Re: height of my rocket - help!!!


John Reilly wrote:
al wrote:
Lloyd E. Sponenburgh wrote:
"al" <picricsalt@xxxxxxxxx> wrote in message
news:1152686439.828901.172910@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Al, could you cite the formula, nozzle geometry, tube i.d./o.d., etc?

I really like rockets and drivers that develop their thrust so quickly.

I have an amateur project in mind that requires such instant thrust.

LLoyd

Absolutely.

I had previously dried my strontium nitrate and crushed it to a fine
powder.
the formula is:
Strontium nitrate 55%
Magnesium/aluminum alloy 50:50 -325 mesh 28%
Saran resin 17%

This is screened and mixed well then pressed into the case with 1 ID
increments at a time.

I used standard 1lb BP rocket tooling from Greg Boyd. I rolled my own
tubes, they are 3/4" ID and 1" OD by 7-1/2" long. The nozzle was formed
from fresh step kitty litter. I make the nozzle 7/8" thick. (I bottomed
the tool out and measured 3/4" from that, but realized later there was
a gap from it bottoming and the actual base making the nozzle 7/8" but
I still stick with that.) I pressed a 1-1/4 coloum of the comp above
the spindle for delay, and pressed a 3/4" clay plug on top of that.

I fused it with a length of QM 4-3/4" long, pushed all the way in the
core. I leave about 1/2" on BM hanging out and fold it over to insure
ignition.

This was pressed in my modified arbor press. And of course I had a
reinforcing sleeve.

Hope that covers it all, any questions let me know.

And thanks for the help guys! I really appreciate it!

Well, that blows my comment about chlorine donors with magnesium and
strontium nitrate!! LOL! Seriously though, you can still get a pretty
good red without it, but I'm sure that if you didn't have all that
saran in the mix using a long BP type spindle that they would explode.
As it is, the thrust output you're getting looks EXCEPTIONAL! Thank
you for the information.

John

I also just reread your reply and noticed that it was Mg/Al alloy
instead of Mg. This makes the success of the rockets even more
understandable. Thanks again!

JR

.

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