Is a cutaway neckblock asymetric?

[HungryWookie]

Hi Gang!
So I've built about 10 guitars, but mostly electric. My only acoustic was a Stew-Mac kit. And tho that was many guitars ago, I gotta say that was probably more challenging than all of my from-scratch electrics.

Though it is back-asswards, without any formal training, my method of improving my guitar building skills has been to just start making something I want, and then tackle problems along the way. I feel that forces me to understand exactly why things are built the way the are as well as seeing my options without following a standard template. It's slower and comes with mistakes, but one day I'll be better for it.

Anyway, I'm winging an acoustic Venetian cutaway classical guitar. I made a neckblock and rough-cut a neck, and realize that to fit the cutaway, I need to shrink my neckblock. I've seen a few examples on both sides, but is the typical cutaway neckblock asymmetric with the mortise favoing the cutaway side? Or do people just trim the neckblock to have it be symmetric and match the exact width of the neck at the join?

Any advice is welcome!
Thanks,
-Sully

[Shuksan]

For a standard type cutaway design, the neck block is typically asymmetric. The width of the block is reduced on the cutaway side.

If you want the cutaway side to end up flush with the edge of the fretboard, you need to remember to allow for the thickness of the cutaway side that is glued to the side of the neck block. In other words the neck block width needs to be reduced to less than the width of the fretboard at the neck/body joint by the amount of the side thickness in the cutaway.

For example, say the fretboard at the neck/body joint is 2" wide. The mortise in the neck block is centered on the centerline of the fretboard. The width of the fretboard from the centerline to the treble side edge (cutaway side) is 1". If you want the guitar side in the cutaway to end flush with the fretboard edge at the neck/body joint, the neck block needs to be a little less than 1" wide from the centerline on the cutaway side. "A little less" = the thickness of the side at the end of the cutaway. So if the side is 0.075" thick, the cutaway side of the neck block will be
1" - 0.075 = 0.925" wide measured from the centerline at the neck/body joint. Hope that makes sense.

Here's an example of one I made for a guitar with a Venetian cutaway:

[IMG][/IMG]

[HungryWookie]

Thanks, Shuksan!
That's exactly what I needed. And as things were coming together, I could tell that I would want my fretboard to cover the width of the side at the "corner" join where the cutaway meets the other side.

If one were to make the neckblock symmetric around the join, it basically would only cover the width of the guitar neck at the join. Would the worry then be that there wouldn't be enough support? If you have it available, what is the width of that block you pictured?

Thanks!
-Sully

[Shuksan]

That neck block was 2 1/2" wide.

I wouldn't want to reduce the neck block width to be the same width as the fretboard. I would be concerned about loss of strength. I haven't tried it though so I can't say for sure.

One other thing. You may have already noticed this, but there is a butt joint where the end of the cutaway side meets the end of the bass side which extends across the end of the neck block. It's best to butt the end of the bass side to the back of the cutaway side at that joint. That way if you don't put binding on that joint or don't use a wide heel that would cover the joint, the joint won't be visible when viewed from the side:

[IMG][/IMG]

[HungryWookie]

Thanks for the pic and the sizing! Yes, I was thinking thru that join and realized I'd want to hide that joint. Appreciate you answering my questions, and the pictures really clarified everything. Happy Building!
-Sully