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.)


2 comments:

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 ;)

sky_chaser.blogspot.com said...

pleas let me know when you will fire it =)