Another non uke luthier question

Hi, every other question I've had, you all have helped immensely! I was building a kora, however the neck warped badly so I'm trying again. Trying to build this zither version of a kora now...
http://dennishavlena.com/harp-kora-2.htm

I have the frame hollowed out, I've looked everywhere for 1/8" plywood, today I'm going to drive to the nearest larger city to a craft wood shop for it. The guitar tuners are on their way...

There are three things I can't quite figure out with this thing, and I was wondering if anyone had any thoughts? The rails that the tuners are attached to, I can't figure out how wide they should be, nor how much overlap they should have with the frame. And finally whether the plywood lining th inside of the gear channel is continuous with the soundboard? Any thoughts are greatly appreciated!

Here it is being played:
https://m.youtube.com/watch?v=nEaYFD2qp7s

The link you gave has email contact details at the very bottom.

dhavlena@gmail.com

Why not email the guy that made it? Bob

I have emailed several times, he has not responded.

The other alternative would be to find a 2 x 10 that's near quarter sawn and relatively clear grain and slice off a couple of 1/8 inch slices and use them for the soundboard and back.
Plywood will likely be more stable with changes in humidity, but a solid wood top might give better tone.
Another possibility would see if you can find lauan door skins locally. These are usually a three ply plywood the size of an entry door rather than a 4 x 8 sheet, and they're about an 1/8 of an inch thick.

Here is a link to some mahogany and poplar Plywood (1/8" thick) : http://aircraftproducts.wicksaircraft.com/item/aircraft-plywood/ogany-and-poplar-plywood-aircraft-grade-mil-p-6070/1-8x2x4m90
They sell other thicknesses and sizes as well.

I have used this for cajons in the past and they sound great...have not used for stringed instruments as I use solid wood for those. What I can say is that it is nice plywood and the best I could find. Would love to know if you find anything better.

P.S. I love the kora and had never seen anything other than the traditional gourd and skin. Interesting idea.... it definitely sounds a lot different to my ears but still nice in its own way.

I just had a look at the build site and given the rails are referred to as scrap hardwood and Denis's propensity to build anything out anything I would not stress it too much. By eye they look around 1/2 by 3/4 inch.
Similar in concept to the Paraguayan harp I would class it as a double sided zither because the soundboard is parallell to the strings. I wouldn't bother hacking up a 2by12 a triangular frame knocked up from 2by1 with joins in the corners would be fine given the joins will be braced by the plywood.

Jardin, I agree it is not a perfect match for the Kora, but it can be tuned the same and played with a similar technique. So I can try it out for a while before paying a jillion dollars for an authentic instrument.

Titxh (and all) out of curiosity, could I just use a hardshell piece of luggage as the cabinet for this? Or I guess it's called a sound box?

Titche, that's my dream but I'm not confident in my ability to figure it out. How would I do the neck do you think?

Actually Dennis's site has a few koras on it. Just put your suitcase where the gourd goes and you should be cooking with gas. I have only seen two koras live in action. One traditional gut and knot tuned played by an irishman who was continually trying to tune it and the other by an african guy with geared tuning pegs where it stayed in tune. I have never even tried making one.

http://dennishavlena.com/mackora.htm

Look also at as many on the cigarbox nation site as you can find and youtube vids of people playing them.

Post questions on cigarboxnation.com as things are a little weirder over there with people making everything from amps to zithers and all letters imbetween. Strictly speaking this site is supposed to be for ukes.

Dennis also had a handmade music clubhouse forum but I can't see too much happening over there.

Alright, I built a neck last night, many thanks for all the advice! Will post a pic when done.