2.AD D SHIMS, IF NECESSARY
The tines need room to vibrate, so depending on
the type of surface chosen and the way the bar is
mounted, you may need to lift the grounding bar
up off the instrument body using a shim. This just
requires 3 more holes using the grounding bar as
The top photo shows shims made of
2" steel bar
and wood square dowels. Plastic, clay, Bondo, Rock
Hard Water Putty, or other materials could be used.
The shims pictured are trimmed and clean, but they
could be made of scraps, rough and with irregular
edges, as long as the thickness is consistent.
The grounding bar provides a way to hold the
tines using easily adjustable setscrews. The bottom
photo shows the bar on a shim with the screw slots
opened. You need a regular flat blade, standard tip
screwdriver, or a driver with a Robertson bit.
3.AD D THE TINES
The tine can be anything that will vibrate and that
will fit the hole. This photo shows a blue tempered
spring steel tine. Crank the screw down tight to
anchor the tine. This grounding bar can hold 12.
Metal tines can be bent away from the instrument to give more vibration room, which makes
it easier to play.
This image shows a grounding bar mounted on a small wooden crate from a
thrift store, demonstrating what’s great about this method: you can use tines in
a variety of shapes, sizes, and materials at the same time.
These tines are made of (from left to right): blue tempered spring steel, hairpin,
street sweeper bristle, unknown steel lattice debris, electrician’s snake, knitting
needle, street sweeper bristle, bicycle spoke, spring steel, umbrella rib, plastic
hobby/craft brush, and plain steel wire with the end splayed by hammering.
The length of a tine determines its pitch. To tune a tine, loosen its screw, scoot
it forward or backward a bit, retighten, and plunk.
You can watch a video of this very roughly tuned thumb piano (shown at left)