A

B

C

D

MATERIALS

Sharpie fine point permanent marker

5"-diameter pin, i" long can be made from a brad

AAAA cell A Duracell 9V alkaline battery is an inexpensive source for AAAA cells, which are stacked up side-by-side in the battery can. Using pliers, peel the can away to reveal the cells, then remove them and snip away their connecting leads.

Soldering iron with 60/40 rosin-core solder

1. PREPARE THE BRASS TUBE With a 5" drill bit, drill a cross-hole as close to the end of the brass tube as possible (Figure A). To prevent the tube from crushing, insert a regular Crayola crayon into the end before you drill.

Electric drill or drill press

Drill bits i" and 5"

Electrical tape

Single-edge razor blade

Brass tube i" OD ×
0.014" wall thickness,
3. 3" long MSC Industrial
Direct part #79800025
for a package of six 12"
pieces mscdirect.com

24-gauge bare copper wire, 2"– 3" Telephone wire works well.

Hacksaw with 32TPI blade or jeweler’s saw

Pager vibrator motor Electronic Goldmine part #G13566 goldmine-elec-products.com

Fine metal file and emery paper

2. SOLDER THE PAGER MOTOR,

REED SWITCH, AND BATTERY

Take the motor, bend 1 lead downward, and solder to an end of the reed switch. Solder a short length of the 24-gauge wire to the other motor lead so that it extends upward and beyond the motor by 1" or so (Figures B–D).

Put a section of coffee straw around the reed switch (Figure E). Slip a plastic soda straw around the motor plus the switch, and add a little extra length (Figure F). Bend the unsoldered lead of the reed switch 90° from its original position. Solder the button end of the battery directly to the lead on the switch (Figure G). The motor/reed switch/battery assembly is complete.

Crayon

Reed switch Electronic Goldmine part #G13078

Plastic coffee straw and plastic soda straw

7" OD flat washer

7" OD light duty compression spring, 2" long

3. INSERT THE ASSEMBLY INTO THE TUBE Slide the assembly into the tube, battery first, until the top of the motor weight is just flush with the

^{Helping hands jig (optional)} tube end (Figure H). Push on the straw to get the extremely helpful assembly into the tube. If the fit is loose, secure with

Super glue a drop of super glue.

86 Make: Volume 13