#1 resource for Cigar Box Guitars, Free Plans, How-To, Parts & More!

Working on a new neck design - thoughts?

Hi all,

I've been thinking recently about the design I use for my necks, which is currently neck-though, with a recess carved out. As I use homemade boxes with thin lids, I need to accommodate bracing on the underside of the soundboard, throw pickups in the mix and I have a serious weak point. One of my 4 stringers has developed a bow, and I believe it is coming from the recess.

This is the recess cut out for a 3 stringer with a homemade box - this one is still solid but you get the idea of how much material I need to remove to allow for the fretboard standing proud of the soundboard, and also the bracing underneath.

The neck wood I have most easily available is oak, in lengths of roughly 1 metre, here is a proposed design in which the neck is cut and re-glued into supports.

[Apologies it's so poorly rendered - 5 minutes in Paint!]

The overlap forming the heel would be maximum about 150mm/6", the blocks underneath would be the same width as the neck, glued to the box and screwed from underneath to the neck - do you think this would be strong enough for a 3 or 4 stringer? (I haven't ventured into truss rods yet, nor do I have a router.) I feel that this needs to be the direction I move in so I can start messing about with resonators etc. without compromising the strength of the neck.

Your thoughts as always would be greatly appreciated.

Rick

2 members like this

▶ Reply to This

Replies to This Discussion

Permalink Reply by Richey Kay on January 24, 2014 at 2:13am

Good points, but this guitar is 25" scale, so hardly overlong. It's also only about a month old... I should have mentioned that the neck in the photo hasn't had these problems - the 4 stringer in question used the same design. Not sure I follow about cutting down thickness of neck outside the box? It's carved but the same thickness. Fretboard is glued on.

▶ Reply

Permalink Reply by Yankee Dog on January 24, 2014 at 7:21am

Where is the bowing occuring--

continuously and evenly

at the junction of the box and neck

inside the box.

Are there any defects in the neck wood?

▶ Reply

Permalink Reply by Michael Fred Johnson on January 24, 2014 at 5:37am

Hi Richey

Here is a drawing of a recently finished reso the neck is dove tailed into a hardwood neck block.Also a photo of the finished guitar

▶ Reply

Permalink Reply by Richey Kay on January 24, 2014 at 6:26am

Is there not a trust rod in this neck Michael? To be honest I think a good dovetail is beyond my ability, at least at the moment!

▶ Reply

Permalink Reply by darryl kernaghan on January 25, 2014 at 12:19am

just my opinion richey,but agree with cb john,the more overlap you can include without affecting playability,the better tensile resistance you,ll get,taken to extremes it might even be able to go thru under your planned reso cone

▶ Reply

Permalink Reply by Michael Fred Johnson on January 25, 2014 at 12:47am

There is no truss rod in that neck Richey,I've never used one on a 3 or 4 stringer.If you don't fancy a dovetail an alternative is to cut a slot the thickness of the box either side of the neck and just slot it in.This photo will give you the idea.Thanks for your comments on No's34 &35

▶ Reply

Permalink Reply by Richey Kay on January 25, 2014 at 7:29pm

That looks a bit more do-able. Thanks Michael!

Thanks for all of the feedback guys - I'll be using a few of these tips in my next build.

▶ Reply

Permalink Reply by robert jones on January 26, 2014 at 7:02am

Properly glued that joint will be fine and depth-wise the resulting neck will accommodate pretty much any standard pickup. You show more overlap at the join than I use and I've not had any significant bowing in the neck or failures at the join.

You are using an excessive amount of blocking. A small block on each end of the box to provide proper height indexing and a 2" screw through the side of the tail end of the box into end of the neck piece is more than sufficient.

I've built using both tailpiece and pinned bridges without any noticeable difference in the effect of string tension on the necks.

▶ Reply

Permalink Reply by 14 buck bass (aka antonio) on March 22, 2014 at 4:20am

ok mate , looking at your drawing just eliminate the little blocks and run your neck in a bit more and heel out a bit more stronger joint and stiffer neck. but i think thats what the chicken John vid is all about . anyway thats what i do with mine. when i glue up i make my heels as thick as I can and shape em down as i go . in any type of building engineering wise anytime you see a + in a diagram its usally a weak point. on the couple ive made where the necks got a bit thin in the rear ends ive made a suppliment side plate that i glueinto the box bottom on both sides .tight tolerance to the neck through. then when you glue up they take on a role as girders. this design works for train trestles so im sure it could hold 4 strings worth of tension. good luck with your experimenting mate. just for giggles I also very carefully poke my nose deep into the direction i want my neck to go as it ages. if it were on its own. then i take that bow and point it away from the top of the box. and construct hte neck that way. so it wants to not bow up toward the top of the box. one other hting to consider is grain pattern too.

▶ Reply

Permalink Reply by Ron "Oily" Sprague on March 22, 2014 at 4:35am

Richey,

Another way to deal with neck bow is with a tensioning system. No, not a truss rod; just attach an old E string from a medium bronze set to the heel with an eyelet screw, and another in the back of the headstock. Crank it tight to the neck, and your bow will be removed. You could even gouge out a small channel in the back of the neck to lay the string in, or get fancy and put an extra tuner on to tighten it up when necessary.

▶ Reply

Permalink Reply by 14 buck bass (aka antonio) on March 22, 2014 at 5:48am

Richey, what is the purpose of the blocks on the underside of the neck through the box , just my curiosity

▶ Reply

Permalink Reply by Richey Kay on March 22, 2014 at 7:29am

Cool suggestion Oily. Although since using this new design I've had no problems at all. the neck in question just need securing better to the box...
Antonio - those blocks are there to hold the neck at the right height and angle, and I screw the neck to the blocks through the box from underneath. I only use two, one at each end. I'll post a pic later so you can see mate.