To propel a projectile at a decent speed one would need a large capacitor bank (large as in small rail gun large). About 500 to 1000 Joules might be substantial enough to propel a small projectile (say, a nail) to a decent muzzle velocity. Now in order to propel a larger projectile (up to 10 grams) ...

So the weather wouldn't cooperate with theGreater and I this weekend which means that we didn't get any work done on the cannon (or shoot it) :( . Velocity3x, the muzzle brake is roughly 1/8" larger than the ID of the barrel. I say "roughly" because theGreater bored it out with an air die grinder an...

Ok, I held out as long as I could so now I'm posting on here .
Here is a video of some fireworks from this past New Year's Eve. It's shot at a relatively slow 210FPS.

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If your feeling froggy you could try the 555 timer Ignition circuit . It works and gets a decently long, hot arc BUT you need some sort of higher current source, like an R.C. battery or two. For simplicity's sake, I'd just stick to what everyone else is telling you and use either the electric BBQ ig...

I never thought about discharging a flash capacitor into a coil. If you put another flash capacitor in parallel with the first one, there should be a larger spark from the ignition coil. As for the "12 or 10 gauge" wire to the spark strip, I've used a little as 16 gauge with a taser and still don't ...

one to keep around the firing range for Murphy's Law and the other to capture the footage

And we spudders know all too well about Murphy's law .

I'd have both of them shooting video "just in case."

For our lighting, we use one of the 500w shop lights. They provide plenty of light for 1,000FPS and are incredibly rugged. I'm pretty sure that I'm not the first to say this but the flames that come out of a combustion gun look amazing with high speed. The Casio Exilim EX-FC100 was the BEST $250 I h...

If you have some RC batteries you might be able to try to make a 555 ignition circuit . I've built this exact circuit with great results and all the components are available at Radioshack, BUT it will drain small current sources in a heartbeat. Personally, for a spud gun, I'd just stick to the elect...

Thank you, thank you, thank you. Hopefully when we go back home we'll get the stand built for the cannon, then this beast will be showcased in the Completed Cannon section of Spudfiles.

(P.S. I was quite speechless when I found out that one of the projectiles went 833FPS )

Here is a video from a beautiful day of spudding. [youtube]http://www.youtube.com/watch?v=leg4PGXLyzU[/youtube] I hope that the video still has sound, I'm currently fighting a YouTube copyright "free use" clause. "Hold On" by Yes should be playing (I thought it was appropriate). It is still some awe...

Here is the video of said test. The muzzle velocity for the 94 gram tennis ball was 769 FPS.
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Tomorrow should prove to be a very destructive day.

Ok. So I did some more accurate speed calculation for the muzzle velocity because the first calculation was approximate (it was made from just three frames). Here is the final muzzle velocity on the ME 1-05. The 7.2 oz projectile traveled 8 Ft. in 12/1000th of a second. That breaks down to 1.5 Ft in...

Nice choice of ammunition. Have you thought about Hornady's Great Plains bullets ?

Here is a video of the cannon that has a full weight projectile (7oz). The high speed at the end is how we measured the muzzle velocity. [youtube]http://www.youtube.com/watch?v=wRbdF_GtbJU[/youtube] I apologize, but I couldn't get around to making some damage pics or videos, there just wasn't anyway...

So yesterday theGreater and I shot Cerberus with a full scale projectile. The sound that came out of the cannon was deafening and we got some very valuable data from this test. This is what we gathered. Muzzle Velocity (approx.)- 650~670 FPS Weight of Projectile- 7.2 Oz Distance (approx) - 175 yards...