If I may... would like to question the experts regarding truss

[mistermikev]

Not as impossible to understand as you might think.

I've mocked-up the action on several guitars in-process of building. I set a nut at the end of the fret board, used an elastic string all the way to the bridge, then fretted the string at the first fret. The whole action lowered by a significant amount.

With angles, a little at the start (nut or first fret) vectors into a lot at the other end.

I shoot for "two business cad" depth from the bottom of the string to the top of the first fret, or .013-.018 between them.

That's what I call "low, but not buzzy".

I take a lot of time in setting this stuff up. Ideally, I want my bridge to be on the deck and the strings just touching the 22nd fret. I don't favor high-in-the-sky bridges.

A forum member here sent me his SG for a neck reset. That thing had a neck angle of 4.55 degrees! That's no lie.

WAY too high. This is from the factory. 2013 SG. The bridge pup was practically out of it's ring to get high enough to the strings. Bridge was way jacked-up to get the strings to clear. IT was like playing a damn cello.

This was NOT right. No way. So I pulled the neck, repaired the angle to give it 2.5 degrees.

All worked out perfect after that.

lots of good thoughts there thank you very much for the reply!

so far have only done one tom bridge... I had mocked everything up in photoshop... planned out my 4.5deg (I actually chose 4.5 deg based on the layout and how everything sat)... used actual height from gotoh bridge... actual height from the frets I bought... proposed ending thickness of my top/body... fully planning to try to arrive with my bridge height screws literally touching the body... but then chickened out and raised it 1mm so that i'd have someplace to go if things didn't work out lol!
Looking at that guitar right now... by eye looks like I have 1mm. next time I'll not second guess myself - can always cut the slots in the saddles lower. i don't know if the gotoh tom bridge is taller than typical lp but i don't think so. As I recall... i lowered the neck into the body based on what i saw and considering this is a baritone, so wanted to bring that headstock as close as possible. long story long... wasn't held to any specific neck dimensions so it seemed like the angle there is rather arbitrary if you are willing to adjust other things to fit it. laugh all you want but it's comfy as hell i swear!!

cello - lol. interesting that there is that much difference (2 degrees) for that setup. I wouldn't have guessed that and it is now on my radar to lookout for as I approach doing a similar layout in photoshop for the 24.625 scale.

 

[CB91710]

A forum member here sent me his SG for a neck reset. That thing had a neck angle of 4.55 degrees! That's no lie.

WAY too high. This is from the factory. 2013 SG. The bridge pup was practically out of it's ring to get high enough to the strings. Bridge was way jacked-up to get the strings to clear. IT was like playing a damn cello.

This was NOT right. No way. So I pulled the neck, repaired the angle to give it 2.5 degrees.

That that 2013 wasn't the only one Gibson made.
They still made them that way in 2020....

P90, but the same problem.

 

[CB91710]

planned out my 4.5deg (I actually chose 4.5 deg based on the layout and how everything sat)

4.5 deg works with an arch top like a jazz box or a Les Paul.
It is too much for a flat-top like an SG or Fender.

Especially a Fender, where you don't have a lot of room to adjust the saddles to begin with.
But they have bolt-on necks and it is easy to shim them to get the desired saddle height.

 

[mistermikev]

 

[mistermikev]

4.5 deg works with an arch top like a jazz box or a Les Paul.
It is too much for a flat-top like an SG or Fender.

Especially a Fender, where you don't have a lot of room to adjust the saddles to begin with.
But they have bolt-on necks and it is easy to shim them to get the desired saddle height.

don't they cut the angle into the top of the sg too? I thought it had a slope there but honestly idk... haven't looked that far into one. my mistake... i guess that explains that.

 

[CB91710]

don't they cut the angle into the top of the sg too? I thought it had a slope there but honestly idk... haven't looked that far into one. my mistake... i guess that explains that.

The SG body is a simple slab like a Fender, with a chamfer around the perimeter to give the body some dimensional depth.
The bridge mounts to the body in the same horizontal plane as the pickups and top of the neck pocket.

 

[mistermikev]

The SG body is a simple slab like a Fender, with a chamfer around the perimeter to give the body some dimensional depth.
The bridge mounts to the body in the same horizontal plane as the pickups and top of the neck pocket.

View attachment 575834

right on... I've owned an sg and just never really even thought about it. thanks for the clarification.

 

[cmjohnson]

As I recall, an SG has a neck set angle of about 1.5 degrees. When I build a singlecut style guitar, my neck set angle is about 3.5 degrees, and for a carve top double cutaway (PRS style), it's 2.4 degrees, more or less.

In the case of the PRS type, I established that angle by directly measuring a PRS body section I got from someone who used to work at PRS. Just for giggles, if I had managed to obtain four similar design quadrant cutoffs of PRS rejects, I would have taken all four chunks and rebuilt them into a single guitar made from all four. I'm still three quadrants away from completing that mission, as I have no current PRS connections.

