I
J
Pin 4
Pin 3
Pin 5
K
L
Fig. I: When current is applied to the solenoid, the
drumstick is pulled down. Fig. J: MIDI jack pins 4 and
5 transmit data to the Drumbot, pin 3 is for chaining
solenoid’s motion to accelerate a drumstick, as
shown in Figures D-I.
Illustration by Tim Lillis; photography by Michael Una
I was able to construct a few different levered
strikers from some spare dowels and K’nex parts
I had lying around. Paper clips and hot glue have
held it all together pretty well, and I used some pipe
strapping to attach it to the drum; you could also
use duct tape or zip ties. I also have a few solenoids
striking the drumhead directly, for accent notes and
short rolls. This is your chance to be creative and
come up with mechanisms that reveal the motion
of the solenoid. Check out automata websites like
dugnorth.com to find examples of simple linkages
that will give a whimsical flair to your Drumbot.
A little wooden striker (cut from the end of a paintbrush) attached to a spring makes a satisfying clack
on my frog-shaped woodblock (Figure K). Attached
to a DC motor, the striker spins once and whacks
the frog on the nose with each MIDI note sent.
4. Program your Drumbot
and watch it beat time.
Once you’ve got your mechanical strikers in place,
multiple devices. Fig. K: A rotary motor spins a striker to
play this woodblock. Fig. L: A solenoid and rotary motor
play this drum.
take the controls of your MIDI sequencer and play
around with different rhythms and beats. The
devices won’t ever get tired, and you’ll find they can
accurately tap out rhythms upward of 200 beats per
minute. (Now might be the time to start that speed
metal band you’ve been procrastinating about.)
I use my Drumbot to replace the drum machine
in my live shows and the audience loves it — the
sound and the sight of a robot drummer are vastly
superior to a lil’ grey box blinking in the corner.
The possibilities from here are endless. With 8
switches, you can control 8 low-voltage DC devices
rhythmically in all sorts of configurations. Circuit-bent devices, kinetic toys, and things that light
up can all be linked and sequenced into a sound-and-light show that’ll impress onlookers with your
ingenuity and resourcefulness. And it’s fun!
Una’s Drumbot in action: vimeo.com/926853
Michael Una is an audiovisual artist working and living in
Chicago. His live shows and installations can been seen in
the United States and abroad. una-love.com
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