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Hi all, never built a guitar before. I'm tall, and have disproportionately long arms. So much so, that a Les Paul is really uncomfortable to play when sitting down. The angles get awkward when trying to play further up the neck.

Recently bought an SG, and it is much better. I'm thinking something like a Firebird would be even better. However, I don't need any more six string electrics, and would really like to have a 12 string. 12 string Reverse Firebirds and SG's aren't really obtainable, so I think it would be enjoyable to build my own.

Building my own, and using a "neck through" design would make it it simple to come up with a body shape most comfortable to me. I've got large 3D printers, and a CNC router table. If I had a neck through neck, I could easily 3d print, or CNC cut out various shaped bolt on "wings". That would let me come up with and test my own shapes. Then I'd have the most comfortable guitar for my frame, and I could also make the body look however I want. I also think the neck through design would be very well suited to the additional forces created by the 12 strings.

I've done a bunch of searching online, and 12 string neck through kits don't seem to exist. Anyone know of one? Or have recommendations for a company that might be able to build one for me? A Pre-built neck would save me a lot of time and trouble for a first build.

Maybe finding a wider necked 6 string version, and adding wood to the headstock to accommodate the extra tuners? I may need to do more research to figure out how thick the neck really needs to be for a 12 string electric.

Any advice or pointers would be great. Thanks!

^^^ THIS. ^^^

Keep at it, and then come back.
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Sounds like a fun project.


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Local, you really need to do a lot more research. Start with Melvyn Hiscock's book on making electric guitars - the third edition has just been released but the second will do. Specifically he builds a thru neck bass guitar and you will learn a lot from that chapter (as well as the rest of the book). One thing to look out for on a thru neck is that there is usually no overstand on the neck over the body so the proper geometry is obtained by putting a bit of an angle into the neck. That is moderately easy on a set neck guitar but can be a real nightmare on a thru neck.

Nest is to get out and play as many 12 strings as you can. I know there aren't many, there is probably a good reason for that LOL. I play 12 string (mostly acoustics) and have built a few. There are just lots and lots of considerations before you dive into this. Here is one of my creations just to give you an idea



If you simply want an electric 12 string the easiest way would be to buy a 12 string neck from Warmoth and buy or build your own tele style body to bolt it two. Precision might put together a kit for you if you give them a call

https://precisionguitarkits.com/

I'm pretty sure the BC Rich double necks were thru neck, I don't know if they offer a single 12 string version.

Now do your research.

Thanks for the replies guys!



That's some of the research I was hoping to avoid, may be no getting around it, as I still can't seem to find a 12 string neck through neck. I'll see if I can find a copy of the book you mention. I am time limited, if after some research I discover that things are going to be more complex, I may need to take more drastic measures. Like finding a 12 string that plays well, and wouldn't be a blasphemy to stick onto a table saw.




That thing is Awesome!

Unfortunately I live in the middle of nowhere. Over the past few weeks I've done a bunch of driving to towns big enough to have a guitar shop to see what I could find. The electric 12 string options were basically non-existent. I own a couple acoustic 12 strings, one of which is my current favorite guitar (Tacoma DM-912). So I know what width I'd like the neck to be. I'm hoping the thickness could be cut down some for an electric with lighter strings.



I will keep looking, especially at the options you mention. Could find a regular 12 string kit of some sort. Wouldn't be through neck, but it would at least be something I could customize to fit me more comfortably. I'd really like to do a through neck though, as I'm led to believe they have better sustain, which would be great for cleaner amp settings. It also seems to make sense that tuning stability could be better. I dunno, maybe those advantages aren't actually that big.

If only Gibson made these on a regular basis.

http://legacy.gibson.com/Products/Elect ... mited.aspx

There are no shortcuts to making a guitar like that. Do the research, read the book, build the guitar from scratch. It is worth it, trust me.

Here is how the double neck was built. Just ignore the six string neck

https://www.tdpri.com/threads/double-trouble.1003555/

Its actually based on the infamous Gibson EDS-1275



When I decide to build a guitar I have a whole list of questions that I ask myself, pretty much in this order
- what exactly am I trying to build
- how will I string it and tune it (very important for a 12 string).
- what scale will I use ((combined with the last question this determines some tension issues)
- what kind of geometry do I want (angled neck, overstand, flat top, arched top......)
- how many frets clear of the body (where is the neck joint)
- nut width, bridge spacing, string offset, string spacing...
- body style (solid, chambered, semi hollow, hollow....)
- neck joint (screwed on, bolted on, glued on, dovetail, M&T, thru body)
- wood and finish and all of those things
- pickups and electronics

I have learned one fundimental rule a long time ago - build to fit an available case if possible (custom cases are expensive)

There is a good reason for Gibson to use a thru neck on the SG - they have notoriously short tenons that fail, even on 6 strings. Ask yourself realistically if you need 18 frets clear on a 12 string (do you play your Taylor at the 18th fret?).