I think it'd be amusing to build such a guitar. The northwest, northeast, southwest, and southeast quadrants would all have nice figured maple tops, but none would match. And to complete it, dye stain each quadrant a different color. Have some fun with the fact that it'd be made from pieces of bandsaw cut rejected guitar bodies.

But, back to neck angles....to me 4.5 degrees is too much angle. That'd be OK for a violin or a cello but on a guitar it just looks odd. It'd have you setting up a TOM style bridge sitting up high on its posts.

Pick your hardware style, your bridge and tailpiece in particular, and do a full scale drawing of the proposed guitar as if you cut it lengthwise right down the middle, giving an elevation map. Be precise about every measurement. WIth this full scale, and presumably accurate elevation plot, you can now easily work out your desired neck angle. Which is mostly going to depend on your top carve profile. Hardware clearance is the second most important factor.

As a rule of thumb, an LP/singlecut style with a 5/8" thick top and a TOM bridge is going to give you a 3.5 to 4 degree neck set angle. A PRS style doublecut with a low profile bridge, 2.4 degrees will be typical. A guitar with a flat top will run between 0 and 1.5 degrees. You don't NEED a set angle with a flat top. You can angle it if you want but you'll start running into excessive bridge height issues above 2 degrees.

 

[LtDave32]

That that 2013 wasn't the only one Gibson made.
They still made them that way in 2020....

P90, but the same problem.

View attachment 575827

ay-yi-yi, Rich.. dats a lotta angle..

 

[LtDave32]

View attachment 575828

Sweet n' low.. Love it.

 

[LtDave32]

4.5 deg works with an arch top like a jazz box or a Les Paul.
It is too much for a flat-top like an SG or Fender.

Especially a Fender, where you don't have a lot of room to adjust the saddles to begin with.
But they have bolt-on necks and it is easy to shim them to get the desired saddle height.

It all boils down to several factors. On Fenders, note how close the strings are to the body, regardless of anything else.

For such guitars with no neck angle (Fender, Rickenbacker) It is a factor of the neck pocket depth, the thickness of the tenon. Rics have their tenon with a section cut out, and this mates against the underside of the top. This leaves a small portion of the neck and the fret board proud of the top surface. The pickups are surface-mounted, so they need the strings to be about 3/4" off the deck, as the surface-mount pup is 5/8" tall.

Fenders are another matter entirely, with virtually all of them sharing a one-inch thickness at the heel from top of fret board to back of heel. These are set in a 5/8" deep neck pocket. This leaves the strings 3/8 off the deck, and why they have that low profile bridge.

But then we run into Gibsons, Gretsches, PRS, etc. They all have angled necks.

Factors determining exactly what angle depend on several things; height of fret board, how tall the frets are, and also where the neck joins the body. All will require different neck angles. Some share a common angle, some others do not.

And it takes just the tiniest bit of difference to change the whole thing. You may have a "just right" situation with a fret board that's .220, bridge nice and low, etc. But you change that fret board out to one that's better than 1/4" thick, and now you've got things too damn high, and you change the neck angle to compensate.

Plane down that FB to the .220 the geometry needs, and all is good again.

But let's say you don't. You run with the thicker board. Then you'll have to steepen the angle significantly to get the strings and bridge back down to "sane".

I"ve got two Apaches ready for paint, and grain-filling one of them just today. One has a slightly thicker board. Same guitar, but one has a 2.2 neck angle, and one has a 2.6 angle. Purely because of the thicker fret board. And it's not much thicker. Looks normal. but that little bit of diff, makes all the diff is my point.

This is why on guitars I haven't already built, I mock them up. Even with the good math I use, there's that odd little thing that comes around. I'd rather it come around on a mock-up with junk wood than the expensive finished product.

And for you, Rich.. I've never made an Explorer. Made damn-near everything else, but one hasn't crossed my bench until your order from DSG. So guess what I'll be doing with a glue-up of soft pine from Home Depot.

 

[LtDave32]

lots of good thoughts there thank you very much for the reply!

so far have only done one tom bridge... I had mocked everything up in photoshop... planned out my 4.5deg (I actually chose 4.5 deg based on the layout and how everything sat)... used actual height from gotoh bridge... actual height from the frets I bought... proposed ending thickness of my top/body... fully planning to try to arrive with my bridge height screws literally touching the body... but then chickened out and raised it 1mm so that i'd have someplace to go if things didn't work out lol!
Looking at that guitar right now... by eye looks like I have 1mm. next time I'll not second guess myself - can always cut the slots in the saddles lower. i don't know if the gotoh tom bridge is taller than typical lp but i don't think so. As I recall... i lowered the neck into the body based on what i saw and considering this is a baritone, so wanted to bring that headstock as close as possible. long story long... wasn't held to any specific neck dimensions so it seemed like the angle there is rather arbitrary if you are willing to adjust other things to fit it. laugh all you want but it's comfy as hell i swear!!

