides where it will be glued to the sides.

Martin uses a plywood neck block on some lower end models so it can work. I think Mario Proulx uses a ply made of spruce layers for the neck block on models where he wants to save weight (like when using Cocobolo and the guitar is already on the heavy side).

[Darryl Young]

Finishing is my Achilles heel.......I should just bite the big one and send mine out for finishing work. It would make the process much more enjoyable for me......and my asthema would appreciate it as well.

[tippie53]

we can chat about that also

[Mitch]

Finishing is my Achilles heel.......

Darryl, have you tried french polish? It's pretty much foolproof. Yes it smells like vodka, but there's no sanding of the finish, so dust is a minimum. I didn't fill the grain, since I like the look and texture of real wood. The amber color of the shellac also makes rosewood warm and rich.

Mitch