The Halitosis Howitzer

If you want to get people's (especially younger people) attention at your next engine show or backyard barbecue, you just can't beat a small explosion. I've learned that the nanny-state frowns on 1" smoothbore, black powder cannons firing ball bearings through tree trunks so I built a safe cannon (actually a howitzer) that doesn't sacrifice that head-raising CRACK needed to get yourself noticed.

The top from a soft plastic 35mm film canister is screwed to a block of wood. The piezoelectric sparking element is cannabalized from a commercial butane barbecue lighter and its two wires led through holes in the block to emerge into the cannister top (see detail in second photo. Arrange the wires so, when the piezo button is pressed, you get a nice juicy spark across the wires.

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Fuel is provided from a pocket-sized cannister of aerosol breathspray. Spray a bit into the film cannister, immediately mount the cannister on its top on the howitzer, press the piezo button and the cannister will fly twenty to thirty feet with a very satisfying BANG!
The plastic film cannister won't do any damage if it hits something and, with the small amount of propellant, this is actually a pretty safe device.

Aerosol breathspray works well. It contains alcohol and the propellant is butane so it's fairly easy to get a proper mix of propellant and air in the cannister. Non-pressurized breathspray works too but you'll need to experiment a bit to get the right air-fuel mixture. Hairspray works well but leaves a sticky residue. Experiment - but resist the urge to try acetlyene.

If you have younger kids, ensure that they understand that this is Daddy's toy and lock it securely away when not in use.

Oh, one more thing. When testing the piezo element, don't touch the wires. DAMHIKT.

Marv
Tooo Coool

One question, mklotz. Where, in this digital age, do you find empty 35mm film canisters?

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Originally Posted by rlm98253

One question, mklotz. Where, in this digital age, do you find empty 35mm film canisters?

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Cause he didn't toss them in the first place. DAMHIKT.
I'm privy to a world class selection of like-sized Rx containers. Snap cap versions might triple the chamber volume available in a 35mm canister...hmmm

Quote:

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Originally Posted by rlm98253

One question, mklotz. Where, in this digital age, do you find empty 35mm film canisters?

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I have a good deal of trouble discarding any nicely configured small container. In addition, I've worked out several quick ways to defeat those infuriating child-proof caps on containers.

There's nothing sacred about film cannisters. Any small pop-top container will work. About the only consideration is the fact that it shouldn't be hard enough or massive enough to inflict damage or knock valuable antique vases off the mantle.

If you're really safety conscious you can attach a string between the howitzer base and projectile and make it into a "pop + howitzer" = "powitzer".

Boy, that was a real easy Google:

https://www.bing.com/search?q=35mm+f...ZI&form=MOZLBR

Apparently Marv is not the only one who likes to use them. Personally I prefer recycling the plastic pill bottles. Some pharmacies can supply them with the same style of snap cap as the plastic film containers have but you have to request "not child safe". They are transparent enough so you can see the contents. I have actually reorganized my screw and bolt collection with them. Various sized pill bottles hold all my screws from 4-40 up to 12-24. I have them in cardboard bins, one bin for each screw size. Metric too.

Quote:

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Originally Posted by rlm98253

One question, mklotz. Where, in this digital age, do you find empty 35mm film canisters?

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Hugely Entertaining.
I once saw a quote somewhere that said: "Growing OLD is INEVITABLE; growing UP is OPTIONAL"
Just about covers it, methinks?
PS: this is meant as a compliment......

MegaGash
It is taken as a complement, I like having options.
Nelson

Makes me think back about 30 years, we made potato guns like this. Used 40 or 50mm PVC tube and glued on a screw on end cap. Then the same configuration with the wires in the cap. Find a potato that fits loosely in the tube and throw it in from the front, 3 x self tappers about 3" from the cap ensures the potatoes does not upset your firing wires. We used pressurized deodorant as a propellant. Well you can figure it out from here. Not a toy for kids. The potatoes can be shot some 50m depending on the length of the tube and the fit potato to tube you have. Like I say no toy for a kid.:gunfire:, but mechanical engineering students can have a lot of fun. :evil:

Thanks for taking me back memory lane.

