How to ensure neck is 'squared' to box

I am building my 1st CBG. Everyone has been very helpful answering my 'dumb questions' and I thank you all for it.

I am about to the point of attaching (gluing) the neck to the box. It dawned on me this is a very critical step. Do it wrong and I could end up with an unplayable CBG.

1) If the 'front to back' angle is wrong (angle of neck to top surface of box) I could end up with an overly high action or conversely (and worse), fret buzz on the 20th fret even when open. How do I ensure the neck is parallel to the box face? Do I even want it perfectly parallel? FYI, my fretboard extends about 1/4" above the box surface

2) If the 'top to bottom' angle (90 deg angle of neck to box side) is off then the strings won't run parallel to the neck and intonation might be impossible (?). How do I ensure the neck is perfectly perpendicular to the box side?

I 'assume' minor adjustments can be made for 1 via the bridge height and for 2 via the tailpiece. I'd prefer those 'compromises' be minimal.

I've watched videos how to build a CBG and it seems like the builder just slaps the neck in and that's that. Am I being too cautious approaching this step?

Any tips/advice would be greatly appreciated.

the great thing about CBG's is you don't have to get them perfect every time - do your best but the most important thing is to leave a piece of yourself in it (not your finger...!) and as long as your heart and soul is in each build you'll have a unique instrument whether you make one or one hundred...they're your babies ...if you do that all your guitars will be perfect for you, and with a little luck others too! ;-)

btw to answer your question a set square will get it pretty well right before you do the glue...and i never found the need to make a heel for light 3 or 4 stringers, glue a length of wood between the underside of the neck inside the box, the secret is light but rigid, improves tone and sustain...

Slowpaw Cigar Box Guitars - nearly all straight, all built with lurrve...;-)

Replies

Joe Caruso June 11, 2015 at 8:00pm

Hope this diagram helps explain one option. Here's how I have my neck go through the box, with a brace at each end, which is screwed into the cigar box. Everything within the box is centred, then the neck is centred. I recess the top of the neck within the box so the lid closes snugly (table saw); and a bit of a recess where the piezo pickup will be attached to the cigar box lid. I define the action by working with the height of the saddle and the nut. Brass corners keep the lid down. Now, with the one guitar I built that had a mag pickup that stuck up high above the top surface of the lid, well yes I did have to make some additional compensations to have playable action. I ended up elevating the fingerboard beyond where I had planned - and its stll playable - I have yet to build one where *something* didn't come out as planned because every one has been a little different but live and learn ;-)
Skeesix June 11, 2015 at 7:26pm

As far as centering the neck, I mark the center line of the neck and the center line of the box with a pencil. Then just match them up.

As far as the neck angle, I attach the neck with screws, then you can hold a yardstick or long straight edge along the neck to the bridge simulating the strings. This will also give you an idea how tall to make the bridge.

If the neck is not glued, you can make adjustments with cutting the notch that makes the angle deeper or adding shims if you cut too much.

You actually don't want the neck parallel to the box face - it should have a slight angle which will allow for better playing action.
Slowpaw Steve T June 11, 2015 at 10:21am

the great thing about CBG's is you don't have to get them perfect every time - do your best but the most important thing is to leave a piece of yourself in it (not your finger...!) and as long as your heart and soul is in each build you'll have a unique instrument whether you make one or one hundred...they're your babies ...if you do that all your guitars will be perfect for you, and with a little luck others too! ;-)

btw to answer your question a set square will get it pretty well right before you do the glue...and i never found the need to make a heel for light 3 or 4 stringers, glue a length of wood between the underside of the neck inside the box, the secret is light but rigid, improves tone and sustain...

Slowpaw Cigar Box Guitars - nearly all straight, all built with lurrve...;-)
Westsailor . June 10, 2015 at 7:24pm

Finally, my solution to the pickup slot being too deep in the neck problem
- Richey Kay > Westsailor . June 11, 2015 at 1:05am
  
  Excellent looking build there Westsailor. If I had one critique it would be that there is a weak point where the neck meets the box. On a future build you could potentially extend the stick running through the box and use it as a heel glued to the underside of the neck, extending out to roughly the 16th fret or something.. It might be worth screwing the neck to the box with an angle bracket just to be on the safe side.
  - Westsailor . > Richey Kay June 11, 2015 at 9:08am
    
    Point taken. I've learned a lot during this build. My next build ( a fretless 3 string) will extend the stick enough to allow a heel.
    
    I'm curious though... what would be the difference in this build and (most of) the others I've seen where the neck runs through the box and do not have heels?
    - Richey Kay > Westsailor . June 11, 2015 at 10:39am
      
      Well, you have a combination of a very deep box lid, and of course your cut out for the pickup... You're left with about 1/2" of neck thickness where it meets the box. I'm sure you'll be fine though :-)
- Thumper > Westsailor . June 10, 2015 at 8:20pm
  
  Excellent "f-hole" cutouts !!!!!
  - Westsailor . > Thumper June 10, 2015 at 8:58pm
    
    Thanks... I was afraid I was gonna screw em up and be left with a nice CBG with messed up f-holes. Just takes patience, a sharp carving knife and a Dremel. And oh yea.. more patience :)
Westsailor . June 10, 2015 at 7:22pm

Another view

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