Cannons, fireworks, experiments, projects

[patrickg]

Old_Wanker, Well ALRIGHTYTHEN! A belated welcome to the colonies. Please do enjoy the 4th of July fireworks.

I was only in England just one time. I worked in Whitehall for three weeks. Mostly just a few yards from Sir Winston Churchill's wartime command post. It was of course pre-911 and it was somewhat of a "CULTURE SHOCK" for me note the anti-terrorist measures. I had the pleasure of working with some Royal Navy blokes who arrived for work in the morning in uniform but with a civilian sweater over their uniform shirt. They wore their insignia of rank as a tie clip so in theory they looked civillian but how strange to see a bunch of guys show up in shiny black shoes, black socks, black slacks with white shirts and all alike dark ties but all wearing various pull over sweaters. Wonder who this fooled? In theory the IRA (my relatives that I am not too proud of) were supposed to be fooled. I think the disguise would have been about the same as wearing a tri-color rifle target on your back. They show up and take off the sweater and are military till lunch when they don the "disguise" and go across the street to the pub for lunch.

I was much more impressed with their security both outside and inside the building. Anyway, I enjoyed London and the underground. Took a train south almost to the sea but stopped in the sheep country with thatched roof cottages and narrow winding lanes not sufficient for two minis to pass without someone putting their tires on the grass. As I was a passenger with a British contractor driving to lunch at a pub in a nearby villeage I nearly died of cardiac arrest every time we met a car and he dodged over to the "wrong" side of the road. I should have killed us all if I drove. Years of training your reflexes is hard to overcome by conscious will.

Patrick

 

[patrickg]

pbenven, Unfortunately I can't view your attachment, for some reason. I just get mostly a string of Y's with little circles above them. Looks like some Scandinavian letter. Anyway, I never had this problem with other attachments. If it isn't too much bother please try it again.

Patrick

 

[patrickg]

Yowsa, yousa, yousa.... I was "into" U-control flying models as well. I successfuly employed some pyrotechnics. Fired pob bottle and some larger rockets from wing mounts. You need either an insulating bellcrank or an insulating link in the control line. I used the ubiquitous Ford Mod T spark coil to send high voltage up to the airplane. The fuses of the rockets were attached to the aircraft with two small safety pins each. The voltage was applied to the fuse by these connections. the high volts would arc through the carbon in the black powder in the fuse and ignite it immediately. We couldn't aim worth dog doo since the rocket wold fly off on a tangent to the circle and there was uncertainty in where the plane was pointed when the rocket would ignite. Fun anyway. If you perform a "wingover" maneuver and fire the rocket while mostly vertical going down you can hit a target with fair accuracy. Later I graduated to larger rockets and dropping cherry bombs and M-80's. I made a selector switch that was an integral part of the bellcrank. There were sectors of copper seperated by insulator. Depending on the elevator position when the coil was energized, different ordnance could be ignited. Neutral-fire a rocket, climb-fire large rocket, dive-light a couple cherry bombs. You did have to mind the position of the flying wires to avoid them shorting to each other so if you did a couple inside loops you had to do a couple outside loops to untwist the wires.

A friend of mine was quite taken with bombing and modified a beautiful "full on" stunt plane, a Knobler, a beautiful plane with flaps wired reverse to the elevators capable of beautiful stunt flying. He made a bomb bay like an egg crate to carry multiple cherry bombs in separate compartments. Well it seems he didn't do any flight tests with dummy "bombs". He went for the gusto with his version of my "multiple ordnance" selecting bellcrank. I won't drag this out, everyone knows there was a disaster. He pressed the button to connect the battery to the primary of the coil and did some quick maneuvers to exercise the selector switch mechanism. Well for whatever aerodynamic reason, eddy currents or whatever turbulance, many of the lit cherry bombs did not fall out, somehow the G forces did not overcome the turbulance or whatever. It rained doped silk and balsa wood for quite a while. I have had some spectacular crashes, a few in-air failures, one in-air collision in a combat duel B U T never anything remotely resembling this disaster. Even the generously sized fuel tank was destroyed, dumping its alcohol/nitro/caster oil in a fireball. Something hit the wooden prop and it shattered and went missing which allowed the engine to try to achieve relativistic RPM's briefly. Then silence... Not a good day at the flying field.

Later, with some adult participation (WW II combat pilot from Pacific theater who sold funeral plots and burriel insurance) we incorporated missle launches and bombing into RC models.

Patrick

 

[looch]

First attachment was a bitmap, here's a jpeg.

 

[patrickg]

Bazooka sounds neat. We tried to make a bazooka using CO2 cartridges with primitive rocket fuel in them with somewhat mixed results. Didn't get into store bought rocket motors until after I got out of the USAF. Along about the 7th or 8th grade I worked up a design that would fire a blank shotgun shell on impact but didn't have a reliable rocket motor. Estes motors would have turned us into "experts".

Our Polish cannons were hand held, barrels made of tennis ball cans, and fired with regular lighter fluid. Would shoot a tennins ball real good.

Patrick

 

[RobertN]

My uncle built a noise cannon for Fourth of July. He used the hydraulic cylinder off a backhoe. He machined and end cap, complete with facilities for a fuse. He added pivots half way up, to keep the thing from recoiling backwards. This he mounted in a big log he cut out just for this.300gr of FF black powder made a great boom!

