For the past three years I have been developing a self-playing
MIDI banjo.  Anyone who has ever attempted to do something like
this knows how difficult it is.  There are no kits, no plans, no
parts.  Everything had to be designed, made or repurposed.

The banjo is a traditional four-string plectrum banjo.  The
instrument fingers 10 frets on each of the four strings.  Little
buttons are pulled with rods and levers by electric solenoids to
finger each string at the appropriate fret.

There are four pickers, one for each string.  They pick the string
in a natural back-and-forth motion similar to the way strings are
strummed and picked by a live person.  Here are links to YouTube
videos of it playing:

  https://youtu.be/vFFgvYYwne4 
  https://youtu.be/qAm1u56IHC4 

When I started this project I naïvely budgeted 6 to 9 months to
complete it.  It took 3-1/2 years because I designed and built 5 sets
of fret assemblies that did not work, and 6 sets of pickers that did
not work, before finally designing and building the systems that you
see in the video.

There are 40 fret assemblies each with its own button, rod, solenoid
and lever arrangement.  This is version six of them.  This version
is the only design with enough force to fully fret the strings and be
quiet enough to enjoy the playing of the banjo.

This is version eight of the pickers.  This is the only version which
can pick fast enough, be quiet enough, on time, and be reliable enough
to play the banjo.

Most of the components were designed with a 3-D modeling program and
printed on a Robo R2 3-D printer.  This allowed the making of rapid
prototypes and rapid improvements on a weekly basis.

Then I had to get banjo music to play on it.  Early in the design
I decided to finger the same frets as played by the Encore Automatic
Banjo of the 1890s.  This way the banjo music for the Encore and for
my new banjo would be compatible.  I was able to convert several of
the songs on punched paper rolls from the Encore banjo into a MIDI file
and they sound great on this banjo.  The two videos shown here are of
original song arrangements.

There are several novel features of this automatic banjo.  The patent
application to protect them was submitted last month.

The local cabinet makers wanted more than nine months to make the
cabinet.  I ended up making the cabinet myself.  It's amazing what
can be done with a biscuit joiner, a router and glue.  The pediment
that looks like a casting is actually a 3-D print.

Overall, it is been a wonderful experience and hobby for the last
several years.  During the next year I plan to play it a lot to find
and correct any reliability issues that arise.  Also incorporated will
be other design improvements and add additional instrumentation.

Hope you enjoy the videos and music.

Wayne Finger