The biggest challenge was to develop twanger mounts that were
orientated 90 degrees from that of the Kalimba to allow "side
plucking", like the strings of a Kora, while still enabling the
sound to be conducted efficiently to the sound-box.
A lot of experimenting has been done with this thing & I
anticipate a good deal more -- check back on this web-site for
updates.
The twangers are plucked on their sides, near (but not at) the
tips.
One nice thing about the field of musical instruments is that by
no means has every musical instrument already been invented!
You or I could invent an instrument a day for a long time to come.
MATERIALS USED
Right and left sides - 3/16" plywood. I found some old panelling
that worked fine.
Front and back - 1/8" plywood. From an old door in my case.
Twangers - 3/16" by 1/32" thick spring steel. I salvaged these from
old lawn rakes. Other widths and thicknesses should
work as well -- lengths would likely be different from
what is shown here. If you used different type twanger
stock, you'd have to experiment a bit to get right
lengths. I have noticed a big difference in volume and
tone by using different gauge & width twanger-stock.
If you get a bad tone with one type, try another.
Twanger mounts - I used 1/4" long hardwood dowel pins bought at
Ace hardware. These are Tietbond-glued into very
snug holes. The middle mounting member for each
of the 21 twangers is a 6 x 3/4" pan-head screw.
"Resonator" - I used a 7" diameter by 1&7/8" high cookie tin.
CONSTRUCTION NOTES
The body is glued together using titebond wood glue and 8 small
blocks of wood in each corner for strengthening.
Try your best to mount the dowels so that the twangers will be as
parallel as possible.
It's fairly critical that the metal screws be located properly so
that the twangers are sprung just the right amount to stay in
place & not let the twangers buzz, but yet not be so "tight" as to
make tuning difficult. I suggest experimenting with some scrap
here before drilling holes in the real thing. If you ever find
that a twanger is loose, or buzzes, an easy fix is to remove the
existing screw & replace it with one size larger diameter.
Twangers can be cut to length simply by breaking them (carefully)
with your fingers while held in a vise-grip. Use a grinding wheel
to round off and dull the otherwise sharp twanger ends.
I found the box as described not to be quite as loud as hoped --
A rather goofy, but quite effective, soundbox was fashioned out of
an old 7" diameter, 1&7/8" tall cookie tin. I silicone glued this
tin to the open top of the instrument (locate this tin as far back
on the instrument's open top end as possible, so not to interfere
with twanging fingers). Then, carefully, using a stout utility
knife, I cut a rectangular hole into the cookie tin's bottom, just
a bit smaller than the large opening at the top of the instrument
wooden part. Into the cookie tin's top I made a 2" diameter
soundhole, positioned as far away from the player as possible (so
as not to be positioned over & thus gazing at the ugly rectangular
hole with it's maw of screw-tip "teeth"). This cookie tin
resonator at least doubles the volume & the tone is quite nice. To
lessen the natural tendency for the tin to vibrate loudly at
certain musical pitches, I wedged what amounts to a sound-post
from tin's floor to inside of the cover - located this as close to
center of the tin as possible --- then secured this post as well
as the entire cover with silicone glue. I may replace the tin with
some sort of small wooden box at a later date, but for now I am
happy with it as is. If I do replace it, it will be for aesthetic
reasons --- altho as you can tell by my webpage, such
considerations have bothered me little in the past.
DIMENSIONS:
- Both side panels measure the same - 6&7/8" heigth & 4&1/4" width.
- Front and back panels measure the same - 6&7/8"" high by 3"
wide at the top, tapering to 1&5/8" wide at the bottom.
- Bottom rectangle is simply cut to fit on the four "wall" panels.
- Top is left open - cookie tin resonator covers the top.
- See illustration for details of handle & twanger mount dimensions.
TWANGER MOUNT LOCATIONS, TWANGER MEASUREMENTS & TWANGER PITCH
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
I am not at all fond of the metric system of measurement, but I
begrudgingly admit that it occasionally can be of some use.
Such is the case here. So all measurements in the chart below,
concerning dowel placement are indicated in millimeters.
