donperry Posted July 15, 2011 Share Posted July 15, 2011 (edited) So I have been missing from here for some time . I've been busy designing and manufacturing a prototype called "Silverlite'http://img3.imageshack.us/img3/2093/silverlite.jpg http://img204.imageshack.us/img204/3338/img0073myz.th.jpghttp://img20.imageshack.us/img20/2361/nosefd.th.jpg Its a 37 inch rocket with nosecone and airframe made from 1.5 inch drain pipe. Motor is an H class but can be easily changed before or after launch for a more powerful motor I made these nozzles with concrete cement and a paper insert. Measured the angle on the paper with my iPad's protractor Expansion ratio optimized at 0.8 something.http://img819.imageshack.us/img819/8332/img0067dv.th.jpgI hope to achieve 1KM with this lil dude. I'll record video to show ithttp://www.youtube.com/watch?v=9hizGe9h0R4&fmt=22 Edited July 15, 2011 by donperry Link to comment Share on other sites More sharing options...
nater Posted July 15, 2011 Share Posted July 15, 2011 It is neat to see more about sport rocketry here. I just put together an estes kit to see how well they fly on bp core burners and to see if the degn white smoke would be a visible delay fuel for daytime launches. Link to comment Share on other sites More sharing options...
r1dermon Posted July 15, 2011 Share Posted July 15, 2011 What's the dry weight of your vehicle? Link to comment Share on other sites More sharing options...
donperry Posted July 15, 2011 Author Share Posted July 15, 2011 (edited) Dry weight? Weight without fuel? Fuel is 150g so bout 575g Edited July 15, 2011 by donperry Link to comment Share on other sites More sharing options...
alexthegreat00 Posted July 16, 2011 Share Posted July 16, 2011 I noticed in the video that you rocket had a second or two of high thrust (I am assuming that that is the core burning), a pause and then it slowly burns whatever fuel is remaining. I have noticed the same thing with my sugar rockets. Is this behavior normal or is it something that you try to eliminate? If the later, how does it affect the rocket performance and how would I solve this problem? Thanks! Link to comment Share on other sites More sharing options...
donperry Posted July 16, 2011 Author Share Posted July 16, 2011 I noticed in the video that you rocket had a second or two of high thrust (I am assuming that that is the core burning), a pause and then it slowly burns whatever fuel is remaining. I have noticed the same thing with my sugar rockets. Is this behavior normal or is it something that you try to eliminate? If the later, how does it affect the rocket performance and how would I solve this problem? Thanks! The burn pattern in my motor is by design. High thrust of 1.4 seconds propels the rocket. The remainder is the delay grain that will sever a fishline cord inside that will release the spring holding the parachute. It is tested by the rock I tied on the string. You can see the rock falling after 16 seconds or so (video). If yours burn and chuff then you might want to look into the design of your motor. If you are serious you can purchase Burnsim to help with your design. One thing I do is to ensure my core diameter is larger than my nozzle throat. Link to comment Share on other sites More sharing options...
donperry Posted July 16, 2011 Author Share Posted July 16, 2011 It is neat to see more about sport rocketry here. I just put together an estes kit to see how well they fly on bp core burners and to see if the degn white smoke would be a visible delay fuel for daytime launches. White smoke on a bright cloudy day is often hard to see Link to comment Share on other sites More sharing options...
donperry Posted August 6, 2011 Author Share Posted August 6, 2011 The video and details were posted on my blog, here http://rocketryclub.blogspot.com/ Link to comment Share on other sites More sharing options...
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