November 30, 2002 Meeting Notes
We added another 10 silver screens to the low-loss, all
welded engine (for a total of 70), but it still wouldnt catalyze worth a
damn. In fact, at a tiny throttle
crack, you could see liquid peroxide just dropping out the engine nozzle. We are pretty sure that the silver screens
arent working correctly. We noticed
when we were doing the nitric acid wash that they werent coming out perfectly
white like the last engines screens, almost certainly because we were reusing
the same nitric acid that washed the previous screens, which had turned it a
greenish color. It may even have been
poisoning the catalyst to a degree.
We really need to remember to always do catalyst activity tests
before putting a new engine together.
We can test one of the remaining screens that havent been put in the
engine yet on Tuesday.
I have ordered a supply of fresh nitric acid, which we will
dilute to 10% concentration. We should
be able to just cap off the engine top, flip it over, and fill it through the
nozzle until the entire pack is covered, then rinse it out in a few minutes.
Our first batch of honeycomb core composite panels
arrived. We wound up buying from www.teklam.com, but we also got price quotes
from www.hexcel.com. We are using 1 thick aluminum cores with
fiberglass panels for the box fins on the new vehicle. They weigh 0.69 pounds per square foot. One neat feature of the panels is that the
come with peel-ply on the fiberglass surfaces, so all you have to do is strip
it off before bonding no sanding required.
We found an improved method of cutting the 2 diameter
filament wound tubes. After making all
the measuring marks, we encircle it with a great big hose clamp (two,
actually), and use that as a guide while using the cutoff wheel.
The new engine manifold is done, necessitating our first use
of 1 NPT taps and hardware between the tank / master cutoff valve /
distribution manifold. We arent
worrying too much about optimal plumbing losses, because this vehicle is going
to have far more power than we really need.
Now that I am finally settled in at my new house, I am
starting to bring in big tools for Armadillo.
My wife gets a nice big house, I get a nice big garage and office /
I learned basic machining with a little Sherline lathe and
mill, and have made a bunch of parts with them (Russ has a bigger lathe for the
larger stuff), but I have been looking forward to getting proper sized tools
for a long time. I got a new Jet 14x30
lathe, and a used Sharnoa CNC milling machine.
I have some concerns about used equipment, but it was a pretty good deal
for a machine with those capabilities.
While most of our expected mill work will be conventional X/Y/Z work,
the machine also has a fourth axis rotary attachment, which makes it the
perfect machine for automatic milling of channel wall regenerative nozzles when
we get back to biprop work.
I still have to get them all set up and buy a bunch of
tooling, but they should be making parts soon.
(chips dont make it to the Ferrari)