LEFT SIDE:
Refer to chart immediately below and to the accompanying
illustration. Note that all 21 twanger mounts are made
identically. Try your best to mount the dowels so that the
twangers will be as parallel as possible to each other and to the
Korimba's top & bottom). Note: this only shows the placement of
one of the two dowels that make up an individual twanger mount The
other dowel is mounted 1&1/2" due left of the first dowel, & the
screw is mounted midway between the two but exactly 1/4" higher
(center-line to center-line).
| distance | distance |
| from the | from the |
left | center | center | | musical
side | of dowel | of dowel | overall | twanger | pitch
dowel | to | to | twanger | vibrating | of this
number | "edge 1" | "edge 2" | length | length | twanger *
--------|----------|----------|---------|-----------|--------------
#A: | 54 | 160 | 165 | 112 | C (2 octaves
(topmost| | | | | below Mid. C)
mount) | | | | |
| | | | |
#B: | 54 | 147 | 140 | 90 | G (2nd G below
| | | | | middle C)
#C: | 54 | 134 | 135 | 84 | A (2nd A below
| | | | | middle C)
#D: | 54 | 121 | 130 | 81 | B (2nd B below
| | | | | middle C)
#E: | 48 | 108 | 119 | 72 | D (1st D below
| | | | | middle C)
#F: | 42 | 95 | 111 | 65 | F (1st F below
| | | | | middle C)
#G: | 36 | 82 | 106 | 57 | A (1st A below
| | | | | middle C)
#H: | 29.5 | 69 | 101 | 52 | C (middle C)
| | | | |
#I: | 23 | 56 | 98 | 46.5 | E (1st E above
| | | | | middle C)
#J: | 17 | 43 | 96 | 41 | G (1st G above
| | | | | middel C)
#K: | 10 | 31 | 93 | 37 | B (1st B above
(bottom | | | | | middle C)
mount) | | | | |
| | | | |
RIGHT SIDE:
Refer to chart immediately below. Note that all 21 twanger mounts
are made identicallly. Try your best to mount the dowels so that
the twangers will be as parallel as possible to each other and to
the Korimba's top & bottom). Note: this only shows the placement
of one of the two dowels that make up an individual twanger mount
The other dowel is mounted 1&1/2" due right of the first dowel, &
the screw is mounted midway between the two but exactly 1/4"
higher (center-line to center-line).
| distance | distance |
| from the | from the |
right | center | center | | musical
side | of dowel | of dowel | overall | twanger | pitch
dowel | to | to | twanger | vibrating | of this
number | "edge 3" | "edge 4" | length | length | twanger *
--------|----------|----------|---------|-----------|--------------
#L: | 51 | 147 | 128 | 76 | C (1 octave
(topmost| | | | | below Mid. C)
mount) | | | | |
| | | | |
#M: | 45 | 134 | 121 | 66 | E (1st E below
| | | | | middle C)
#N: | 39 | 121 | 118 | 60 | G (1st G below
| | | | | middle C)
#O: | 34 | 108 | 113 | 53 | B (1st B below
| | | | | middle C)
#P: | 28 | 95 | 108 | 48 | D (1st D above
| | | | | middle C)
#Q: | 22 | 82 | 105 | 44 | F (1st F above
| | | | | middle C)
#R: | 16 | 69 | 100 | 40 | A (1st A above
| | | | | middle C)
#S: | 10 | 56 | 92 | 35 | C (1 octave
| | | | | above Mid. C)
#T: | 10 | 43 | 90 | 34 | D (2nd D above
| | | | | middle C)
#U: | 10 | 31 | 89 | 32 | E (2nd E above
(bottom | | | | | middle C)
mount) | | | | |
| | | | |
*
The Korimba's overall pitch is one octave below that of a Kora.
The lowest few notes on my instrument could be a bit
louder/clearer. I'm experimenting with different twanger-stock &
will report any findings here. In the meantime, I find these few
low notes sound best if plucked at twanger's end using fleshy part
of your thumb.
If your twangers do not lie as parallel as you would like, the
offending ones can be made parallel by careful, but forceful
bending into shape once the instrument is more or less tuned.
Dowel pins can be trimmed shorter once you see where the twangers
lie.
Looking at the accompanying illustration, it appears that the
dowels are mounted at a slight angle --- this is not the case (it
was just easier to draw it that way) --- the dowel holes should be
drilled perpendicular to the surface of the sides.
Below are pics that were on the CD I used to make available:
These next six photos are not related to the
Korimba article - but I threw them in here
anyways. They are of a Kalimba/Mbira I came
up with that plays (same notes etc) like
a kora. Fun little thing
Dennis Havlena - W8MI
northern Michigan
my webpage: http://dennishavlena.com
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