Aleckson's
Place
Last updated December 22,
2006
Authored by Scott Aleckson
Scott
&
Cyndi
July
30,
2000
Non-BP Ejection Charges!
The
smokeless powder testing has resumed and entered a new phase. A
new technique
using expendable components is being tested and has worked just as well
as
the aluminum ejection wells in initial bench tests. The
"expendable"
part is standard .223 Rem (5.56mm NATO) fired brass casings that you
can
scrounge up at any shooting range for free. The basic concept is
to
drill out the primer pocket to accomodate the e-match wires and hot
glue
it in place just like it was documented with the aluminum ejection
wells.
Instead of using a separate "burst diaphragm" for containment,
the
powder is held in place with some wadding and the neck of the case is
crimped
flat with a pair of pliers. The pressure must build to the point
where
it will spread the crimp to allow the gasses to escape. The use
of
small caliber rifle brass prevents fragmentation while allowing for an
easily
obtained and expendable container. Work on documenting these
techniques
continues. An updated report will be posted on this website as
soon
as possible. Once something more "final" is ready, it will be
submitted
to Sport Rocketry and notice posted to RMR. A face lift and
reorganizaiton
of this website is also underway, so bookmark this homepage and not the
individual pages contained on the rest of the site.
A new non-BP possibility has entered the
market
recently and a few initial tests have been very promising about a
DIRECT
Black Powder replacement that doesn't require special containment
measures.
The product is the new Hodgden Triple Seven muzzleloading
propellant
(see www.hodgdon.com) that is
listed
as a "non smokeless powder" for direct BP replacement. After
reviewing
several good reports about this stuff used in firearms, I picked up
some
to try out (in both my muzzleloader and for a few ejection tests).
I
made up a half-dozen 1cc charges using various standard methods
(wrapped
up in plastic bag, sluminum foil, paper, etc). I placed one out
on
the ground and pushed the button on the attached launch controller.
To
my delight, it went "bang" just like a BP charge would. A second
try
did the same thing, so I pulled out the pressure test chamber and fired
off
4 more charges in it. They all produced pressures in the range of
60
psi, very similar to that produced by the same volume of Black Powder.
There
are still a number of tests that need to be conducted and I do have
some
worries about ignition reliability. Those should easily be
overcome
by using a good pyrogen coating on your e-matches as opposed to a
simple
nichrome wire or conductive primer. I think I'll pick up a can of
Goex
Clean Shot powder and run the same tests. It may produce similar
if
not better results. Stand by for additional results.
Smokeless
Powder Ejection Charges
See the
Preliminary
Report here (3/10/2002)
My
rocket project for the
Phillips
66
TV Commercial
Video clip
still
available...
Construction
Info
Magnetic
Apogee
Sensor Project
Schematic
using
the Honeywell HMC1001 chip...
Article and
schematic
as posted to RMR
Although still
under
construction, part of the new construction report is posted.
updated
magnetic
sensor report under construction
