Bill, That is what my calcs suggested and the question of what was the
chamber pressure?
Ken
On Sun, Feb 19, 2023 at 12:12 PM William Claybaugh <wclaybaugh2@xxxxxxxxx>
wrote:
In the absence of any direct knowledge of the wall thickness, fastener
size and both materials I’m not inclined to speculate.
I do find my curiosity directed toward the eight fasteners that appear to
be holding the nozzle to the nozzle bulkhead rather than to whatever held
the bulkhead. Given a report that the end of the tube was undamaged, I’d
wonder if those might be the fasteners that failed.
Bill
On Sun, Feb 19, 2023 at 12:58 PM roxanna Mason <rocketmaster.ken@xxxxxxxxx>
wrote:
According to my back of the envelope calcs and neglecting the throat
area, that's over 75000 LbF/in2 on each bolt and shear strength is roughly
half of tensile so 24 grade 8 cap screws would be at failure at Pc of 1800
PSIG.
What was your target Pc?
Ken.
On Sun, Feb 19, 2023 at 7:31 AM John DeMar <jsdemar@xxxxxxxxx> wrote:
Assuming a 3/8" wall 6061-T6 12" dia case and 24 3/8" hardened cap
screws, the case would tear first at about 1800 psi. If the screws were
only stainless grade, the screws would shear first at 1000 psi. Once we
know the case wall thickness, screw diameter and grade, I can re-do the
calculations.
-John DeMar
Las Cruces, NM
On Sun, Feb 19, 2023 at 3:18 AM roxanna Mason <
rocketmaster.ken@xxxxxxxxx> wrote:
One of two things:
1 - Nozzle attachment system under engineered, or
2 - Grain defect caused an over-pressure.
Did you have instrumentation, i.e. Pc trace? That will discern between
1 or 2.
Ken
On Sun, Feb 19, 2023 at 12:54 AM neutronium95 <
dmarc-noreply@xxxxxxxxxxxxx> wrote:
The 12 inch S motor blew out the nozzle on ignition. I wasn't there,
but a few different videos have been shared around.
This is the best one I've seen:
https://media.discordapp.net/attachments/355526822760415243/1076745130389815346/2023-02-18_sugar_failure_corrected.mp4
-Daniel F.
Feb 18, 2023, 8:13 PM by zeinin@xxxxxxxxx:
What happened at FAR? Facebook doesn't have anything on it
On Sat, Feb 18, 2023, 8:04 PM Matthew JL <prmattjl@xxxxxxxxx> wrote:
Heard about the CATO at FAR today - hope everyone’s OK and that the
setback proves minuscule.
Best,
-Matt L.
On Fri, Dec 16, 2022 at 8:32 PM Rick Maschek <
dmarc-noreply@xxxxxxxxxxxxx> wrote:
We are static firing our 12" S-26,500 KNSB motor tomorrow...total
impulse 355,000 Nsec.
If all goes well, it will be mated with our 10" for a 2-stage to
finally finish Sugar Shot to Space.
Rick