Nobody appreciates a good knurl more than the
engineers at
MaxCo.
Traditionally, a knurler was a highly-skilled employee
who, with
the aid of his quartz-tipped briding-point, would
painstakingly
carve those strangely attractive yet functional regular
grooves into
metal surfaces, turning
them into everyday works of art.
Nowadays, of course, knurling is done using machine-
tools such as
the Knurlmaster, usually under computer control.
Howevertheless, contemporary knurlers are missing a
trick.
Modern machine tools typically have resolutions down in
the
micron range, and can be controlled quickly and
precisely.
This opens up the option of making knurling that is more
than just
decoratively functional. An audio signal, fed to the
knurling
machine, can be used to modulate the knurl depth. The
resulting
Audio Knurling can be played back simply by tracing a
piece of
metal swarf along the helical path of the knurl.
Of course, most knurling consists of multiple parallel
lines, usually
running in two opposite helical directions (known, should
you be
wondering, as Nepalese knurling, after a
misunderstanding on
where it originated). This provides the opportunity to
encode two
independent pieces of music (left and right handed),
each with
multiple tracks, to be played using a suitably fine-
toothed comb.
Finally, it is worth pointing out that the threads of
screws and
bolts can accommodate simple monophonic recordings,
with
particularly bass-rich tracks providing extra grip.
Post-finally, I should perhaps mention that we have
recently
prototypified a rifled rifle barrel which, on firing,
produces a
0.3msec excerpt from Wagner's Ride of the Valkyries.