Official Luthiers Forum!

Peghead or sound-hole? I've been thinking about this and I really prefer the headstock access. My reasoning is that cutting the hole in the transverse bar weakens the brace where strength is of utmost importance. Every Martin needs a neck reset, it's just a matter of time. Is this true of Gibson's and other peghead access guitars? I feel like that brace should be taller than the plans I have if I'm going to put a hole in it.

My next guitar will probably have access in the peghead and be a bolt on neck.

_________________
Hutch

Get the heck off the couch and go build a guitar!!!!

As a repair guy I advocate for peghead. I hate having the pull the neck to adjust the truss rod multiple times on all those Fenderish setups. Leo messed up when he went there.... Of course, he's the same guy who made the neck removeable so it could be thrown away...

_________________
"Act your age, not your shoe size" - Prince

Pick your weakness. A small hole in a brace or a 1/4 trough continued through the neck? I haven’t heard of a broken utb from a hole.

I build both. On guitars with no access to the neck block (archtops, guitars with f-holes...) I do the Gibson style route. On slot heads I pretty much have to put in it the sound hole. Others I do what I think is right for that particular style of guitar.

If I do a Gibson style I always made a scarf joined head so I've somewhat eliminated the weak grain direction (I do scarfs on everything actually). I use truss rods with allen adjusters so the route is as small as possible. I always put a headplate on and occassionally a back strap.

And I never leave my guitars sitting out on stands where they can fall off and break.

if you want a broken headstock go with the head I put them inside . I 22 years of repair I have not seen 1 transverse brace break from the hole
I have seen then from pissed off girlfriend putting high heels and hammers through the top though

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Soundhole for me, with a hole in the UTB. No prob.

I mostly use rods installed for soundhole adjustment, but I don't drill through the transverse brace. The rod stops at the neck block, and is adjusted by reaching behind the brace using the short leg of a standard Allen wrench.
With the advent of Allen adjustment nuts, it is a mystery to me why most of those headstock truss rods still have hex nuts, which require a large cutout in the weakest part of the neck to clear a socket wrench. With a recessed Allen nut, the peghead access hole only needs to be large enough to accept the Allen wrench.
OTOH, repairing broken headstocks does add to my income, so why complain?

_________________
John

I don’t see much problem putting a small hole in the UTB. It is not a notch; it is closed on top and bottom. We put caps over the x brace lap joint for this and rationale. Having that skin on top and bottom captures most of the streangth of the brace. Even though we glue the x brace together, those are partly endgrain joints. Once capped we don’t stress about the weak spot in the middle, and those braces are much narrower and shorter than an UTB.

_________________
Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Maybe that's what is needed on the UTB to strengthen it after the hole is cut. I firmly believe this is a weak point and part of the reason for neck resets. The wood will stretch over time and the time is shortened by that hole. Has anyone experimented on this or are we just following standard Martin practices? Now that I think of it, this information is probably well documented somewhere. There are probably limits to cutting holes in floor joists. I'll do some research.

_________________
Hutch

Get the heck off the couch and go build a guitar!!!!

I don't see excess top sinkage on those guitars with a drilled UTB. Consider that the hole is bridged on the top side by the top and the fingerboard.
Martin used a 5/16" wide UTB until mid-1939 ( and no popsicle), and those guitars do tend to sink in the upper bout more than the subsequent guitars with a 1/2" UTB plus the popsicle. But IMHO, the major reason for needing a reset lies in the bellying up of the bridge area.
If you feel it is really necessary, you can beef up the UTB by simply making it a little taller, and/or using a stiffer wood (i. e. a hardwood), either for the entire brace, or by using a vertical lamination between two spruce layers.
I prefer to arch the UTB slightly to counter the tendency to sink.
I do select the spruce for superior stiffness.

_________________
John

I bring this up because of the Yamaha reset I just completed. A straight edge from upper bout to upper bout clearly showed at least 1/8+, I didn't measure it, sinkage. I wish I had studied the construction more but I had gotten frustrated with the job and just wanted it gone. One other thing that isn't done on Martins is the top and any structure that was preventing this sinking, was carved out to allow the truss rod to drop in when installing the neck. So that design definitely allowed this to happen. I know we're talking apples and oranges but it still worries me to do anything that would weaken that area.

_________________
Hutch

Get the heck off the couch and go build a guitar!!!!

One more thing. Pegheads are easier to fix than sunken tops and they don't have much affect on tone and volume.

_________________
Hutch

Get the heck off the couch and go build a guitar!!!!

If the neck-access truss rod pocket and hole in the UTB cause the top to sink then I think the guitar was constructed poorly. The truss rod slot in the neck is not big enough to be a mechanical issue and the hole in the UTB, if done properly, is in a non-critical area from an engineering perspective.

