Thanks for providing the link to the BATES history article, Rick. I
always enjoy reading about the history of rocketry, and this one in
particular had some interesting and useful info regarding our beloved BATES
grain configuration and rocket motor testing in general.
Richard
On Sun, Oct 30, 2022 at 6:17 PM Rick Maschek <dmarc-noreply@xxxxxxxxxxxxx>
wrote:
Our large 'monolithic' pours have NOT been successful but for reasons
other than melting all at once. On our large successful motors, we use
simple *BATES grains. But because they are so large, they retain their heat
for a long time between pours and stay liquid till completed...we learned
that the hard way after all day casting our first 130-pound grain in
numerous pours (about 35 from 4 cooking pots) and then finding out we
couldn't move the grain into our explosive magazine at FAR for a few hours
till it semi-stiffened.
This is the video of that first grain being poured. Not how from one pour
to the next, the propellant stayed 'liquid' from one pour to the next.
Sometimes the timing didn't work out and we would have 3 or 4 ready to pour
and then a long spell before the next ones were melted and ready for
pouring. This was to also have included how to make big sugar motors
'safely' and Eric shows up wearing sandals and eye protection on his
forehead, no gloves, but it was done in November on a cold desert day.
*BATES grains article I came across recently:
https://apps.dtic.mil/sti/pdfs/ADA405742.pdf
On Sunday, October 30, 2022 at 03:42:58 PM PDT, Bdale Garbee <
bdale@xxxxxxx> wrote:
"Rick Maschek" <dmarc-noreply@xxxxxxxxxxxxx> ("rickmaschek") writes:
We've cast over a few thousand pounds of 'sugar' propellant in a
variety of sizes and shapes with no issue including several over
100-pound grains.
Were these monolithic pours, and if so, what in the heck did you use to
melt that much propellant all at once?
Bdale
