Amazing how some things that should be obvious are easily overlooked until they punch you in the nose.
I just finished my 2nd CBG; a fretted electric with piezo pickup. Thought it'd be cool to have the strings come up through the cover of the box a couple of inches behind the bridge. Worked great until I tightened the strings up. The tension on the strings tends to pull the box cover towards the head of the guitar. Tried temporarily clamping the cover on the sides, just to keep it from moving, but then it is actually separating the top panel of the cover from the sides.
You can kind of see what I am talking about in this picture.
I was thinking maybe just glue the box shut. But that won't work; I need to open it to change the strings!
Thinking I may just have to mount a tailpiece of some sort.
I guess I could say, "Thank you for making that mistake, so I won't have to."
You're quite welcome. That's exactly why I posted this.
That was a thought. You can see a couple of holes I drilled in the cover, but I didn't think of the blocks in the bottom to screw in to. Might have to revisit that. Need to find some sort of tarnished pewter or brass looking screws.
Sounds like you're on the right track. This is something I do with all of my cigar box builds, even though I generally don't run the strings through the body. If the box lid is nice and sturdy, you shouldn't get any rattles or undesirable vibrations, and you will get improved volume and tone. Good luck, and nice build by the way :-)
Since I've got the neck running through the body, I decided to just try to put a screw in at the tail end and another right behind the neck, seems to be doing the trick. They are brass screws, I'll have to find a way to tarnish them a bit to look more like the rest of the guitar.
The neck actually rises about 3/16" higher than the top of the box. It ends at the side of the box and is attached to another piece of wood that comes out about 2.5" towards the head and inside the length of the box along the bottom.