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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-family:"Arial","sans-serif";color:#1F497D'>I was there when it happened and it definitely wasn’t a normal sound. I thought something had broken inside the fuse. Mike landed immediately and we checked everything and all seemed okay including a run-up on the ground so he went up again and the sound happened again but later in the flight (the first time it happened immediately after he broke ground). I’m very familiar with the plane since it used to be mine. I had the same motor but a different controller. Another pilot there said it sounded like an “electric backfire”. I’ve never heard one before, but it sounded pretty scary.<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Arial","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Arial","sans-serif";color:#1F497D'>Verne Koester<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Arial","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> nsrca-discussion-bounces@lists.nsrca.org [mailto:nsrca-discussion-bounces@lists.nsrca.org] <b>On Behalf Of </b>Dave Harmon<br><b>Sent:</b> Sunday, August 19, 2012 5:54 PM<br><b>To:</b> 'General pattern discussion'<br><b>Subject:</b> Re: [NSRCA-discussion] Hacker C50-14XL comp/Castle 80HV Ice 2 combo "backfiring"<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Comic Sans MS";color:#1F497D'>Hi Mike….<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Comic Sans MS";color:#1F497D'>I have noticed a sound like a ‘knock’ on the side of the fuselage on 3 different airplanes, Plett 30-10 and Advance and three ESC…a CC 80HV ICE and 2 CC 80HV ICE V2.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Comic Sans MS";color:#1F497D'>I’ve looked at logs and don’t recognize any problems.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Comic Sans MS";color:#1F497D'>I have always wondered what the sound was…at first I thought it might have caused by the cables to the rudder and elevator slapping the side if the fuse but they are fastened down tightly.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Comic Sans MS";color:#1F497D'>Then…I thought it might be caused by the wheels rattling….<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Comic Sans MS";color:#1F497D'>It seems to happen most of the time on an up line.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Comic Sans MS";color:#1F497D'>It doesn’t seem to be a problem…yet…but I would like to know what is causing it.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Comic Sans MS";color:#1F497D'><o:p> </o:p></span></p><div><p class=MsoNormal><b><span style='font-size:10.5pt;font-family:"Comic Sans MS";color:#1F497D'>Dave Harmon<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-size:10.5pt;font-family:"Comic Sans MS";color:#1F497D'>NSRCA 586<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-size:10.5pt;font-family:"Comic Sans MS";color:#1F497D'>K6XYZ[at]sbcglobal[dot]net<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-size:10.5pt;font-family:"Comic Sans MS";color:#1F497D'>Sperry, Ok.<o:p></o:p></span></b></p></div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Comic Sans MS";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> <a href="mailto:nsrca-discussion-bounces@lists.nsrca.org">nsrca-discussion-bounces@lists.nsrca.org</a> <a href="mailto:[mailto:nsrca-discussion-bounces@lists.nsrca.org]">[mailto:nsrca-discussion-bounces@lists.nsrca.org]</a> <b>On Behalf Of </b>Michael Cohen<br><b>Sent:</b> Sunday, August 19, 2012 3:48 PM<br><b>To:</b> NSRCA<br><b>Subject:</b> [NSRCA-discussion] Hacker C50-14XL comp/Castle 80HV Ice 2 combo "backfiring"<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal style='margin-bottom:10.0pt'><span style='font-family:"Calibri","sans-serif"'>I had a strange problem today with a Hacker C50-14XL comp/Castle 80HV Ice 2 combo. Sounded like the motor/ESC was backfiring, so I stopped flying. I had 56 flights before today, and this is the first time I noticed the backfiring. I was at a contest last weekend, so if it had occurred there, I think people, including me, would have noticed.<o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:10.0pt'><span style='font-family:"Calibri","sans-serif"'>Well, upon taking it home and hooking it up to the computer, I did find that all my settings were still where they were supposed to be, so there was no unexplained change there. I downloaded the data logger, but I really didn’t check it too closely. I then went online to look for backfiring problems and the only thing I found was a sample rate of 10hz (mine was at 1hz) could cause a backfire. I also noted a comment that if you run out of data logging space, that could cause a “ticking”. I did not have a ticking, but I decided to clear all stored logging information and set the sampling rate to "disabled". I ran the motor/ESC for about a minute on the ground with no evidence of a backfire. Could the data logging/storage space been it? Has anyone else had a similar experience? FYI, here is my program:</span><o:p></o:p></p><p class=MsoNormal style='margin-bottom:10.0pt'> <span style='font-family:"Calibri","sans-serif"'><o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:10.0pt'><span style='font-family:"Calibri","sans-serif"'>Brake Strength: 30% <o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:10.0pt'><span style='font-family:"Calibri","sans-serif"'>Brake Delay: No delay <o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:10.0pt'><span style='font-family:"Calibri","sans-serif"'>Brake Ramp: Medium <o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:10.0pt'><span style='font-family:"Calibri","sans-serif"'>Cutoff Voltage: 3.2<o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:10.0pt'><span style='font-family:"Calibri","sans-serif"'>Current Limiting: Normal <o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:10.0pt'><span style='font-family:"Calibri","sans-serif"'>Cutoff Type: Soft Cutoff <o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:10.0pt'><span style='font-family:"Calibri","sans-serif"'>Motor Start Power: low (39)<o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:10.0pt'><span style='font-family:"Calibri","sans-serif"'>Motor Timing: Custom (3) <o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:10.0pt'><span style='font-family:"Calibri","sans-serif"'>PWM Rate: 8khz <o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:10.0pt'> <o:p></o:p></p><p class=MsoNormal style='margin-bottom:10.0pt'><span style='font-family:"Calibri","sans-serif"'>Regards,<o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:10.0pt'><span style='font-family:"Calibri","sans-serif"'>Mike Cohen<o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:10.0pt'><o:p> </o:p></p><p class=MsoNormal><span style='font-size:14.0pt'> </span><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'><o:p></o:p></span></p></div></div></div></body></html>