Using a small battery, a magnetic reed switch, and a miniature pager motor, this device will fit concealed inside a fine-point Sharpie pen. When a magnet is drawn near, the contacts on the reed switch close, making the Sharpie dance and vibrate on a table. I call this device the Telekinetic Pen.
The entire device can be built in an hour or two, with only a couple of soldered connections and a little work with hand tools. You can even "prove" it's a real pen by writing with it.
The Telekinetic Pen is a real attention-getter, and as far as the requisite magician's patter and routines, your imagination is the limit.
1. PREPARE THE BRASS TUBEWith a 1/16" 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.
2. SOLDER THE PAGER MOTOR, REED SWITCH, AND BATTERYTake 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.
3. INSERT THE ASSEMBLY INTO THE TUBESlide the assembly into the tube, battery first, until the top of the motor weight is just flush with the tube end (Figure H). Push on the straw to get the assembly into the tube. If the fit is loose, secure with a drop of super glue.
4. SOLDER THE WIRE TO THE TUBEBend the top wire around the tube and downward. Solder the wire onto the outside of the tube and let it cool (Figure J).
After cooling, manually check the rotation of the motor to make sure that the wire does not interfere with the counterweight. If it does, push the wire away with a pencil.
5. COMPLETE THE MODULE ASSEMBLYInsert the spring, then the washer, and finally the cross-pin, which holds everything in place. The cross-pin can be made from a properly sized brad or any type of sturdy metal, and cut and filed to length.
6. PREPARE THE SHARPIE PENPull the Sharpie apart (Figure K). Discard the large ink reservoir. With pliers, remove the writing point from the nose (Figure L), and set the point aside. With an 11/32" drill bit. drill out the nose of the Sharpie to a depth of around 1". Snip the writing point to about 1/4" long, and reinsert it into the Sharpie nose. Now insert the vibrating module into the Sharpie and snap the 2 ends together. Put the cap back on (Figure M). When a magnet is drawn near the pen. or vice versa, it will vibrate.
Neodymium magnets have the best power-to-size ratios of all magnets. and can be concealed easily. A drop of super glue can hold one under your hand, and when you sweep it over the Telekinetic Pen, it'll set it off. The magnet can be peeled off afterward, and any glue remnants will wear away.
NOTE: The Telekinetic Pen will be heavier than a standard Sharpie. so plan accordingly.
- Telekinetic Pen Kit: The Maker Store
(store makezine.com) is offering a parts kit for this project, including a cut-to-length brass tube, the micro pager motor. reed switch, spring, washer, and pin material.
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Brian Dereu is a self-employed manufacturer who enjoys
gadgets, fishing, and family.
Make Magazine Vo. 13
