the screen was jumping around after somone posted something. Maybe it was just mine, or maybe thats how it is supposed to be....

I believe there were some problems with it. Last time I was in there, it was doing some crazy stuff.

Ok so this site is just eating all my spare time. But that's cool because it is something I enjoy and I learn a lot on here. Anyways, I just wanted to say good job to the admin and moderators of the site. I know it isn't easy to keep a site like this up and running. This place has everything you ...

I was a Radiology Technician for an internship for a couple years. PVC will more than likely show up (havent personally seen it). It won't be as defined as say metal or bone, it will be fuzzy and gray. Doctor's diagnose pneumonia with x-rays...because the fluid in your lungs is more dense than the ...

It sounds to me like your fuel is not combustable like PCGUY mentioned. Without being able to see the gun and try to ignite it, that is all I can think of other than the possibility of the fuel/air mix. Best of luck man, and don't give up.

I remember useing Right Guard in my first combustion, but havent since then. I now use the scent-free Oust air sanitizer. It works fine for me and has a fairly decent smell after it burns.

I use the caulking tubes as well. My combustion will launch those pretty well. Whenever somebody asks me what all I shoot out of my cannon, I just say "Whatever I can find that fits"

I was trying to think of a shotgun type projectile. Just put some wadding down the barrel, pour about 20-30 marbles ...

It never ceases to amaze me how retarded people can be. Take a look at this...
<a href="http://www.9news.com/acm_news.aspx?OSGNAME=KUSA&IKOBJECTID=418f3063-0abe-421a-004f-cf808afd026e&TEMPLATEID=0c76dce6-ac1f-02d8-0047-c589c01ca7bf">Huge Link</a>

This should change your mind about using acetylene ...

Now I haven't read Backyard Ballistics cove to cover, but I have looked at some of the ideas. The ideas are alright, but I have heard from plenty of people that the book is pretty much worthless. It's good for a starting point, but the best part of spudding is the room for your own design and ideas ...

Ok, I dont know how I screwed the post before this one up, and cant figure out how to delete it. Sorry.

So this is the final product (without the letters...don't have time right now). Anyway, hope you like it. The blue looks pretty bright in the pics, but that sbecause the metallic flake in the ...

OK besby, here is what I have done with my cannon. Some people might think I'm stupid for drawing the whole thing out for you, but oh well. Hope this works for you and lemme know if you have any questions.

<a href="http://viewmorepics.myspace.com/index.cfm?fuseaction=viewImage&friendID=4743590 ...

So if my calculations are correct, the volume of my barrel is 113.0973355 in and the volume of my chamber is 56.54866776 in. With those numbers, it seems my C:B ratio is .5:1. Unfortunatly, that is a different ratio than the ideal 1.5:1...But I haven't had any trouble with it. Is it worth trying to ...

Sorry for kicking up an old thread, but I call mine just plain potato gun...like the cheesey ones Pimpmann22 was talking about. That was the first sort of potato gun I ever owned. For a 5 year old, it was awesome. But officially, my cannon is called 'The Eliminator' because I am obcessed with ...

So I was thinking the other day (And gave myself a headache!) and a thought popped into my head. It would be cool to have interchangable, pre-made PVC tubes with compressed air, kinda like a 12gram CO2 cartridge. It may be impractical and hard to do, but it might make portability easier for ...

So I have searched all over looking for information on the C:B ratio, but I can't seem to find anything that will help. Maybe I'm just thinking too hard...who knows. Anyway, if someone could even just point me in the direction of which forum I could find the info in, that would be awesome. I have a ...