_________________
Steve Smith
"Music is what feelings sound like"

My ability to maintain strongly held beliefs despite overwhelming evidence that I'm wrong is something that I struggle with. Once I form an opinion, it is very hard for me to change it. Maybe all of us are just wired that way.

In this instance, I think you are drawing a broad conclusion based on a small sample size. One Yamaha doesn't tell you what is going on with most guitars.

On top of the things you have heard from some very knowledgeable people, here is another data point for you to consider: All Martins with adjustable truss rods have the adjustment happen through a hole in the UTB. Which is more likely: That Martin (a company that makes avoidance of warranty repairs a high priority) is building a significant weakness into their guitars; or that the few guitars you have noticed with upper bout sinking problems had more serious issues than a hole in the UTB? Food for thought.

Reckon this should be plenty strong enough - nylon strings - slim truss rod, volute, straight grain, 2 veneers top and 2 back.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

I ran into my first one of these yesterday. A friend brought a very nice Larrivee for a setup and commented "it doesn't seem to have a truss rod". I looked inside with an inspection mirror and sure enough, just like John described.

Relief measured 0.012, above my specs. Took the strings off at the bridge so I could get my fat hand in, tried different allen wrenches. 4mm too small, 5 too big, must be Imperial. Found that I could get the short leg of the wrench in the adjuster but couldn't turn it, not enough leverage and it would run into the back of the guitar. Fortunately my allen wrenches are ball end, with the help of a light and mirror I got it in the rod at a bit of an angle. Put an open end wrench on to act as a cheater (I hate doing that) and managed to get an eighth of a turn. Put the strings back on, tuned up and measured the relief.

It was 0.008, still more than I like but frankly that was such a hassle I said "good enough" and continued with the setup. I'm not real proud of that, I might go back today and take the strings off and give it a little more. Its kind of like working on a Fender where you have to take the neck off and guess how much to turn it. Maybe good enough if good enough.

So, short story. Its certainly possible to install a truss rod with the adjuster inside the guitar and not drill the UTB. I'll continue to drill mine.

They make special allen wrenches for that type of adjuster. But I don't have a set so I had to do the same maneuver to adjust these darn things.

I made many multi piece beams when I was a young carpenter. When there is weight on the beam (UTB) the top of the beam compresses, the bottom of the beam expands, therefore the center of the beam is neutral. Drilling a hole in the center has no effect on the strength of the beam.

Brent

Freeman...you need one of these...



You can get them from Larrivee, and the guitar was supposed to have been shipped with one. A 4mm or 5/32" Allen will do the trick though in a pinch. But don't you just wish they drilled out the UTB?

FWIW, I drill through the UTB so that folks won't need the special tool. I'm confident that the engineers that state that this step won't be problematic are correct.

Although, depending on the age of the Larrivee, it may need a 3/16"...

I see your point and I'm starting to come around to believing what everyone is saying. On the other hand, you have Gibson, and I kind of like the little cover on the headstock.

_________________
Hutch

Get the heck off the couch and go build a guitar!!!!

Well, if you were to go with a headstock truss rod adjustment, I would recommend (as Freeman does) that you use a scarf joint at the headstock instead of a one piece neck. The short grain on an angled one piece headstock, combined with a hole for the truss rod, makes a Gibson style guitar pretty prone to broken headstocks. In contrast to what I said about Martin, Gibson really does build a known weakness into its guitars (unfortunately). The repair folks can provide plenty of data on this.

The other thing for a headstock placement is to use a truss rod that adjusts with an Allen wrench. That will allow you to leave more wood in the headstock area than there is in a Gibson.

_________________
Steve Smith
"Music is what feelings sound like"

I'm aware of all this Don, but I like look and ease of adjustment, especially with an allen head on the the rod. That pocket could be really small. I also have another con for the other end of the neck, I usually mess up the strings with the side of the wrench and haven't figured out a good way to get them out of the way. With the headstock adjustment, I can adjust under full tension. That may be a bad thing but I do it.

I'm not trying to convince anyone, I haven't even convinced myself of anything. My decision will probably flip flop right up to the point of routing the slot.

_________________
Hutch

Get the heck off the couch and go build a guitar!!!!

With my last post, I wasn't trying to convince you to use a soundhole adjustment; I was just trying to recommend ways of making a headstock adjustment less of a problem. The scarf joint is a good way to strengthen the headstock, regardless of which trussrod access end you go with. Both ends are valid and reasonable, but there are tweaks to each that can make them more or less of a good idea. Scarf joints help make headstock access less of a danger. A hole in the UTB helps to make soundhole access easier, with no real downside. I've done both; both are fine. Right now, I prefer soundhole adjustment.