View attachment 575825


View attachment 575826


cello - lol. interesting that there is that much difference (2 degrees) for that setup. I wouldn't have guessed that and it is now on my radar to lookout for as I approach doing a similar layout in photoshop for the 24.625 scale.

If you get it all figured out, if you lay a long straight edge along the neck and to over the bridge area, you should have no less than 5/8 and no more than 3/4 from the top of the body to the underside of the ruler edge.

Kinda better to make it 5/8, as 3/4 makes for a tall bridge setting.

 

[mistermikev]

As I recall, an SG has a neck set angle of about 1.5 degrees. When I build a singlecut style guitar, my neck set angle is about 3.5 degrees, and for a carve top double cutaway (PRS style), it's 2.4 degrees, more or less.

In the case of the PRS type, I established that angle by directly measuring a PRS body section I got from someone who used to work at PRS. Just for giggles, if I had managed to obtain four similar design quadrant cutoffs of PRS rejects, I would have taken all four chunks and rebuilt them into a single guitar made from all four. I'm still three quadrants away from completing that mission, as I have no current PRS connections.

I think it'd be amusing to build such a guitar. The northwest, northeast, southwest, and southeast quadrants would all have nice figured maple tops, but none would match. And to complete it, dye stain each quadrant a different color. Have some fun with the fact that it'd be made from pieces of bandsaw cut rejected guitar bodies.

But, back to neck angles....to me 4.5 degrees is too much angle. That'd be OK for a violin or a cello but on a guitar it just looks odd. It'd have you setting up a TOM style bridge sitting up high on its posts.

Pick your hardware style, your bridge and tailpiece in particular, and do a full scale drawing of the proposed guitar as if you cut it lengthwise right down the middle, giving an elevation map. Be precise about every measurement. WIth this full scale, and presumably accurate elevation plot, you can now easily work out your desired neck angle. Which is mostly going to depend on your top carve profile. Hardware clearance is the second most important factor.

As a rule of thumb, an LP/singlecut style with a 5/8" thick top and a TOM bridge is going to give you a 3.5 to 4 degree neck set angle. A PRS style doublecut with a low profile bridge, 2.4 degrees will be typical. A guitar with a flat top will run between 0 and 1.5 degrees. You don't NEED a set angle with a flat top. You can angle it if you want but you'll start running into excessive bridge height issues above 2 degrees.

would be amusing - 4 piece prs... would love to see that.
neck angle... 4.5degrees too much: the guitar above was 4.5deg... and the tom is sitting 1mm off the body... it could have been 0mm but I moved it up to give myself play. there was only one grade in that body - a 4.5deg grade. could probably have managed a 5.5deg angle and still have the tom on the deck... as I stated above... you could really do almost any angle(within reason and given thickness of body) here so long as you aren't constraining yourself to gibson or other specified dimensions, and still have the tom sitting right on the top.

hehe, tripping over you here - see above - my full scale drawing of aforementioned guitar shown as a cross section of neck. (it's like u r in my head!) will def do another full scale drawing of similar intent when I get closer to starting on my lp study.
thanks for the reply and input!!

 

[mistermikev]

It all boils down to several factors. On Fenders, note how close the strings are to the body, regardless of anything else.

For such guitars with no neck angle (Fender, Rickenbacker) It is a factor of the neck pocket depth, the thickness of the tenon. Rics have their tenon with a section cut out, and this mates against the underside of the top. This leaves a small portion of the neck and the fret board proud of the top surface. The pickups are surface-mounted, so they need the strings to be about 3/4" off the deck, as the surface-mount pup is 5/8" tall.

Fenders are another matter entirely, with virtually all of them sharing a one-inch thickness at the heel from top of fret board to back of heel. These are set in a 5/8" deep neck pocket. This leaves the strings 3/8 off the deck, and why they have that low profile bridge.

But then we run into Gibsons, Gretsches, PRS, etc. They all have angled necks.

Factors determining exactly what angle depend on several things; height of fret board, how tall the frets are, and also where the neck joins the body. All will require different neck angles. Some share a common angle, some others do not.

And it takes just the tiniest bit of difference to change the whole thing. You may have a "just right" situation with a fret board that's .220, bridge nice and low, etc. But you change that fret board out to one that's better than 1/4" thick, and now you've got things too damn high, and you change the neck angle to compensate.

Plane down that FB to the .220 the geometry needs, and all is good again.

But let's say you don't. You run with the thicker board. Then you'll have to steepen the angle significantly to get the strings and bridge back down to "sane".

