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Posted: Mon May 03, 2010 10:19 am
by Mr.Sandman
First spudgun I'd ever made, I didn't want to wait 24 hours for pvc cement, So I used caulk. Long story short, after firing over 50 rounds, I decided to use the tighest fitting potato I could find, then when I fired it, The endcap shot off into my "uncomfortable" region.

Posted: Mon May 03, 2010 5:02 pm
by Moonbogg
The first advanced combustion cannon I made was out of ABS. I had the whole chamber build and glued shut, totally sealed. I THEN drilled the holes for the spark gap screws and wouldn't you know, they didn't line up! So, after several attempts to fix and salvage it, I failed epically and had to junk the whole thing. I made another one and used a spark strip instead and made the chamber with a threaded end cap for servicing. The lesson? Be careful or prepare to junk an entire cannon due to a simple noob like mistake.

Posted: Mon May 03, 2010 8:16 pm
by Tidbit77
On my 10' spudgun I placed the barrel support too close to the breech, and had no supports to hold the barrel down. After a while, this placed lots of stress on the fittings connecting the piston valve to the chamber, eventually causing the to fail. The failure resulted in the barrel (still attached to the valve) being thrown 10' in the air when the cannon was shot. Luckily, there was no PVC shrapnelization.

Posted: Mon May 03, 2010 8:26 pm
by Techie
Tidbit77 wrote:On my 10' spudgun I placed the barrel support too close to the breech, and had no supports to hold the barrel down. After a while, this placed lots of stress on the fittings connecting the piston valve to the chamber, eventually causing the to fail. The failure resulted in the barrel (still attached to the valve) being thrown 10' in the air when the cannon was shot. Luckily, there was no PVC shrapnelization.
I managed to launch one of my barrels 20 yards out into a lake earlier today.
FAIL

Posted: Mon May 03, 2010 8:35 pm
by jackssmirkingrevenge
theBOOM wrote:LMAO jack that's funny, did it hurt?
Luckily, as:
An explosion may be defined as a loud noise accompanied by the sudden going-away of things from the places they were before.
... the "sudden going-away" was in opposite directions to my location ;)

Posted: Mon May 03, 2010 8:37 pm
by DYI
And I was a n00b once as well. Luckily, I was only playing around with one or two kilojoules of KE :roll:

I've had my share of minor mishaps. Among them are ABS chamber ruptures (and one barrel, later on), strange issues with steam pressure, two stands shredded by recoil, flash-melting of a barrel, and what are likely the most violent failures of Model T sparkplugs ever achieved without high explosives :lol:

Luckily, after the early mistakes I developed the good practice of standing well back.

Posted: Tue May 04, 2010 12:55 am
by jackssmirkingrevenge
DYI wrote:And I was a n00b once as well.
Ah, who could forget the notorious DYI backstop :D

Image

Posted: Tue May 04, 2010 9:47 am
by kydavies
i built my first vortex cap out of 2 water bottles cut in half and taped together with electrical tape... you can probly guess what happend.

Posted: Wed May 05, 2010 11:01 am
by squishie
this is quite a long but rather fail story of dumb unluckiness

i once help my friend make a cannon that could be aimed by a computer while, he was fiddling with the software i was taking care of managing the cannon and making sure it was good to go and all that. So i started firing it and what not. then my friend comes up and said iv made some changes to the software lets try it out iv added motion tracking lets see if it works. so we boot up the program every things going well we have manual control and motion tracking so we decide to see how good it is at picking up small moving objects so we start throwing stuff in front of it and it seems to be going a good job of tracking it and predicting the path of moving objects. so we wonder how good it would be if the object for instance started changing direction or zigzagged so we got his 5 yea old brother to jump on his bike and ride around and what not, all was good then i decided to yell out FIRE!!! thinking he would shit him self and do some thing funny and the trigger is a big red button like you would find in a factory for like a kill switch so i slammed the button only to realize that the cannon was still loaded..... and then it fired and hit him square in the head luckily he was wearing his bike helmet that went from concave to convex some how he didnt even have a mark on him besides some small cuts and what not.

Posted: Wed May 05, 2010 6:53 pm
by Gun Freak
Wow... you're lucky...

That could have been bad

My friend once shot his little brother with a slingshot shooting an airsoft bb and he got in so much trouble lol

Posted: Wed May 05, 2010 7:19 pm
by clemsonguy1125
I'd stay off the topic of shooting people if I were you

Pump Bottle Shock.

Posted: Wed Jun 16, 2010 5:16 am
by Mpeddlesden
One of my first guns was a pneumatic gun with a "pump" bottle as a chamber and i putt a shotgun wad down the barrel at first fire it didn't fire it out.
The second time i fired it, it did the same so a friend and i opened up the valve and injected air straight into the chamber and barrel the chamber blow up at 95 PSI and i had a shradder valve attached to the end of the pump bottle, when it blew the force broke my wrist and the shradder valve impaled into my wrist just missing my main vain. The pressure put me in a cast and it also made my friend's ears feel like they were on fire.[/size]


(Image of wrist Now ask?)

Posted: Wed Jun 16, 2010 5:57 am
by Crna Legija
i made a combustion that never work until i aimed it at the water tank, it made a marble size hole, but i got plastic welded up before my dad found out. its now been 2 years and i think im in the clear

since that day i made a box that is 50cm thick and full of sand i use it as a back stop.

Posted: Wed Jun 16, 2010 7:38 am
by rikukiakuchiki777
I underestimated the effect of a chamber fan in a spray and pray, and the neighbours house, being downrange but normally OUT of range, was very lucky. A chicken wire fence shredded the potato and saved their window.

I was young :S

Posted: Wed Jun 16, 2010 9:36 am
by squishie
really a fan made that much of a difference?