The fan would have to be external because if it were in the chamber it would be destroyed Yeah I knew that, I've seen pictures of destroyed ones haha Ok, and I just realized I spelled your name wrong both times MrCrowley haha sorry about that. Also, at least until I think of something else, is an a...

Thanks mrcowley, that's exactly what I wanted to know. :D When I finish my cannon which should be in the next month hopefully haha, I'll post some pictures and hopefully videos. Oh and should an aluminum 40 barrel be strong enough(1.5 inch id)? For a ten to fifteen mix? And as far as venting, what's...

Thanks for the help everyone. I think I get it now. But the part that is still confusing me is the back of the piston where or seems that the spool connects and goes through a hole on the back of the chamber which is sealed between the spool with an o ring or rubber seal. Then there's another hole u...

Ok, forgive me because I've been looking around the forums here and I cant find anything that really explains exactly how exactly a piston hybrid works. I've made numerous combustion spud guns (2 spay and prays and 1 metered propane) and really want to try making a hybrid because I've seen some real...