RedAir Posted May 16, 2019 Posted May 16, 2019 What should I put for the target max PSI in the Richard Nakka SRM program if I'm using cardboard tubes? The dimensions of the tubes are 1" ID 1.25"OD 4.125"L and the walls are .125" or 1/8" thick. Thanks, Red
Arthur Posted May 17, 2019 Posted May 17, 2019 Not all tubes are created equal! It's impossible to generalise when you want to make a pressure vessel which shouldn't explode. Collect some samples of certain provenance and test some. Some tubes appeared on the UK market once that were previously rejected by a pyro company for being under strength -the size was right just you couldn't ram a compound inside without bursting the tube. Unless you have pressure test tools you may have to make some guesses and try these in the software, then try to build the simulated motor in the tube that you have.
RedAir Posted May 17, 2019 Author Posted May 17, 2019 (edited) Ok thanks! Are there any cardboard tubes that you know the burst pressure for? Just so I could get an idea Here are the exact one I got. In the video on the site, they show the tubes up close and they look pretty well made. They also claim that the are stronger than the industry standards. https://www.kencolabel.com/products?show=200.010&sku=KSCORE1X4.125 Edited May 17, 2019 by RedAir
Arthur Posted May 18, 2019 Posted May 18, 2019 Another USA supplier gives " Dimensions: 1" ID, 1-1/2" OD, 1/4" wall thickness, " as dimensions for a rocket tube, that's 0.25" wall. And although these are specifically sold for rocket construction there is no burst pressure quoted. Maybe you will have to do some simulations on paper, then do some real life tests. Maybe you will have to actually do tests to see what pressure your chosen tubes can withstand.
RedAir Posted May 19, 2019 Author Posted May 19, 2019 Ok. I will do some tests. Ill probably try something like 1000psi and work down from there until they dont cato
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