Your research should definitely include looking at the various electric 12 string currently on the market. Fender has a couple, Rickenbacker of course (with their bass ackward stringing and funky head stock), Taylor has a 12 string version of the T5 as I recall. There are some PacRim guitars by Regal and the likes - look them over carefully. The BC Rich is a thru body - that might give you some ideas.

Good luck, have fun. I hope you find what you are looking for.

I've got a paperback of the aforementioned book ordered from ebay. While I wait for it to arrive, I'll have to see if I can actually lay hands onto an electric 12 string and take some measurements.



Yeah, unfortunately what I want is further out there than I was thinking. Guess it's just a lot cheaper to build things with a separate neck. It seems like more work though if CNC operations are possible, and you don't care about machine time. If I have to let my CNC machine run a few days to cut out a guitar neck, no big deal. To expensive for mass production, but for a one off it's all hands on time saved.



Good thread thanks, I will have to read through the whole thing.




Very good list. I have ideas for most of those, though some will require info that I'm hoping is contained in Melvyn's book.

What: 12 String Firebird-ish. Gibson actually made some of these in the 1960's, but with the alternate bodystyle.

String and Tune: I would like to use the banjo tuners that the original firebirds had. Think they give a cool look. Hopefully Melvyn's book goes over what kind of angles from the nut to the tuners are acceptable. I can quickly and easily draw up the entire guitar in CAD, so figuring all of that out won't be a problem. Just move things around until everything fits, and I get optimal angles within my aesthetic choices.

Scale: I think going between Fender and Gibson standard lengths isn't a bad option. A bit less tension than Gibson, and perhaps not so loose as Fender.

Geometry: Gonna need to reference the book or other sources for this one. Obviously the body, will basically just be a shaped slab of wood. Once I know what an optimal neck angle is, that can easily be taken care of with my CNC. Machine time could be high, but that doesn't matter.

Frets: I often play above the 12th fret on my acoustics, though 15 is kind of the limit without a cutout. Since I've already decided this will be neck through, I can do like the standard firebirds, and have pretty much all the frets exposed. Probably do a standard 22 fret guitar.

String Widths: For the nut, string spacing/offset, I plan to just copy my Tacoma 12 string. I've tried several different widths, and 1 3/4 is just right. Any narrower, and my thick fingertips run into interference issues. Could play around a bit with spacing easily enough. I can simply 3D print a bunch of custom nuts on my resin printer to test things out. Once I find one I really like, I can send out the 3D model to be made relatively cheaply out of a more suitable material. Or CNC cut my own. I have a lot of tiny PCB cutting bits that would do the job.

Wood/Finish: Gonna need to do some research on the wood. I just want something durable, and stable. I think I will probably paint the entire guitar. The car vibes you get from a Firebird-ish body shape is kinda made for car paints.

Electronics: I'm thinking Firebird pickups. They're kind of their own thing. I'll need to do some research and see if the 12 string Firebirds from the 60's were any different in size or shape.



Good point. Though I wonder at how hard a custom case would be. CNC route out a bottom and lid shape from some plywood. Route channels into those shapes so I can just slot in flexible plywood sides. Maybe add some fillets, then just truck bed line the whole thing, inside and out. Would be stupidly fast to build, and very strong. Tons of colors to chose from too. Then all that's left is to pad the inside with whatever that fake fur stuff is. Maybe I should start out with a case for one of my Acoustic 6 strings that doesn't have a readily available market option.



I will definitely be checking out all the options. Might need to plan a trip to get someplace with more options where I can go hands on. Thanks for all the help!

Here is a piece of advice from an old woodworker. A CNC will not replace knowledge and skill in traditional wood working. It can enhance it but won't make up for a lack of it.

Old machinists will say the same thing.

Machines don't learn, they don't have intuition, they don't have experience.

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

And machines don't care if your finger(s) get in the way. they don't feel a thing
I know this

A few comments on your comments

- I've never seen a Gibson Firebird 12 string so I can't comment

- There are two styles of banjo tuners - friction, which are relatively inexpensive and don't work very well and geared which are expensive and do. You need twelve, remember, they are heavy. My 12 string builds used mini-Grovers to try to minimize the weight and head stock size. Lay out y our string paths

- Hiscock does not discuss the break angle at the nut, however you will find it discussed on this forum from time to time. Most heads are around 16 degree angle. You can calculate the down force at the nut if you know the string tension and break angle (its two times the sine of the angle). I'm not sure knowing that force will tell you much (it tells you a lot at the bridge)

- You have scale lengths reversed - shorter Gibson scale has less tension (it the square of the ratio). People frequently go to longer scales on twelve strings when they tune down - my ladder braced 12 is 26.5, strung with cables and tuned in the cellar.

- Unlike acoustic twelves which have about 150 percent of the tension of a sixer (depending on a bunch of things) the usual string 10 - 46 12 string set that many people use has almost exactly 2 times the tension of a six string with 10's on it. It still is a very manageable 210 pound or so, but should be considered when you design your guitar. Obviously there are all sorts of altered tunings.

