also, does anyone have the burn data for xylitol? id like to use that as
the fuel
Nikolai Nielsen
On Sun, 26 Apr 2020 at 18:13, Nikolai Nielsen <nielsen.nikolai86@xxxxxxxxx>
wrote:
im using motorsim, would it just be safe to use the schedule 40 as the
analog? could it be closer to the schedule 80?
Nikolai Nielsen
On Sun, 26 Apr 2020 at 18:10, Nikolai Nielsen <nielsen.nikolai86@xxxxxxxxx>
wrote:
i dont have any of the sort of equipment to do any of that
unfortunately. im just looking for a rough guideline so i can design
something that i can use.
Nikolai Nielsen
On Sun, 26 Apr 2020 at 18:07, Ray Rocket <dmarc-noreply@xxxxxxxxxxxxx>
wrote:
Note that extruded tubing may not develop a very high hoop strength due
to the axial alignment of grain boundaries during the forming process.
Build a test motor case and run a hydrostatic test. You should be doing
this on homebrew motor cases anyway. A hydro test is easy and cheap enough
to perform, use a grease gun filled with a heavy sugar syrup instead of
grease. This will supply several thousand PSI and is a lot easier to clean
up than actual grease. You'll need to put a couple tee fittings in the
supply line: one to attach a pressure gage and one for a valve. Fill the
casing with water and make sure to purge all the air out of the system
before closing the valve and starting to pressurize.
It is dangerous to test with air in the system. When a failure begins
(say the case begins to stretch just before a tear in the wall begins), as
soon as the volume increases with a liquid filled volume, the pressure
immediately drops. Water can't expand to maintain the pressure, unlike
air. This has a practical side as well, when you can see the how a failure
starts, it is much easier to devise a solution.
Ad Astra,
Ray
On Sunday, April 26, 2020, 09:38:50 AM MDT, Nikolai Nielsen <
nielsen.nikolai86@xxxxxxxxx> wrote:
i want to get back into rocketry and ive got a 2m pole of extruded
aluminium pipe that used to be a tv antenna pole. I want to take a piece to
make a motor casing but have no way to work out the pressure rating and
cant access Richards excel thing for that. can someone help me get an
estimation of its pressure rating? its 38mm OD, 34.5mm ID, 1.5mm wall
thickness
much appreciated.
Nikolai Nielsen
