Hi, this is a cannon im developing for a school project. Although its way overkill for the actual task, i couldnt turn down an opportunity to use the schools equipment to machine and weld this
![Very Happy :D](./images/smilies/icon_e_biggrin.png)
It uses 1000psi via equilizing a 2000psi oxygen tank wih the same volume of compressed air (and to the safety nazi's, yes everything is rated for twice that pressure
![Wink :wink:](./images/smilies/icon_e_wink.png)
). Everything is machined and welded already except part of the rear for easy access. My problem is that i can not get the valve to seal properly and build up pressure. Im using a very tough rubber to withstand the 11000 pounds of pressure pushing it against the barrel, but it seems its not soft enough to make the initial seal. I thought this could be fixed by adding an aluminum cone or similiar shape with a rubber coating to the piston head (as shown below) in order to easily make an initial seal on the inside of the barrel, building up pressure until the heavy rubber seal could take the load.
I realize that this is rather insane pressures to work with, so i thought id check with the spud gun community before i go any further.
Any help or advice would be greatly appreciated
ps- im trying to break the sound barrier, as its been broken at only 800psi. If i can get it working, later modifications may include propane and oxygen mixtures of low psi combusting to produce roughly 1000 psi of very heated gas to increase speed... but ill save that for the hybrid section
![Wink :wink:](./images/smilies/icon_e_wink.png)