Incline-activated Fireball Shooter

I needed a Christmas gift for a friend who dabbles in magic.  Being an avid Make magazine follower, I thought Kipkay's excellent instructable would be perfect starting point.

Please note, the recipient of this shooter is an adult who respects fire.  The following has none of the safeties/niceties you might expect from professional-grade equipment.  I recommend you do NOT make this unless you are an adult with at least a smattering of common sense.

The idea was to make something he could hide up his sleeve to produce a flash effect at will without doing something as obvious as pressing a button.  To activate the flash, he just has to raise his hand (which seems to be a natural movement if you're about to shoot fire from it).

 I needed:

• 1 single AA battery holder
• 1 mercury switch
• 1 slide switch
• 1 1.5V glow plug
• some Velcro
• about 4 " of 1/2" thin-walled aluminum tubing
• small piece of 1/4" plywood
• flash paper
• flash cotton

I got the tubing and glow plug at a local hobby store.  The mercury switch came from Radio Shack about 20 years ago.  The battery holder came from the Source.  The slide switch came from a defunct Godzilla noisemaker.  The flash paper and flash cotton came from the internet.  The other stuff I had lying around.

Step 1 Construction and Wiring

1. Cut the aluminum tube to length with a hacksaw and grind the sharp bits off.
2. Wire one lead of the battery around the threaded area of the plug and solder it in place.
3. Use pliers to crimp the end of the tube around the plug. (Kipkay's instructable had a better method, if you can find 28 thread nuts, which I couldn't.
4. Mix up some JBWeld or similar and push it into the gaps around the plug. Don't use too much (the coil inside needs to be free and clear and the post needs to stick out the back end. I used locking pliers so I could keep them on for the 20 minutes it took to cure.
5. Hot glue your components to the board, making sure to leave the leads free of glue. I figured the safest method was to have the mercury switch open when the whole assembly was pointed down. The Velcro is under the tube to help angle it out away from the wearer's wrist. The raised end is filled is supported by hot glue.
6. Solder the remaining battery lead to the slide switch, then the other terminal of the switch to one of the mercury switch leads. Solder the other mercury switch lead to the protruding glow plug post. The idea is that the whole thing is wired in series - both switches have to be closed to activate the glow plug.
7. Everything is in place. Do one final test (you've been testing all along, right?), then hot glue over every exposed piece of metal (careful no glue gets into the slide switch - mine was open on the sides).

Glow plug test:

Comments

[fuzzwuzzle]

As the recipient of this particular present I have to say that it works great for exactly the one time shock that you need it for. It conceals up a sleeve very well and the switch on the end means that you don't need to remove it or expose it to shut it off. One of the best presents ever buddy, and they eyebrows will grow back, fire respecting adult indeed. (kidding, of COURSE I'm being careful)

[glassgiant]

Merry Christmas, Shaggy. :)

[Frogz]

aw, when i saw this on hackaday.com i had thought it was using a liquid or gaseous fuel, not flash paper :(
your design needs some improvments
try a spst switch from a microwave(or elsewhere) so you can press a button that'll return to off when it's fired
have a row of 4 of them, 1 for each finger(because everyone knows humans only have 4 fingers) so you arnt limited to 1 shot and if you try to reload too fast, having it explode in your hand http://www.dave-cushman.net/shot/ducksfoot.html
obviously each would have it's own glowplug, you probably could only shoot 1 at a time(aas only provide so much current) but add ATLEAST 1 more barrel

[glassgiant]

Hey Frogz,
Yes, it could be improved further, but a NO SPST wouldn't work well. I wanted hands-free activation (hence the mercury switch). Maybe a rotary selector switch with multiple tubes. The glow plug staying on isn't really a problem. And it cools down quicker than anyone could possibly reload it. I went with Flash paper for safety.

[glassgiant]

Yes, it's hazardous. Kids, ask your parents. Parents, don't be stupid. :)

[lemonie]

Looks hazardous - but also very good.

L