also i dont want the fire extingishers weldied to gether although to make it transportable it loses it adapatabilty. i might also wanna have this with only one bottle or mabey three so it keeps my options open.

yeah simplicity and adaptability is main feature. yeah spring assited ball valve is what im doing, seems simple and can withstand the pressure. i also want this thing to last as well, sick of pvc its to weak.

air compressor. plus my dad is a licensed pressure vessel welder so no prob there. previous spud cannons ive made worked fine with tank valve, and cos i wont have to by one makes it all easier but im open to options. and the picture is just a basic diagram overview not a detailed plan (obviously ).

gonna shoot a whole range of stuff. thats why i designed it so its fully customisable (the benefits of threaded parts hey). probably out of smaller barrels big marbles and shaped potatoes. heavier stuff who knows.

yeah sounds good. 3/4" was first thought because its cheaper and provides more pressure. thanks

new spud cannon im deciding to make. consists of two small fire extingisher tanks which go to above 250psi each. two 3/4" nipples from these hook up to 3/4" 90 degree bends to 3/4" tee joint, which then goes to 3/4" tank valve then to the barrel. all of this allows for customisation and ease of use....