using GGDT I came up with a peak of less than the 40 psi limit. I also sourced an old oxygen tank today for free while out at a paintball event. I may end up using that for my pressure chamber instead. Hope to have a firing unit next weekend and then start building the carriage for it the following ...

Thank you for that information. I had to poke around to find how to change Flow Coef to Cv instead of %. On to another question. Has anyone tried using a slide gate valve for a breech? I have found a few but they only have a 40 psi rating. I think that would be ok since I am running relatively low p...

Still no idea what the actual pressure I will need to achieve the desired velocity Download GGDT if you want a more empirical basis for your design before committing to the actual build. That looks like a very handy tool, took me a few times to install it (forgot the "run as administrator" option) ...

Looking at the compressor tank I have it is about twice the volume of the barrel. Doing some bar napkin calculations I estimate about 70 shots per scuba tank running at 60 psi. Still no idea what the actual pressure I will need to achieve the desired velocity. I have found a nice QEV from Mcmaster C...

Yeah combustion is out of the question unfortunate. We are looking at about 1800 people with paintball markers, 14+ tanks. and about 10 guys running around with handheld launchers. The Heavy AT (wheeled unit I am building) it the cheapest way to eliminate tanks from the front or sides. I am kicking ...

I was digging in the garage and I found an old tank from a compressor. 6" OD 18" long and I have a 3/4 NPT bung already welded on the one end. I think that will be perfect for this build.

The rockets will be 2 inch diameter. I plan to use HPA regulated down to less than 100 psi.

Do you have any suggestions for what I can use for the expansion chamber?

I am trying to go low budget on this but expect to spend a few hundred before it is all said and done.

I have been lurking here for awhile and decided it was time to register and try to take advantage of the collective mind for a build. I am a paintballer and planning building a wheeled launcher for Nerf Pocket Vortex rockets. The game I am building this for has some requirements I need to meet: Blow...