Had to edit the post and change 20 to 30....man time is flying.

Memory lane allright! in the sixties we celebrated Guyforks attempt at blowing up parliament & some how added the WILD West. We attached gal house pipe to some 1 1/2 by 3" wood or similar size (very sophicasted use of bending nails over the pipe) and by now you probably know where this is going. the penny bunger was a good fit as well as marbles. two large nails stopped the bunger sliding out the back end but allowed the wick to stick out. We used a hardwood dowel to ram & remove the exploded bunger.I don't know how no one was hurt or houses (except wooden pailings) damaged.
We then progressed to small sky rockets (cost a penny and later a cent) and had a slit across the pipe for the wick (a little tweaking for us kids to finesse) and a solid block at the back instead of the nails. these were much more dangerous as accuracy was lost resulting in some minor injuries to us and pets.

I wont go into the homemade William Tell cross bows we made. If our parents knew what we got up to!

Today the kids play war games on xbox etc.

Cheers

I disavow any knowledge of Potato Cannons...LOL!!

I made a real blackpowder cannon in high school metals class (graduated in 1977). After annealing it, I turned down a hunk of axle from a big truck. It was probably 1 1/2 inches in diameter and 15 inches long. I bored it .75 cal (we had a 3.4" drill.) and included a fuse hole. I rehardened it, polished it all up and built a solid oak "carriage" for it with elevation adjustment. I found wads of Steel wool tamped down in it comes out like a Roman Candle. We've used it to exterminate large flocks of nasty blackbirds by using pebbles of broken automotive safety glass as a projectile. Also set the old man's garden on fire with the steel wool one time. I should get it back out, polish it up and get it ready again.....

Ah yes memory lane, making black powder and filling BB tubes to make fire crackers ( I have the scars to prove it).
Then moving up to filling empty co2 cartridges with black powder! We were worried about shrapnel so I had a piece of CRS 2x4x6 with a 3/4" hole that would take a co2 nicely.
Moving on from a potato cannon powered by hairspray I now have an air powered cannon for launching golf balls ( a good 400-500 yards). I live at the edge of old golf course and have a good supply of golf balls ( found 35 one morning walking the dog). Must have been a lot of duffers, as there were a lot in the woods!
I did make a breach loading BP cannon but it wad stolen from my storage unit, my only hope is whome ever got it will one day get caught with it as it would be classified as a DD (it took a fixed brass cartdridge) 1" bore.

I've never loaded any black powder gun over 8" bore. As far as hand lighting, my limit is about 5".

What is the difference between men and boys? The size of their toys!
Several years ago I build a bowling ball mortar out of an O2 tank. I had it setup to fire with a .22 Blank with lanyard. It would shoot a 16 lb. ball close to 500 yards using about 1/4 cup of cannon powder

Quote:

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Originally Posted by rlm98253

One question, mklotz. Where, in this digital age, do you find empty 35mm film canisters?

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From one of us who still shoots 35mm! Yes mainly digital, but the F2 still gets exercised when I'm in the mood. Film canisters are handy for lots of things, small stuff especially, and stopping loose change wearing holes in pockets. Also fit well in speed-loader pouches with 1/4" foam liners to keep weight on the belt and out of pockets.

My expensive Canon SLR and its complement of equally expensive lenses sits idle in a closet ever since I bought my first digital camera. (I'm on my sixth now.) However, I recognized the possible future uses of film canisters from the get-go so never discarded one.

I schlepped that camera and its lenses around Europe for nine months. Never again. Today I use a 'pocketable' camera with a built-in 30x zoom. It's smaller than the flash unit for the SLR.

Digital is so superior. No in-camera film jams, automatic exposure and focus adjustment, ability to shoot video and a 'film' capacity measured in thousands of shots. But more important to me is having digital pictures that I can view on my computer (no more inopportune slide projector bulb failures), store on a thumb drive and, best of all, arrange and categorize in folders on the computer so I can find a desired image in seconds.

Some time ago I bought a slide scanner and digitized all my slides in one epic and super tedious week. It was worth the effort. I can now view them easily and sort them into something like an orderly arrangement.