Then, somebody said "That hole looks about the size of a golf ball" Uhoh... He tried one, using a long fuse so he could be waaaay back in case the cylinder vlew. It didn't. He made sights for it, and got pretty accurate at 100 yards.

Then, he started just shooting them into the forest behind his house. A few months later, a friend mentioned finding golf balls in an area, about a mile from my uncles; couldn't figure how they got there...

Suprisingly, the thing has held up well for years. He's miked it to check for bulging or expansion of the cylinder case, but it has not budged.

 

[brewerbob]

I was carefully heating sugar and salt peter over a bunsen burner in my dad's workshop while a junior in high school. It blew up and almost burned the shop down. End of rocketry career!
Bob

 

[patrickg]

YO!!! Bobby!!!

There is a small problem with your statement... there is no CAREFUL way to heat sugar and potassium nitrate with a bunsen burner....

Boy howdy, I bet that got real exciting for at least a little while. I was real real real real careful and snuck up on the melting point verrrrrrrrrry slowly and carefully. Why escapes me, I usually just charged right in oblivious to the danger like making nitro glycerin at home etc. Never got hurt doing rockets, worked through that era and came out with all my fingers, eyes, and hearing. Mostly due to blind dumb luck. How else do you use a perfume bottle for a hydrogen generator, light it with a candle flame and inbed strips of zinc metal into a lower kitchen cabinet door with the ensuing explosion and not even break the glass perfume flask EXCEPT for pure dumb luck?

Zinc? Yeah, you prowl around behind old houses looking for their trash piles hoping to find cast off canning jar lids. The old type with milk glass surrounded by a threaded zinc metal outer cover. Smash the glass with a hammer and cut the zinc up with snips. Add an available acid (vinegar if that is the best you can do without messing with your parents car battery) and heat it. Maybe catalyze it a bit with some copper sulphate. And voila, hydrogen gas. Put a baloon over the opening of the container and you can launch a hydrogen baloon with your name and address. Bubble it through a soap solution and you make bubbles that go up instead of down. AND as a bonus you can light the bubbles with a candle. Early bubbles (before hydrogen generator is purged of air) may explode pretty good when lit as do the baloons. Or alternatively, blow up a baloon part way and then finish with hydrogen... Hindenberg reenactments anyone?

I just recalled a physics prof who had filled a baloon with hydrogen and some oxygen (still buoyant enough to float to ceiling) and released the baloon to let it float to ceiling of lecture hall (this before class convened) Then when in the lecture a couple guys dozed off he took an extension pole like window washers use, put a lit candle on the end motioned conspiritorily to the wake members of the class to SSSHHHHH and proceeded to make a grand explosion that surely startled the sleepers and had some folks running around the halls looking for the epicenter of the accident. We never ratted him out and it blew over.

Patrick

 

[TWINKLE_TOES]

Patrick,

I have tried to stay out of this one for statute of limitations reasons, but this looks like to much fun to miss/w3tcompact/icons/smile.gif

Here are a few (author unknown) that probably are safe from prosecution.
First Hydrogen is easily generated with Lye (Sodium Hydroxide) and Aluminum foil. Add the Lye crystals to water in a glass pop bottle slowly and not the other way around. Crumple the aluminum foil so it is long and drop it in the bottle, so it feeds into the solution slowly. Cap it off with a balloon and voila, Hydrogen filled balloon. The amount of lift is small as the Hydrogen will diffuse way to fast thru the balloon wall and the heat of the reaction creates a lot of water vapor and condensation.. (this is a HOT reaction) The good part is lots of Sodium ions available on ignition. Biggest yellow ball of fire snaking in to the night sky you ever saw. Use a Mylar balloon and cool the Hydrogen by running it thru a hose immersed in a cold bucket of water if you want a lot of lift.
(This is not something a sane person should attempt)

For those that cannot afford "Wipets", Nitrous oxide (laughing gas) from 34-0-0 fertilizer.
Fill a beach ball full of this and you’re the hit of the party. Sir Humphrey Davies discovered Nitrous Oxide. His description of the effects, "creates mild hysteria when inhaled" boy did he get it right. Of the five oxides of nitrogen, all but one are poisonous and soluble in water, Nitrous oxide is non soluable and non poisonous. Destructive distillation of Ammonium Nitrate yields the five oxides. Successive bubbling thru water dissolves the bad ones and out the last stage is Nitrous Oxide. Capture this in a beach ball and your good to go, where I no longer know. (this one is far to dangerous for a sane person to attempt)

Al

 

[patrickg]

Yea, Twinkle_Toes. Thanks for ringing in. Yeah, I'm hip to the hydrogen generator you mention but not when I was in grade school. Had I known then I would have been dangerous. Don't think I want to mess with "experiment #2".

A real neat visual and aural display is to take 10 ft of Saran Wrap and tie knots in it every 8-12 inches. hang it up in a safe place suspended over a bucket of water in a good dark location (probably not a closet but outside for fire hazard and fume considerations.) Light the bottom and watch and listen. Ripple is optional.

Patrick