gdeputy Posted April 16, 2019 Posted April 16, 2019 Yes! An over pressured metal case or an under designed metal case will simply fragment, possibly more so at temperature. This is why TRA safety codes require use of 6061-t6 aluminum in cases. They dont fragment, they split open and flatten out. In extreme cases there is still the possibility of fragments, but its extremely rare. I keep a 38mm case that split open in my office to remind me that failure is always an option. I was way too close to that one when it went bang. Folks are doing APCP motors quite often all over the US. I've personally flown up to 'P' impluse motors, which is about 70 lbs of propellant producing around 70,000 NS of thrust. Much larger stuff goes up every year at Black Rock launches. Well, some go up and some go UP. Good times.
dagabu Posted April 16, 2019 Posted April 16, 2019 N was our largest, we got shut down in 2006, &*^&%#$&(*^ ATF!!!
gdeputy Posted April 17, 2019 Posted April 17, 2019 ATF is not in the APCP regulation game anymore. Tripoli and NAR filed a federal lawsuit and won, to get ATF out of regulating non-explosives, like APCP.
Arthur Posted April 17, 2019 Posted April 17, 2019 A properly designed casing is great when used with the right nozzle. There are however youtube tutorials demonstrating how to use PVC pipe and fittings, Which I consider suspect!!! A cato with a bottle rocket of say 10 grams content is a bit different from a cato with a high power rocket with 10 to 50 KILOS of fuel inside.
gdeputy Posted April 17, 2019 Posted April 17, 2019 A properly designed casing is great when used with the right nozzle. There are however youtube tutorials demonstrating how to use PVC pipe and fittings, Which I consider suspect!!! A cato with a bottle rocket of say 10 grams content is a bit different from a cato with a high power rocket with 10 to 50 KILOS of fuel inside. Agreed. PVC is a crappy motor case material, IMO. Yet, lots of people use it.
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