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