Prop taser with light and sound

Components list:

• LED filament purple 3V
• LED filament cold white 3V (I put the LEDs the wrong way up in the schematic)
• Speaker 36mm
• MOSFET 2x (pretty much any N-channel enhancement mode will do - wrong symbol in schematic)
• Schottky diode (not shown; necessary for reverse battery polarity protection)
• 555 2x
• 2n2 capacitor
• 100n capacitor 4x
• 15R resistor 3x
• 3k3 ressitor 2x
• 330k resistor 2x
• 9V battery connector, rugged/hard shell
• Momentary pushbutton 7mm screw fit
• Veroboard (or design your own circuit board)
• 9V battery
• Wiring (I used hearing aid wiring for the LEDs, but any pliable wire will do)
• O-ring or rubber band (optional)

Circuit:

The first 555 produces a ca 50% duty cycle pulse for the LEDs. The second 555 cuts this down to a much shorter duty cycle pulse for the speaker. This sounds better and prevents the speaker form overheating.

The LED colors were chosen to closely match a real high voltage spark. A real spark is slightly more green, but it's only really visible in side by side comparisons. For best results, the purple LED filament should face toward the front, and the white LED filament toward the back.
 

Printing:

Printed on MK4S with the 0.20mm structural preset using PLA

• Print spark tube in vase mode with a brim that closes one end. Use white, translucent or transparent filament.
• Print spark holder halves with the center facing the build plate. No supports.
• Print button holder flat.
• Print box halves with outside towards build plate. Use organic supports for the one with the speaker holes, to keep the battery connector hooks in good shape.
• Print speaker disc with flat side down.
• Print battery holder with big end towards build plate.
• Print collar with organic supports, support enforcer everywhere.
   

Assembly:

1. Put speaker in speaker disc, facing outward. Route wiring through slot.
2. Put speaker disc face down in box with speaker holes.
3. Put PCB in box and connect speaker.
4. Route battery connector, button and LED wires through their respective slots.
5. Clip battery connector to box. The fit is quite snug on the connector I bought. If it is too loose, use glue or modify model. If it's too snug, use better supports or modify model.
6. Screw button to button holder.
7. Insert bottom of spark holder into grooves in box.
8. Insert small lengths of 1.75mm filament into the two round holes in the spark holder. These will keep the holder together later. Don't make them too long.
9. Insert LED filaments in white tube.
10. Insert LED tube in bottom of spark holder, and route wiring.
11. Insert button holder in grooves, so button sticks out of its hole.
12. Insert top of spark holder into grooves in the box cover.
13. Put box cover and top of spark holder onto bottom assembly. Route filament ends into their holes in the spark holder, and squeeze the spark holder together tightly.
14. Add an optional o-ring or rubber band in the groove around the spark holder to keep it snug.
15. Slide collar onto battery holder, glue it there if necessary. Collar is optional, covers joint between case and battery holder. Collar and o-ring prevents disassembly if dropped.
16. Slide battery holder onto box.
17. Watch the polarity when you insert the battery.
18. Bzzz! Have fun!
     

I dedicate this model to the public domain. Use it for anything.