SpudFiles

This is my latest combustion cannon. It features direct propane injection, a chamber fan and a full automotive igniton system. The ignition system consists of a coil with a module built in that only requires a low voltage signal to fire the 2 spark plugs. the signal is provided by a sensor that puts out over 100 signals per second. The idea for the igntion system was provided by my friend Larry who is a master mechanic. The gun also features a 24" long 4" diameter chamber with and over under configuration and a 6 foot long 1.5" diameter barrel. It kicks like a mule and fires like a champ, every time. Approximate distance reached at a flat trajectory is 100-150 yards. It shoots about 2 city blocks at a 20 degree angle. I also added a custom flame paintjob to the chamber that is black with red flames.

sounds cool, i'd love to see some pics of that, you seem to have gotten along well especially if you're a semi newb, most people dont get very advanced unless they hang around the spudtech forums

propanepower wrote:The ignition system consists of a coil with a module built in that only requires a low voltage signal to fire the 2 spark plugs.

How do you do that ive always wondered how you do it but have never been able to do it. The low voltage thing where you make it turn on a stronger current. Ive wanted to do this but not for a potato gun it was for a model rocket. I had two ideas one was to hook the alarm part of a clock to the rocket which would make it go off what ever time you set the alarm for. And the second idea was to hook it up to a cell phone and when ever you call the cell phone the rocket goes off. Please someone tell me how this is done. Thank you. By the way cool gun i would love to see a pic. Hopefully all that made sense.

thanks for the intrest in the ignition and my gun

spudshot: this might not make sense for most people but this is the way my igniton works
an automotive coil that has a module built into only requires a low voltage signal in order for it to fire, thus the module (yes two different modules one is in the coil the other is called a MAP sensor) the MAP sensor reads engine vaccum and sends a pulsed signal to a cars onboard computer. this one in particular sends a 159 hertz signal at 0 inches of vacuum or when there is nothing hooked up to it. so the coil is acutally trying to fire 159 sparks per second but it really cant keep up that fast so it is more than likely around 80-100 sparks per second.

pimpman22: the way you could possibly accomplish this is with a relay in place of the speaker on an alarm clock and then have your high current battery or your ignition source hooked up to the other side of the relay thus it would take the low current as in amps (not low voltage) flow and can increase it to a high current flow this is the only way i can think of on how to use an alarm clock

also the pics should be coming soon, they were too large in size and had to be reduced and pcguy said he could do it for me since i am not a computer whiz, just a mechanic/spudgunner who knows plenty and wants to know plenty more

Added the images

Thanks a million-billion propanepower. Your gun is freakin awesome (how much did all that cost?). I know a fair amount about electronics and electricty but what you said was way over my head. I kind of understood what you said but please dumb it down for me (im dumb). Nicely done i will give a 10 (this is the first time ive gave some one a ten). Like the paint.

VERY well done, even better than i thought it'd be, if you arent already registerd, you should register on the spudtech.com forums, i'm sure some others'd love to see that. i'm waiting to see what a pneumatic from you will look like

pimpman22: if you want me to explain it in dumb its gonna take me a while to think of how to say it. so i will think of how to say it and get back to you. thanks for thinkin my gun is sweet. hopefully i will get a small video of the shots pretty soon.

oh yea and if i had to buy the coil and the map sensor(one was a junker and the other cant stand the heat of an engine compartment) it would have cost me around, 75 for pvc and propane, 25 for electronics (wires switches + project box), the coil would have been 65 at my cost (my dad own a repair shop so we get a discount) and around 50 for the map sensor my cost. so over $200

Reall nice cannon, Sweet ignition system. DEFINATLY join http://www.spudtech.com

i am on spudtech.com i just need to figure out how to load my pictures

If ya'll could please rate my cannon and tell me how good it is. ya know cause i wanna know how it measures up to everybody elses

what are the campy things that you have used to secure and detach the barrel called?

Those are called camlocks. They allow the easy changing of barrels because they just unclip.
Be aware that this topic is 4 years old. It might have been better to look at other cannons to see if you could find a named example, although I understand its hard to search for something you don't know the name of .