Saturday, December 09, 2006

A test of pop bottles and kite string.

I spent the day fabricating a test tank. I machined some aluminum oring sealed end caps to go on a short length of florescent light tube cover. (Made out of PET or the same thing as a 2 liter soda bottle. )The aluminum end caps were machined with pins on the ends to hold the longitudinal lacing.

The tank ended up heavy with a MR of 3.5 using water, but its small and has a theoretical bust pressure of several thousand pounds. It was not meant to be a flight weight tank as it is short and should be much stronger than needed. Its more of a test piece to see if I can get anywhere near the predicted performance out of spectra wrapped tanks. I suspect that the failure mode when I pressure test it will be to blow out the o-ring seals.

On the left is a picture of the finished tank with a piece of unwrapped light tube next to it.
If the pressure test goes well, I will Ln2 pressure test to destruction. If both of those go well I'll try fabricating a larger more flight weight tank using the same concepts.

I'd taken some project pictures while working on things before I started blogging....
I'll post some of these from time to time...This is a picture of a 600lb Lox ethanol motor injector plate I fabricatedit last summer. We never fired it because we had valve problems and probably won't fire this one until we have more things to test. (Such as an igniter.)


Damien said...

It looks like a bright idea ! I'm looking forward to see how it behaves at high pressures and with a cryo fluid ;) said...

pleas let me know when you will fire it =)