I want to build a Can Jo for a child, what would the best scale length be? I am thinking of around 15-18 inches.
Sorry, others are likely better at a direct reply to your q, but myself being 5' 8" and fairly short arms, I can say from plenty of experience that a total of 18 and even 16 inches is not only good for short peeps... but for adults who want a more forgiving slide guitar. You get to the notes quicker and I find an 18 in. scale great for 2 octaves depending on where the neck joins the body, neck on top or within and such. -Glenn
I've built 10 Canjo's and 10 Spamjo's for sale at a craft fair and I've used a standard 25'' scale with diatonic fretting.I think they look a little too childlike on a much shorter scale and I'm sure they won't have any trouble with that length of neck.With a longer scale,you can include more frets,too (mine have 10 burnt in frets).As with every build on here,it's what you feel is right for you....
Just take the scale from a soprano ukulele which is what you're looking for in size and give that a try. Also you can take the same diatonic scale from a dulcimer and shorten it.
There's an issue with the strings on small-sized instruments. I hadn't thought of this until a buddy of mine tried to string up a 2/3 (16.5") scale 6-string guitar for a kid at our church.
The strings are shorter, therefore they don't have to be nearly as tightly stretched to reach the standard pitch. Problem is, the strings are too slack and tend to be buzzy on the fretboard. Seems like the only solution would be to use the heaviest strings available so there would be as much string tension as possible. (Setting the action higher seems like a mean trick on a young beginner.)
I have no experience with nylon (or "gut") strings, but I wonder if they would buzz less and be easier on a kid's finger. Of course, on a 1-string canjo the metal edge of the can may eat through the nylon string.
Ideas greatly appreciated... I, too, have considered making "children's" 1-string instruments as teaching tools.
Regarding the edge of the can eating the nylon string,i had some issues with the string buzzing in the pop rivet I used as a retainer for the string.I took the rivet out, which left a hole of aprox 4mm,threaded the string through a shirt button,threaded the string through the middle of the hole with the shirt button as the retainer and because the string now didn't have the rivet to vibrate against,the buzzing disappeared.Also the string was in no danger of rubbing against the metal edge of the can as it now sat in the middle of the hole.
This method assumes,of course,that your string ends at the base of the can and doesn't continue on to the bottom of the neck where there would be an angle of the string.
Nylon strings would certainly be a little easier on little fingers but I don't think they sound as good and as loud and a light gauge high E or B string is very light,too...
I have made a single string, 22 inch dulcimer fretted canjo,the question is what string should I use , and what tuning?
Most people,including me,use a light gauge high E or B string.The tuning doesn't really matter as it's only 1 string so just tune it until it sounds right.....
I don't think my rant about short strings being too slack applies until you get smaller than 22". Any guitar, canjo, etc. with a sounding length in the range of 22 to 26 inches can probably use "regular" guitar strings and tune them to the notes that the manufacturer specifies for them. (i.e. For a G, buy a G string, etc.)
Have a look at Ben's (CBGitty) knowledgebase at CigarBoxGuitar.com where he's been suggesting string sizes for different pitches and providing recordings of what they sound like. (He'll also sell you the strings you need--which can save you money.)
Personally, I recommend that you tune to either high or low D. That way, with "diatonic" frets you can play easily in D major, G major, and E minor--all favorite keys for guitarists. Tuning to D is consistent with what most of the Appalachian Dulcimer books recommend for dulcimer, so you can get a lot of tabs from dulcimer guys. (However, if you plan to jam with fiddle and mandolin players a lot, you may want to tune to an E instead, so you can play in E major and A major--which fiddle guys seem to prefer.)
Good luck. Post a recording when you get it strung...
Thanks all for you help, very useful