THEONE Posted May 12, 2012 Share Posted May 12, 2012 (edited) I made a flight test of my high J low K motor today and almost at the end of the thrust it sounds something like boom (watch the video) and i was wondering if this was a sonic boom or any engine failure at the end (Sorry for the bad video)1.zip Edited May 12, 2012 by THEONE Link to comment Share on other sites More sharing options...
gregkdc1 Posted May 14, 2012 Share Posted May 14, 2012 Although I couldn't get the video to work, if your rocket was heading upward when you heard the boom it was more than likely an engine failure. This has been discussed at length in the rocketry community and the consensus is that even though many rockets are going super sonic either the sound of the motor is too loud and drowns out the boom or the boom is focused upward with the direction of the rocket flight. I have seen countless rockets that where know to go super sonic and never once heard what I thought was a boom. In theory you maybe able to hear a boom if a super sonic rocket flew over your head with a horizontal flight path, but why take the risk. Link to comment Share on other sites More sharing options...
THEONE Posted May 15, 2012 Author Share Posted May 15, 2012 (edited) Into the zip file is a .VOB file, try to open it with a program like GOM player or VLC player (the .VOB file) Yes the sound sounds at the end of the thrust but it doesn't looks like it was a CATO Edited May 15, 2012 by THEONE Link to comment Share on other sites More sharing options...
THEONE Posted May 15, 2012 Author Share Posted May 15, 2012 Try to watch it here http://imageshack.us/clip/my-videos/98/di9.mp4/ Link to comment Share on other sites More sharing options...
gregkdc1 Posted May 15, 2012 Share Posted May 15, 2012 Ok I was able to watch the video. I still have my doubts about it being a sonic boom, not that I don't think it is possible but I have seen hundreds of bigger and faster rockets that never made a boom. Is that a sugar motor? Sometimes if the propellant is soft a little chunk, or casing liner can get ejected causing a small explosion sound without the motor actually blowing up. Last did you ever recover the rocket and see if the motor was intact? Link to comment Share on other sites More sharing options...
Juiceh Posted May 15, 2012 Share Posted May 15, 2012 The video cuts rather abruptly after you hear the motor pop... But it looks like the rising smoke trail ends before the video cuts, so I'm going with engine failure. The motor also does not look to be traveling fast enough. I'm not saying it was a sluggish takeoff, it just wasn't as bullet fast as others I've made or seen. Link to comment Share on other sites More sharing options...
dagabu Posted May 15, 2012 Share Posted May 15, 2012 It looks and sounds just like several rockets I have seen blow the bulkhead right after lift off. The recovered tubes shows no failure, just a missing bulkhead or nozzle. Using a press with a 9000 LPI pressure works well to keep bulkheads in place. -dag Link to comment Share on other sites More sharing options...
THEONE Posted May 18, 2012 Author Share Posted May 18, 2012 Yes it is a sugar motor, now the speed depends an the trust and the weight... I was thinking if this is happens because of the suddenly drop of the pressure after engine's cuts out... Link to comment Share on other sites More sharing options...
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