I have found a couple sources for Cigar Boxes around my "summer home" in the SF Bay Area. I quickly made a one-stringer (diddly bow-like) CBG w/o frets, mainly to get the idea of how to attach the neck to the cigar box. Another goal was to make an instrument I could use to play around with a slider while using a chop stick to pound on the strings (a new style of playing), as well as picking while fretting with imaginary frets (also a new experience for me). Wish I knew more about how to play the Blues. My 5 y.o. daughter likes to fool around with this one- stringer as well, so I might just let her keep it as a toy. Anything to encourage her music interests. I can always add frets for her later.
Since all of the cigar boxes I've found are smaller than I imagined, I think they're probably best suited for use in a smaller instrument such as a ukulele. Fortunately, I'm familiar with ukes, and my favorite sized uke is the concert size (length = 24'' or 25'', a 15" scale with 17 or 18 frets, and 4 strings tuned GCEA). So I have been thinking about building a Cigar Box Ukulele (CBU). I'll use this Blog on CBN as my "thinking pad", and perhaps some of my ideas can be of use to other want-to-be Cigar Box luthiers (like me).
My first concern was how difficult it might be to reach the highest (pitched) frets (15, 16, 17 and 18) which are usually found on the part of the fretboard that overlays the body. With a somewhat bulky rectangular cigar box as a body, they might be hard to get to, so I decided I want to extend the neck a couple more inches so all the frets will be on the neck. To make sure this would work, I ran the Stew-Mac Fret Calculator to make sure I could get all the frets on a 10" neck. So, here's the fret positioning information for a 15" scale length ukulele:
As you can see, with a 15" scale length, you can have a 18 fret "fretboard" on the neck of 10" and have
5 more inches of space across the face of your cigar box before you reach the bridge.
Let's see. The cigar box I want to use is 7.75" wide x 8.0625" high x 2.75" deep. I want the bridge placed about 1/3 of the way across the cigar box from the tail piece. That's 2.58" across to the bridge, leaving 5.17" of space before the neck, where you'd strum with your right hand. But, the bridge will have to go (2.58 + 0.17 = ) 2.75" up from the tail piece to maintain the 15" scale length, with 5" on the box and 10" on the neck. Compare that to my 20 fret concert uke which has just under 4.75" of space between the last fret and the bridge. That's not bad. I never use those higher frets (19 & 20) anyways.
Time for another diagram.
By the way, this is not a left handed uke. I draw them as I hold them, not as the audience may see them. But, if you want a left handed CBU, all you need to do is to reverse the order of the strings. Everything else is symmetrical around the central axis running down the middle of the instrument, so it's good for right- or left-handed players.
The ruler above the neck shows the 15'' scale length, with 10" over the neck for the frets, and 5" over the box for picking and strumming. The nut and bridge will be a movable bridge (at least initially) so I can (hopefully) correct for any intonation problems, at least those related to nut and bridge height and placement. An instrument with "good intonation" is in tune throughout its entire scale, and that means my fret placement has to be exact, as well as good nut and bridge placement. Also, sometimes tilting the bridge counter-clockwise a millimeter or two can help with intonation problems caused by thicker middle and bass strings (but maybe not for the re-entrantly tuned 4th string - another problem to be solved later). So, it's probably a good thing to keep the bridge and nuts movable until you've completed your instrument build and have played with it a while and have had a chance to tinker with its setup to your satisfaction.
The ruler at the bottom of the diagram shows the length-over-all of the instrument, which should be (ideally) 24''. Mine is a bit short, I believe because of the short size of the cigar box resonator. Notice that the stick (neck) of my uke will run through the cigar box and come out the other end, by about 1". There I will either use some kind of bracket for a tail piece or drill 4 holes in the tail end of the stick and anchor the strings on this side using beads or something. I'll figure out those details later. I prefer this method of mounting the stick (neck) through the box because the stick (neck) will hold all the stress from the strings once they are tuned. That means I won't have to set up any internal bracing or figure out how to do any special neck-to-box joints. Keep it simple, Sam.
Notice I use two sound holes on either side of the four uke strings. This is pretty "un-uke-like", because most ukes have a larger single sound hole placed strategically under the strings like any acoustical guitar. However, this change is dictated by the fact that my uke will have a stick (neck) running down the middle of the box where a single sound hole would normally be placed. A stick covering most of the sound hole would make the sound hole pretty ineffective.
The Headstock
I usually begin at the head and work my way down. As the diagram above shows, the four strings will be run from the tuners on the headstock, across the nut, down the neck and across the cigar box to the bridge and are finally terminated at the tail piece. The strings are drawn 3/8'' apart, which is pretty standard for ukuleles and stick dulcimers. If you prefer 1/2" apart, you can do it with a wider stick (neck). The separation between the two outer strings and their respective edges of the neck is 3/16''. So, with 3/8'' string-to-string spacing, the width of the neck should be very close to 1.5''. For 1/2'' sting-to-string spacing, the width of the neck should be close to 2", providing a 1/4'' separation on each side from the two outer strings and their respective edges of the neck.
However, on a typical ukulele, the neck usually has a taper of about a centimeter on both sides, getting wider as it approaches the body. But, for simplicity's sake, I am NOT going to cut the neck with a taper. This decision is based on the fact that I am working with hand tools (no table saws, etc.) and because my wood working skills are rather limited. For these same reasons, the back of the neck will have minimal rounding and there will be no heel on the neck as used on traditional ukuleles to connect the neck to the sound box.
As you can see, the headstock design will be rather plain and simple. Like your typical ukulele or guitar, the head will be tilted "downward" by about 15 degrees. This usually involves cutting the head-piece off the neck at a 15 degree angle, flipping the head over and gluing it back on to the neck. I'm told that this is called a "scarf joint" and that the shallower the angle, the stronger the joint. So, a 15 degree angle will be stronger than say a 45 degree angle because there is a larger surface area for the glue to hold the two parts together. You can also use wood dowels or screws for additional strength, but my experience (so far) indicates that they aren't really necessary if you are using a good wood glue, are clamping the pieces together and letting it dry overnight.
My headstock will be 5'' long, 2'' wide, and 7/16" deep. Yes, I know the diagram says 0.75'' (3/4"), but I forgot to take into account the requirement of the tuners that the headstock be 7/16'' deep. Your tuners may differ, so double check that measurement with your tuners. I'll have to figure out how to plane down the head to 7/16". Lot's of planing, filing and sanding, I guess.
The headstock build will also involve gluing two "wings" or side pieces on to widen the headstock to at least 2 inches. The 4 separate tuners will be placed in a "2 by 2" configuration with about two inches separation so there will be plenty of room to route the strings to their respective tuners. Hmmm... Since I have to add to the width of the head, and plane it down by 1/4''; maybe I should go back to the hardware store to buy a piece of wood that is already 5'' x 2'' x 7/16'' (more likely 1/2'' deep), and preferably in the same kind of wood. That would simplify the job a lot.
Also, in the diagram above, I have added maybe 1/4'' to the length of the neck between the nut and the headstock for a 'slop factor", as my hand-sawn cuts aren't usually as accurate as I would hope.
I'll be focusing more on the headstock on my next post.
- Rand.
