Updates

Thursday was rather productive. I got the phenolic tubing! Its a 29mm diameter tube about a meter long, with web length (the thickness of the tubing) about 2mm.  I have two of these tubes, enough to make approximately 16-20 rocket fuel grains. 

So as I stated earlier, the purpose of the phenolic tubing is to insulate the aluminum combustion chamber during reaction.  This also has a secondary purpose: it serves as the mold in which I will cast the fuel grains.  This task I will accomplish in the coming days, but only after I have the prefabbed aluminum cases shipped in.  I need to cut the tubing to proper length: too long will waste precious material, too short and the aluminum will be unshielded.

As for right now, I'm ordering a Nitrous oxide valve.  It's the exact same type that is used in automotive racing: you know, the Fast and Furious flames-shooting-out-the-exhaust-pipe deal.  Same piece.  NOS valves are great for high flow, high pressure, and great responsiveness.  The downside is that they burn out fast; anything past 60 seconds is most likely going to fry them.  That isn't a problem for me. The burn time of my rockets will not approach that mark because of the thin web length of the fuel grain. 

This week's agenda is to create fuel grains and start assembly of the entire platform.  Having done the mathematics with my advisor, I know the dimensions of all pieces in this puzzle.  I will then create the pyrotechnic ignition system (the basic idea is to ignite a small grain of fuel with an electric current, then flood it with oxidizer and start the rocket).

More updates/drawings/pics soon to come!