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> 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> 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>
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>
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> 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>
wrote:
6 months to a year and KNSU
On Sun, 03 Mar 2019, 1:09 AM Ben Brockert, <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> 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?
Attachment:
CATO at NARAM years ago.jpg
Description: JPEG image
