Pumpkin Launcher?

A place for general potato gun questions and discussions.
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Tue Mar 21, 2006 2:47 am

Me and a coupla friends thought it'd be interesting to take potato launching to the next level. On my friends farm he has large drain piping that fits a basketball very nicely and an old hot water cylinder we thought we could use as a combustion chamber. I (being the expert of the trio) thought we'd need to go all out with Propane injection, chamber fans and the like but was kinda stuck on ignition. We don't have stun guns in NZ and I figured a BBQ igniter'd be waaaay to weak for a whole cylinder of propane. Any ideas? Also I'd like a remote for ignition as I'm fairly sure it won't be my safest cannon but I'm not sure how to go about that either. Thanks for your help.
If these plans come into fruition I'll make sure to post pics.
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rna_duelers
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Tue Mar 21, 2006 4:54 am

Now in NZ you might not be able to get a stun gun but any bet you can get a cattle prod(a tazer for cows)they should work well.We can get them here in australia and thats wat i plan to use on my hybrid because i cant get a stun gun.they are quite expensive but about $50 over here,you could always buy one through ebay or something and get it posted to you.
spudshot
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Tue Mar 21, 2006 6:30 am

try ignition coils, flybacks, or camera discharge ignition
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Tue Mar 21, 2006 6:54 pm

Ok cattle prod mite be a bit expensive, so I'll save that as a last resort. Would anyone care to explain to me what spudshot was talking about? I don't know any of those lol.
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rna_duelers
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Thu Mar 23, 2006 4:44 am

A car ignition coil(makes the sparkplug work) and i dont no wat flybacks are and then the use of a camera's flash,not sure how to do it but it can be done.Go for the coil as spudshot said its a good idea but look out or u might get a shock there is a section on this forum on how to do it here is the link

http://www.spudfiles.com/forums/viewtopic.php?t=1653&

give that a try and see how it goes.
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Shrimphead
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Thu Mar 23, 2006 5:24 pm

You can make stun guns. I don't know how good you are at soldering, but anybody with decent experience with electronics should be able to do it (as long as you can get all of the parts). I've seen schematics on here somewhere, many somebody else could post them for you.
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WOW!!
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Thu Mar 23, 2006 5:54 pm

try electric fenceing, they put out 100,000 volts i think,
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theregoesthewindow
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Thu Mar 23, 2006 7:14 pm

A flyback is a transformer used to step up the voltage to operate the CRT, Cathode Ray Tube, (explanation:http://home.howstuffworks.com/tv3.htm.
I would use a camera flash ignition by removing the flash bulb thing and connecting the wires that went to the flash to the ignition screws in your chamber.
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Fri Mar 24, 2006 1:18 am

They all sound good. The next question is: Which would be the most reliable and cheapest? Also would the fact that the hot water cylinder is metal affect any of this? Lastly which would be the easiest to hook up to a remote? Thanks for your help.
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Shrimphead
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Fri Mar 24, 2006 5:20 pm

Remote ignition doesn't mean that you use a remote to fire it. It means that you fire it remotely (from a distance). Basically you just have long wires going to the ignition.
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Fri Mar 24, 2006 11:32 pm

True true. But having a big red button on a remote is so much more satisfying. Ah well I'll see what I can come up with. If anyone has any prior knowledge please post.
bjbrokaw
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Fri Mar 24, 2006 11:43 pm

Even more satifying is a big red button with a red warnnig flipup cover over it and a red LED.
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Shrimphead
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Sat Mar 25, 2006 12:12 pm

You can have a big red button on remote ignition. When you make a stun gun, you take all the needed parts and solder them together in a project box. All that you need to do is to put a big red button as the momentary firing switch. Then you just have long wires running to the cannon for ignition. (And if you don't want to fire it remotely, then just connnect the project box onto the cannon itself and you can have a big red button right on the cannon.)
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schmanman
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Sat Mar 25, 2006 4:10 pm

okay,this is just a crazy idea,but vacum cleaner motors,like all electric motors,create bunches of sparks. so if you mount it inside the combustion chamber and take off the plastic casing,it would put out a bunch of sparks,and ignite alot more gas quicker.But,i've never tried it, i have a pnumatic.I just know about wiring,electronics,ect .

if you mount the spinning shaft so it cant turn,it makes tons more sparks.you can get a vacum from aflea market,thrift store,garage sale for next to nothing.oh, and dont leave the motor on for long if you mount the output shaft solid.[/color]


okay,thanks. it was just a spur of the moment thing, and I just have a pnumatic cannon. I wont recomend that to anybody.but,on mythbusters,they did cause an explosion from gas fumes in a shop-vac using the exact same principal
Last edited by schmanman on Thu Mar 30, 2006 6:49 am, edited 3 times in total.
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boilingleadbath
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Sat Mar 25, 2006 7:46 pm

schmanman, I would suspect that wouldn't work. (one can try, though) The reason being that:
1) it's been tried with smaller motors, and didn't work.
2) There is a minimum gap between 2 plates where combustion can occur; if the gap is too small, it'll go out.
I suspect this is why very small spark gaps don't work, which is a problem which crops up every now and then on the spudtech forums... I suspect that the gaps in a motor will be too small.
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