2. ATTACH THE SENSORS AND ACTUATORS TO THE BEAM
2a. Clean the beam and abrade it lightly with fine sandpaper.
2b. Epoxy the actuators, foil side down, to opposite sides of the beam 2. 3" from the base end.
Mix 5-minute epoxy separately for each, and spread it in a thin layer. Wear rubber gloves, and apply
moderate pressure until set.
2c. Glue the sensor to the beam in a similar manner, sandwiching
a small, epoxy-soaked square of notebook paper underneath as
an insulator. Attach it 3½" from the base end, to the side with the
actuator’s poled side facing out. This will be the beam’s front.
2d. Solder a purple 30-gauge solid wire between the actuators’
foil leads, and a blue wire between their solder dots. Solder an
8" purple wire and an 8" blue wire to the front actuator’s foil lead
and electrode dot, respectively.
2e. Solder an 8" green wire and an 8" yellow wire to the sensor’s
foil lead and electrode dot, respectively.
2f. Use a multimeter to check resistance and capacitance across each piezo element. Resistance should
read as infinite, and capacitance should measure 24nF ±25% for the actuators and 7nF ±25% for the
sensor. If not, clean any conductive debris that might be shorting out the electrodes.
3. BUILD THE BASE AND INSTALL THE BEAM
3a. Use a hammer and a center punch to knock an insert out of
the outlet box, for the wires to go through (see page 134).
3b. Screw the cap onto the pipe section, and screw the other end
inside the conduit box far enough so it clears the bottom.
3c. Use a stick to stuff the lower half of the pipe with fresh epoxy
putty. Push the beam into the putty until the actuator bottom is
0.1" above the box.
3d. Fill the remainder of the pipe with 5-minute epoxy, until it’s
flush with the top surface of the box.
Make: 139
