Over at http://www.oldrocketforum.com/showthread.php?t=15334 I posted about my new cone stabilized finless rocket, the Rxiiiab, and there's mention of some other similar rockets: the Arcturus and Candlestick from ca. 1970 Model Rocketry, a design from a ca. 1970 American Rocketeer, the SAI Vulcan, the Hot Rod Bell Bottom, the FlisKits Mighty Saturn V, and the Odd'l Rockets Flare. I wrote more about some of these at https://richsrockets.wordpress.com/...-some-thoughts/ , and J. Steven York had some interesting comments here https://plus.google.com/11829105631...sts/e9GEdBnsJVd

Anyone else have insights? Particularly about stability. If the Barrowman CP is relevant for these designs, then it seems the ca. 1970 ones all had significantly more nose weight than is needed — even if you don't include an adjustment for base vortex drag, which would pull the CP even further back. On the other hand, York says "I've heard from some people the cone stabilized rockets are very susceptible to angle-of-attack problems, and can seem stable until something (wind, off-center or deflected thrust, ...) kicks them off straight and true. Then they go all to hell."

The Rxiiiab seems quite nose heavy, tending to impale itself lawn dart style even after deploying the streamer, and I'd like to try reducing the nose weight. But I'm already using less nose weight than one would probably expect based on the ca. 1970 designs, and York's comments suggest it may be best not to go there. Any thoughts?

__________________
Rich Holmes
Camillus, NY
Secretary / newsletter editor
Syracuse Rocket Club

http://richsrockets.wordpress.com

One of our High School "kids" flies these cone stabilized rockets all the time at our club. I think he has even staged one. Plenty of base drag down low keeps them stable. Fins are over rated and the old folks are real scared of anything even slightly non traditional. Cone stabilization is kid tested, mother approved. He has since moved on the flying soccer field rockets on high power motors, now there is some massive base drag!