$0 combustion

Billy Bob · Sun Jul 08, 2007 4:44 am

very nice gun good work.

The woodwork impressed me to do the same when i will build a new gun.

Scotty · Mon Jul 09, 2007 10:00 pm

Off topic banter,

Hoff is kinda cool, but that shot just looks so gay,
I'll give you all my bux if you change it!

Peace
Scotty

paaiyan · Mon Jul 09, 2007 10:27 pm

Well that's a pretty awesome cannon being that it's made out of scavenged parts. SO what's the farthest shot you've made? Oh, and props for the Ray Charles photo.

Racuda · Mon Aug 27, 2007 9:09 am

u have a big head

n3rdkw · Thu Aug 30, 2007 6:23 pm

Geez... this thing is a BEAST.
I'll bet the recoil is larger than a 12 gauge shotgun
How fast does it go?

Fnord · Thu Aug 30, 2007 6:54 pm

^^Well, there was one time when I didn't get my footing right and it almost knocked me over backwards...

Potatoes go 250-300 fps, and lead goes much slower. Probably like 150 fps.

iknowmy3tables · Thu Aug 30, 2007 7:10 pm

I see you streamlined it for cheapness, I do a lot of cheap stuff since no one wants to drive me to a good hardware store and wait for me to finish shopping
oh and how did toy plug the barrel side of the chamber

Fnord · Thu Aug 30, 2007 7:20 pm

oh and how did toy plug the barrel side of the chamber

Toy plugged the chamber by cutting out home-made sheet pvc plugs with a dremel and belt sander.

n3rdkw · Thu Aug 30, 2007 10:41 pm

Wow, I thought your cannon would go faster than 300 fps. I mean, the thing really looks like a beast and the damage shot looks more than 150 fps from lead. But iono.
I achieve my fist real damage shot today by shooting a carrot through a tin coke can.
Well, I stuck a nail into the carrot and the nail went through but the carrot... dissappeared.

Fnord · Fri Aug 31, 2007 7:59 am

Well, I could be wrong about those numbers. They were calc'd with evbec, so they could be off. If I had to take a guess by eyeballing it I'd say it shoots a little faster (maybe 350?), but I was just being conservative.

(But still, a half kg chunck of lead going 150fps is still very damaging)

n3rdkw · Sat Sep 01, 2007 10:07 am

Haha, Ya half a kilo of lead IS very lethal at 150 fps.
Actually, just film yourself firing a potato straight up and time how long it takes for the potato to go from ignition to landing.
Divide the time by 2 then you use distance = 1/2 * 9.8 (m/s/s) * time^2
to find how far it went up.
Then you use Acceleration = change in velocity / time
Acceleration = 9.8 m/s/s
time = your calculated time
then use that to find the change in velocity, which should be the muzzle velocity of your potato in meters per second