Hi Dave If you have to fly motor ejection then Cliff's way is good or the Estes way and glue some Kevlar to the side of your airframe, if you don't use motor ejection and use electronics then Aeropack has minimum diameter motor retainers with an eye bolt on top or you can make something custom like the anchor point with holes for motor ejection they both epoxy into your airframe. Jack G -----Original Message----- From: roc-chat-bounce@xxxxxxxxxxxxx [mailto:roc-chat-bounce@xxxxxxxxxxxxx] On Behalf Of Cliff Sojourner Sent: Sunday, January 05, 2014 12:20 PM To: roc-chat@xxxxxxxxxxxxx Subject: [roc-chat] Re: Shock cord attachment advice hi Dave, I've had good results in this situation using about 20 feet of 1/4" kevlar. tie a slip-knot at one end and wrap it around the back of the motor, lead the loose end through the MMT, in to the airframe and tie on the nose cone. the friction & loop are solid enough, the long length gives a soft enough thwak that it won't break anything. personally I have given up on pistons. Cliff On 2014-01-03 17:53, Dave M wrote: > I have a 2.1" diameter Vulcanite that was built per LOC directions where you glue a loop of string down inside the aft tube and then attach the elastic cord. This worked a few times until the elastic cord snapped in two. I replaced the elastic with a Kevlar cord and it worked great. However, I noticed later that one side of the loop of sting that was glued inside the tube had almost broke free (the glue had separated from the tube). I've never built a minimum diameter rocket, but I'm thinking there are better ideas than this to attach the shock cord. Are the min diameter rockets using a piston design i.e. PML? The centering ring for these rockets are too small to make any kind of attachment. > -- ROC-Chat mailing list roc-chat@xxxxxxxxxxxxx //www.freelists.org/list/roc-chat
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