The Roto-Djembe:
What I did on my summer vacation, 2001

So here's the story. I don't really live in the woods, but sort of. Princeton used to be rural, but it's not anymore. There's still lots of woodsy areas, and the deer don't seem to get the fact that malls and yuppie condo camps are taking over the landscape. So some of my grief has to do with the scores (literally) of deer that live in my back yard. But they are cute, and they're also a forgiving audience for many of my experiments, be they musical, lumberjacking, or whatever.

Here's some of
my woods buddies,
triplet deer born
last spring.

I also view them
as potential future
sources of drum heads
(read on).

This was shot from
my back door. These
darlings were about
50 feet away.

Ok enough nature. Let's delve into philosophy and acoustics. "If a tree falls and nobody is there to hear it, it can still make a noise, If You Make It Into a Drum!!"

I wasn't there to hear it, because I was out of town when the winter wind storm caused a huge maple tree to fall in the back yard. The elder tree really was a sacred relic, with a trunk diameter at the ground of about 3 feet. It broke off at a point about 10' off the ground.

Of course my first thought was "firewood!!" So in the snow I went out and lopped off the upper (actually outer, laying well into my neighbor's yard) branches which were already dead and dry, and harvested the rich bounty of burnable wood for the remainder of the winter.

As spring approached, I got a strange idea to attempt to carve a drum from somewhere in the tree. I polled friends who had different types of single-log carved drums, collecting dimensions. I decided to carve an African-style Djembe, and selected a hunk from just below where the tree had broken off. The dimensions I decided to shoot for were 13-14" diameter head, 27" total height (14" base and 13" top "goblet"), 9" diameter at base.

Here is the tree
as it rested in
my yard, with the
chunk removed that
I would use to
carve my drum.
I began hacking away on the tree with my old electric chainsaw, which I had bought 4 years ago when I moved onto the wood-farm which is my house and lot. The little electric dude couldn't really keep up with the tough maple, and my abusive tool-handling style, and the clutch burned out pretty quickly. So I rented a nice 18" gas saw from a local rental place for a couple of days, to get the tree cut up into chunks I could manage. That smoke-belching handheld motorcycle-driven-spinning-blade was so much fun, I went to Home Depot and bought a lovely 18" Homelite, and started in on my drum.

So here's the new
saw, on a hunk of
stump, next to the
beginnings of my
djembe carving

Just to prove
it's really me
carving this drum
(or at least me
sitting next to a
drum in progress).

Notches in the
top to facilitate
hollowing it out

So why don't more
people hollow drums
out of solid trees?

Because the wood splits.
I wrap the drum tightly
and forge ahead.

After carving is
pretty much done,
I haul it inside
and glue the heck
out of it. Giant
hose clamps and
cardboard padding,
carpenter's wood
glue, and a de-
humidifier to help
it dry.

Dry it out some more

Sand it smooth

Prep the surfaces
for staining

Stain it

Seal it with PolyUrethane

So far so good right? Looking like a real wooden acoustic drum now, right? But i'm a music technologist at heart and by profession. And I can't work on something without thinking up things to improve on the design, or at least mess with it a lot. I got an idea to make a "Roto Djembe." What's that?

Well here's a RotoTom.

You can tune it quickly
by rotating it.

Rotating causes a
bolt to push upward on
an inner rim which in
turn pushes upward on
the head.

The bottom of
the RotoTom.

I sawed the lower support
spider to fit inside
the Djembe shell.

Then glued the spider inside
the drum.

This required quite a
lot of routing and moto-
tool work on the inside of
the djembe, to get the
spider to rest evenly,
and to push downward
rather than press outward
on the inside of the drum.

I lined the top of the
djembe rim with

and put the top
roto-rim in place.

A view of the tuning
handle from the
bottom of the drum.

After deciding that it
would be just too
gross to actually
work with a raw
deerskin (see top picture),

I decided to order a 15"
goatskin Aegis Thunderhead kit

At this point, I needed to read up some on how to head and rope african drums. The Aegis site had a pretty good guide on re-heading an already roped drum. I also found a dizzying description which only an eagle scout on steroids could read without passing out. Finally I dug in and began to rope the drum.

Lower ring with
decorative yarn
wrap, and loops
strung for verticals.

Verticals begin.
You can also see
the crown ring
and loops peeking
out from beneath
the fur on the top right.

All done!!
Top shot of
completed drum

Full frontal shot of
completed Djembe.

Gotta tame that unruly
fur somehow. Also
plan on removing
head, putting more
neoprene under roto-rim
(fear lost resonance
due to slit around rim).

So what does it sound like? Not perfect yet, but here's the first recording of it.

News Flash: Roto-Djembe Experiment Fails!!!

Yep, it really sounded like crap. I figured out that the gap under the head after the roto rim raised it up, causing the Helmholtz resonance to pretty much go away, and the neoprene couldn't help much because it was absorbing vibration too.

So i took the next step: I took out the roto junk
and roped up the drum as a regular old djembe.
I also hollowed out the top section some more,
hoping to increase the resonance.

Things were going quite well, almost getting it to sound like a real drum.

Just a couple...
The head broke.

So I got another goatskin Aegis Thunderhead kit

and roped it up again. Things went pretty well this time, and here's the final result:

Listen to it

But, it's still not
as good as a real
Djembe made by a
true master from Ghana.
Here I've shown the
least attractive side
of my drum, next to
a wonderfully crafted
true African drum.

Hear the difference here.
The drums are on
separate stereo channels