I would add, hide *under* as well as hide *behind*. That's harder to
arrange, of course, but I once had a steel nozzle fall from a
considerable altitude during a static test that over-pressured. I was
200' away from the test stand and behind an earth berm. The nozzle
landed behind me, about 250' from the test stand. An intact cement (or
graphite) nozzle coming down from a hundred feet or more could equally
do some serious damage.
--Steve
On 3/4/19 12:31 PM, Bill Kuker wrote:
Rick,
Completely agree, distance is non optional no matter what the material, something to hide behind does not hurt either. "And remember this, there is no more important safety rule than to wear these: safety glasses!" Those sharp bits could put your eye out even if they have slowed down considerably.
-Bill
On Mon, Mar 4, 2019 at 1:00 PM Rick Maschek <dmarc-noreply@xxxxxxxxxxxxx <mailto:dmarc-noreply@xxxxxxxxxxxxx>> wrote:
Bill,
" /I also had my first PVC motor CATO experience. It does shatter
into small pieces, but they do not travel far at all because of
their high drag to weight ratio/."
Yes, all my experience with pvc motor cases is that they shatter
into small pieces, sometimes hundreds depending on the motor size.
I call them 'shotgun CATOs'. Lots of fragments that usually don't
travel far. A keyword is '*usually*'. I have found pvc bulkheads
and nozzle assemblies with sharp jagged edged points from the
glued in ends broken away over 100' away.
I'm just mentioning this so people don't get the idea they are
safe to be near when igniting as I've seen the use of 25' long
Estes controllers used to fire sugar EX pvc motors, something that
IS NOT SAFE to do. Not what was done in this photo but I hope you
get the idea. I personally NEVER fire any sugar motor closer than
100' (100' ignition extension cord(s) to the battery are your
friend) and that is usually when standing behind something I can
duck.
Rick
On Monday, March 4, 2019 8:53 AM, Nikolai Nielsen
<nielsen.nikolai86@xxxxxxxxx <mailto:nielsen.nikolai86@xxxxxxxxx>>
wrote:
Well all the motors were made exactly the same. Two had RIO and
katoed, two were plain KNSU and didn't kato. The design works fine
with and without RIO when new.
On Mon, 04 Mar 2019, 5:28 PM Bill Kuker, <bkuker@xxxxxxxxxxxxx
<mailto:bkuker@xxxxxxxxxxxxx>> wrote:
Huh, just a couple weeks ago I went 3 CATOs for 4 motors on a
design that had a perfect 14/14 success rate previously. KNDX
grains were stored in fridge with desiccant for 2+ years. I
always use a KNSU header grain with KNDX for fast ignition,
those grains were fresh.
I also had my first PVC motor CATO experience. It does shatter
into small pieces, but they do not travel far at all because
of their high drag to weight ratio. I already knew this
from... extensive non-rocket pvc exploding shenanigans... but
confirmed it for real. Be safe though, my anecdote does not by
itself constitute a final conclusion on the matter.
On Mon, Mar 4, 2019 at 10:05 AM Richard Nakka
<richard.rocketry@xxxxxxxxx
<mailto:richard.rocketry@xxxxxxxxx>> wrote:
But did these motors have the same safety margin? Perhaps
these motors that did not CATO were more tolerant to
higher pressure.
Richard
On Mon, Mar 4, 2019 at 8:36 AM Nikolai Nielsen
<nielsen.nikolai86@xxxxxxxxx
<mailto:nielsen.nikolai86@xxxxxxxxx>> wrote:
i had some motors of the same size and age that didnt
have RIO and they didnt kato. the RIO is doing something
Nikolai Nielsen
On Mon, 4 Mar 2019 at 16:29, Richard Nakka
<richard.rocketry@xxxxxxxxx
<mailto:richard.rocketry@xxxxxxxxx>> wrote:
My experience regarding long term storage is with
KNSU, KNSB and KNDX. I've used both KNSB and KNDX
after being stored for about a year with no
noticeable change in performance. Storage was in
redundant zip-lock bags at room temperature in a
relatively low humidity environment (approx. 60%
+'/- 10%). I've stored KNSU for long durations in
a zip-lock bag in a freezer with similar results
(this is probably your best bet for storage). As
noted by others, *never *store your grains with
desiccant for more than a week or so. The residual
moisture is sucked out and the burn rate increases
enough such that a CATO could result when fired
(depending on your safety margin). Moisture is a
burn rate inhibitor. I'm guessing but the effect
could be exacerbated by RIO.
On Sat, Mar 2, 2019 at 5:24 PM Nikolai Nielsen
<nielsen.nikolai86@xxxxxxxxx
<mailto:nielsen.nikolai86@xxxxxxxxx>> wrote:
6 months to a year and KNSU
On Sun, 03 Mar 2019, 1:09 AM Ben Brockert,
<wikkit@xxxxxxxxx <mailto:wikkit@xxxxxxxxx>>
wrote:
What is "old" in this context? And is this
KNSB or plain sugar or
sugar/corn syrup or what?
On Fri, Mar 1, 2019 at 8:33 AM Nikolai Nielsen
<nielsen.nikolai86@xxxxxxxxx
<mailto:nielsen.nikolai86@xxxxxxxxx>> wrote:
>
> I've recently observed that old fuel
(atlest fuel with RIO in it) has a limited
life span in terms if usability. I tested
some old motors that had RIO in it and
they all katoed. I also has some old
powdered fuel used for making hand rammed
motors and the the motors that I make now
with it all Kato. I made new fuel and it
worked fine. I suspect that maybe the RIO
catalises some side reactions that makes
the fuel become unstable? Anyone able to
shed some light on what's going on here?
