For tuning pegs it uses bolts (2 ¼” long by ¼” diameter, fine thread) that have a hole drilled for the string to attach. At the
other end of the strings is a 1 ½” nail, which is pounded in at an angle, and then the head is cut off and filed smooth. The nut
and bridge are made of acrylic (like Plexiglas or Lucite), sanded smooth on the edges and then notches are filed to hold the
string spacing. They are held in place by the string pressure on them. The scale is a little shorter than a guitar, so that it can
use used guitar strings: you just cut off the messed up tuning peg end and there will be plenty of string left to fit nicely. If
you have a lot of instruments to make, you might convince your local music store to donate some strings. The gauge is not
I made my scale from a steel guitar, where the second fret had the correct distance to the bridge for the nut of the dobro. I
copied the distances, and my pdf version should print out correctly. Make sure when you print it that it is set for 100%.
Some kids drew the scale directly on their dobro, but some also had difficulty with the accuracy of the lines, and didn’t
understand the need for a little accuracy. If the frets are too far off, it will be difficult to make decent sounding music. For
many kids, a project like this is the first time ever that they will use a hammer and nail, a square, sandpaper, or a wrench.
Of course you can use a tuna fish can, but the name “Tuna Can Dobro” just doesn’t sound as good. Also, they are usually
made of steel, and steel cans sound terrible. They just can't give the tone of aluminum. Around me, I have not been able to
find any appropriately sized aluminum can with anything but cat food in it. Pop-top cans require larger slots in the body than
I cut the blanks for the body on a table saw out of 2” x 3” lumber, cutting the taper and the 3 slots. When possible, I assist
the kids in drilling the tuning peg holes in the wood body with a drill press. Sometimes I have them drilled ahead of time
when I am teaching it away from a drill press. The holes can be drilled by hand, too (not recommended for kids under 12
without close adult supervision to get the angle close enough). I drilled the string holes in the metal tuning bolts with a drill
press. The kids sand the body, bridge and nut, pound the nails for the strings, screw in the tuning pegs, glue on the fret
board, gently tap the can into place and then string it. When stringing, turn the peg clockwise to tighten the string, with about
2-3 wraps of string on the peg when it is tight. Very thin strings require more wraps to keep them from slipping. Then I teach
them to play “Mary Had A Little Lamb” on it. They can be real awkward at first, and after a time you can sometimes see the
light go on in their head!
Three times I have had a kid come up to me at a later date, and say he put a pickup on it and plays it in a band on occasion.
click to enlarge
pdf file you can print
pdf file, set to 100% to print the frets
at the right size.
The Cat Can Dobro is a type of slide guitar. I made my plans for this instrument for the Boy Scouts to help them complete
the Music Merit Badge.
One of the requirements of the badge can be fulfilled by making a musical instrument. While there are some simpler
instruments that can be made, I find that the kids really like making this one. Then they have an interesting instrument that can
be played and that they can be proud of. At a merit badge fair I had 9 kids signed up for the morning class, and none for the
afternoon. At lunch, many saw what we were doing with the dobro, and my afternoon class had 23 kids! Help!
A Dobro, resonator guitar
The original Dobro looks like a guitar with a big metal disk (resonator) in the center of the
body of the instrument. This amplifies the sound, and gives it a unique tone. The strings
are raised above the fret board, and the instrument is played horizontally with finger picks
or fingernails for the right hand, and a steel bar to slide with the left hand. The Cat Can
Dobro uses (you guessed it) a cat food can for the resonator. It sounds surprisingly like a
real Dobro. You can play it with a steel bar like a Dobro, or use a narrow glass bottle
neck, like a beer or hot sauce bottle. (If you put an electric pickup on the strings, you
won’t believe the cool sound it has.) The materials for this instrument cost less than a
dollar, not including strings.