I"ve got two Apaches ready for paint, and grain-filling one of them just today. One has a slightly thicker board. Same guitar, but one has a 2.2 neck angle, and one has a 2.6 angle. Purely because of the thicker fret board. And it's not much thicker. Looks normal. but that little bit of diff, makes all the diff is my point.

This is why on guitars I haven't already built, I mock them up. Even with the good math I use, there's that odd little thing that comes around. I'd rather it come around on a mock-up with junk wood than the expensive finished product.

And for you, Rich.. I've never made an Explorer. Made damn-near everything else, but one hasn't crossed my bench until your order from DSG. So guess what I'll be doing with a glue-up of soft pine from Home Depot.

all good thoughts here. folks will likely be asking me to stop making mockups as I am mocking up the shi%% out of things. I usually start with 10 different mockups of looks alone... just like the beatles - I figure you gotta do 10 mockups to end up with 1 that MIGHT be worthwhile. I mockup the neck angle, mockup using pictures of actual tops so I can figure how I want to orient and get the most out of the wood I have... hell I mock up the electronics. If I ever build a mocking bird I'm quite sure the universe will implode!!

going back to neck angle... on my cross section drawing... I auditioned angles from 3 to 5deg. assuming you are planing the body to the sm angle... you can pretty much choose an angle and raise/lower the neck until the string attop the fret meets the bridge at lowest height. Not trying to "tell" you anything (hehe, "as if" hope I don't come off like that) just pointing out that literally any angle constrained only by body thickness will work. It was kind of a revelation for me, as simple as it is... that this angle is really arbitrary if you are coming at it like that. admittedly it still kind of floors me... I'll shut up now.

 

[mistermikev]

You've all been very gracious in answering me and I thank you for that.
If I may - a follow up q... for those that use the gibson style truss rod - what source/rod/brand do you like?

 

[cmjohnson]

Stew-Mac actually sells a Gibson style truss rod. It's essentially identical to what Gibson uses.

Back to neck angles: Another factor not yet mentioned is the top carve itself. How thick it is at the belly vs. how thick it it is where it meets the neck. Figure this difference in thickness into the neck angle equation.

 

[mistermikev]

Stew-Mac actually sells a Gibson style truss rod. It's essentially identical to what Gibson uses.

Back to neck angles: Another factor not yet mentioned is the top carve itself. How thick it is at the belly vs. how thick it it is where it meets the neck. Figure this difference in thickness into the neck angle equation.

thanks for the vote for sm. I've seen that they have them... but tbh have been skeptical of sm ever since read there was a rash of those dual action truss rods w issues. i guess that was long ago, but has stuck in my mind. I'm sure it could happen to any mfg.

afa angle... well in my above diagram... and again doing it w/o considering gibson specs... the thickness of the top wouldn't even matter as you just are cutting in a matching angle to the neck angle... but yes, in doing an actual paul and trying to stay with their convention... def is something one has to consider. for me... I'll stick to the common 5/8 top to mitigate. thanks for mentioning.

 

[cmjohnson]

I've never bothered with the dual action truss rod that SM sells but I've used their single action kits several times, and they're just fine. Keep in mind, SM doesn't MAKE anything. They have vendors that make all their items and SM just resells them.

 

[LtDave32]

all good thoughts here. folks will likely be asking me to stop making mockups as I am mocking up the shi%% out of things. I usually start with 10 different mockups of looks alone... just like the beatles - I figure you gotta do 10 mockups to end up with 1 that MIGHT be worthwhile. I mockup the neck angle, mockup using pictures of actual tops so I can figure how I want to orient and get the most out of the wood I have... hell I mock up the electronics. If I ever build a mocking bird I'm quite sure the universe will implode!!

going back to neck angle... on my cross section drawing... I auditioned angles from 3 to 5deg. assuming you are planing the body to the sm angle... you can pretty much choose an angle and raise/lower the neck until the string attop the fret meets the bridge at lowest height. Not trying to "tell" you anything (hehe, "as if" hope I don't come off like that) just pointing out that literally any angle constrained only by body thickness will work. It was kind of a revelation for me, as simple as it is... that this angle is really arbitrary if you are coming at it like that. admittedly it still kind of floors me... I'll shut up now.

When you have a German carve or any other carve that makes the pickup plane higher than the body rim where the neck meets the body, you're going to need much more neck angle.

My post was strictly about flat-topped guitars.

Now I'll shut up.

 

[mistermikev]

I've never bothered with the dual action truss rod that SM sells but I've used their single action kits several times, and they're just fine. Keep in mind, SM doesn't MAKE anything. They have vendors that make all their items and SM just resells them.

thanks sir... right I get the impression their dual action rods are simply the common blue chinese rods that have red shrinkwrap instead. not bagging on sm... some of their stuff is quite good, just as default behavior tend to not trust them unless I hear someone say "it's good", which you have, so thank you for that!!