- Melvin does spend a lot of time on geometry and I have written a little discussion at another forum

https://www.tdpri.com/threads/building- ... ty.991659/

Basically you want the fretboard plane to just touch the tops of the saddles at there very lowest adjustment, with most bridges that gives you good playable action and adequate adjustment. You get there with a combination of neck angle (remember zero is an angle) and overstand. Both of those can be adjusted depending on whether the top of your guitar is flat or arched and how tall your saddle is. This is one of the reasons a thru neck is potentially bad - you have to cut that angle and overstand into the neck and have no opportunity to adjust it as your build progresses.

- speaking of bridges, there are relatively few twelve string bridges commercially available. Your choice of bridge will determine fretboard radius and string spacing. Some bridges intonate better than others. Do your research and have your bridge in hand when you do your design

- most 12 strings intonate pretty terribly - you've got a big fat string right next to a skinny little octave string. It gets worse as you go up the neck. I almost never play above the 12th fret on any of my 12 strings, in fact the ladder braced one is only 12 frets clear. Trying to gain access to those upper frets means you will compromise your neck joint - one of the problems with SG style guitars.

- wood and finish is your choice, of course. Many of the traditional woods are traditional for a reason.

- can't help you with pickups. Your string spacing will be slightly wider than a sixer, but I used standard humbuckers on the double neck.

- as far as cases, the last custom cases I bought were over 300 dollars and very long delivery. They are beautiful and fit perfectly but cost more than some guitars. When I built the double neck I made sure that I had a case that would fit and made a few modification so the body to make sure. The longer head on yours will limit your options



I'm going to add one more thing. I come from a fabrication background where we used CAD/CAM/CNC for many of our parts. I know the amount of time and effort required to model a typical 3D assembly. If you are really good with parametric design you can use that to your advantage - stretch the scale length a half inch and see what happens. I also know how much work it is to make a one off assembly of parts (body, neck, fretboard, bridge, head..... no matter how good you are with your CAD and your mill. CNC is not a part of my guitar building but if it was there are only a few things I would have it make. There is a sub forum to OLF that talks about CNC - might be helpful.

Once again, good luck. I'm not trying to discourage you, just want you to know what you are facing.

Yeah, I'll have to do some research. Taking a set of calipers to a guitar store will hopefully give me a bunch of good info. I can measure various tuners, sketch them up in CAD, and try seeing how different options line up. Just gonna have to see how things look, I'll keep all options on the table. Heck, if necessary I could do half banjo, and half guitar style.



Oops. Didn't have that in my brain correctly, I may just stick with with the Gibson scale. It's quite likely that I'll be playing in D standard for a lot of things, and that'l already soften things up a good bit.



Good info. Since I'll have to build the neck myself, I might as well get as much advantage from my CNC machine as possible. Can make several test necks out of cheap wood. Wonder if pine would be suitable as a test. That would let me check angles in the real world.

I'd really like to cut a few different through neck samples with different neck profiles. I want this guitar mostly for fingerstyle, and being able to comfortably cover the base string with my thumb is a priority. There's just not enough 12 string neck varieties out there that I can reasonably get my hands on in the real world. I could test various 6 string guitar necks, but I think the added width of the 12 string will really mess with those comparisons.



More good points, having that kind of hardware on hand will be a good idea before starting on the CAD work.




Yeah, I'd imagine I'll probably be stuck needing a custom case. The head will be long, and the body will likely be long as well. All depends on which of the various body options I can try fit my frame best.



Yep, CAD and CAM time can be a bear, especially with complex parts. I'm quite fast with parametric design though, so the actual modeling part will be a breeze. CAM and actual CNC setup time for something this large will be a bit of a change. I built my CNC router mostly so that I could make RC aircraft parts, tiny and relatively quick. I overbuilt it, but haven't done a lot of larger parts machining. Will still be fun though. Getting more use out of my machine will be good.

And once you've gone to all that CNC setup work, if the guitar turns out well, cutting out more of them will be easy.

I will check out the subforum, can always use more info. Thanks again for the reply!

These 12 strings are pretty cool. Wrong size to fit me, but the bridge is neat. 6 strings go on the top, and the other six come up through the backside of the guitar. Gives enough room to have individual intonation adjustments for each string.

https://reverendguitars.com/guitars/airwave-12-string/

They're GOTOH brand bridges, not something I've heard of, but it looks like they're available for purchase. Gonna keep looking around, but I think buying a bridge and some of the other hardware needs to be the first step. Gotta have stuff in hand to draw it accurately in CAD.

Gotoh is respected hardware, the world over.

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

That's good to know, thanks. Did a bunch more searching, and I think it's probably the best bridge for what I want. Will probably order one here shortly.

Got the book in the mail. Gonna see if I can't read through the whole thing some evening this week.