I am not a fan of using threaded rods through centering rings. Unnecessary extra weight and questionable added value. I have never seen a rocket fail in a way that threaded rods would have helped. Proper surface prep with 40 grit sand paper, good epoxy (not 5 minute hobby store stuff) is more than enough. If you want more centering ring security at the top glue a 3&quot; section of coupler and fiberglass it to the recovery centering ring. <br><br>If the right materials and techniques are used I don&#39;t feel TR adds anything but extra weight. That is just one opinion. Let&#39;s hear some more. <br><br>Bob<br><br>Congrats on your Black Friday score!<br><div class="gmail_quote"><div dir="ltr">On Sat, Nov 26, 2016 at 1:14 AM Thomas Tweeks Weeks &lt;<a href="mailto:tom@theweeks.org">tom@theweeks.org</a>&gt; wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><font face="arial" size="4" class="gmail_msg"><p style="margin:0;padding:0;font-family:arial;font-size:14pt;word-wrap:break-word" class="gmail_msg">Hey all..</p>
<p style="margin:0;padding:0;font-family:arial;font-size:14pt;word-wrap:break-word" class="gmail_msg"> </p>
<p style="margin:0;padding:0;font-family:arial;font-size:14pt;word-wrap:break-word" class="gmail_msg">So I&#39;m finally going L3... (partially thanks to Black Friday). I&#39;ll leave what I&#39;m building a surprise.. All I&#39;ll say it that I chose a 75mmt kit that will let me cert L3, but also adapt down to 54mm and fly this bird at our monthly launches too.</p>
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<p style="margin:0;padding:0;font-family:arial;font-size:14pt;word-wrap:break-word" class="gmail_msg">That aside, I did want to get some of your (current L3s) suggestions and lessons learned from your L3 builds (and other large project).</p>
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<p style="margin:0;padding:0;font-family:arial;font-size:14pt;word-wrap:break-word" class="gmail_msg">There&#39;s one interesting TRA guy I&#39;ve been following on Fbook who&#39;s got some pretty cool fincan construction and build ideas.. thought some of you might want to check them out and comment. I&#39;m all ears on your big suggestions and lessons learned. Check it out:</p>
<p style="margin:0;padding:0;font-family:arial;font-size:14pt;word-wrap:break-word" class="gmail_msg"><a href="http://www.rocketryforum.com/showthread.php?131007-Level-3-Build-Rocketry-Warehouse-Terminator/page2&amp;s=6803a5849819c8603a81a48356c32a73" class="gmail_msg" target="_blank">http://www.rocketryforum.com/showthread.php?131007-Level-3-Build-Rocketry-Warehouse-Terminator/page2&amp;s=6803a5849819c8603a81a48356c32a73</a></p>
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<p style="margin:0;padding:0;font-family:arial;font-size:14pt;word-wrap:break-word" class="gmail_msg">He uses an interesting three thread-stock rods to pass the recovery forces down through the forward centring ring down to the lower CR too (or thrust plate if you have one). Pretty cool.</p>
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<p style="margin:0;padding:0;font-family:arial;font-size:14pt;word-wrap:break-word" class="gmail_msg">But if you look at his pictures, he also perforates his forward CR a total of five times.. something that makes me nervous. Especially all the force on just one side of the MMT&#39;s CR. Seems more risky.</p>
<p style="margin:0;padding:0;font-family:arial;font-size:14pt;word-wrap:break-word" class="gmail_msg"> </p>
<p style="margin:0;padding:0;font-family:arial;font-size:14pt;word-wrap:break-word" class="gmail_msg">I was actually thinking about doing something similar but using a two super long thread-stock rods and U-bending them form U bolts (four rods) that run the length of the entire MMT.</p>
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<p style="margin:0;padding:0;font-family:arial;font-size:14pt;word-wrap:break-word" class="gmail_msg">See crude diagram:</p>
<p style="margin:0;padding:0;font-family:arial;font-size:14pt;word-wrap:break-word" class="gmail_msg"><a href="http://theweeks.org/rockets/PICS/L3-MMT-rods.png" class="gmail_msg" target="_blank">http://theweeks.org/rockets/PICS/L3-MMT-rods.png</a> </p>
<p style="margin:0;padding:0;font-family:arial;font-size:14pt;word-wrap:break-word" class="gmail_msg"> </p>
<p style="margin:0;padding:0;font-family:arial;font-size:14pt;word-wrap:break-word" class="gmail_msg">Thoughts? Ideas?</p>
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<p style="margin:0;padding:0;font-family:arial;font-size:14pt;word-wrap:break-word" class="gmail_msg">Tweeks</p></font>_______________________________________________<br class="gmail_msg">
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