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Old 05-13-2007, 05:55 PM
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Maniac BAR Maniac BAR is offline
Got it bad BAR
Join Date: Mar 2005
Location: Phoenix, AZ
Posts: 160
Default Scrounged-Up Designs

Boy, have I been gone awhile! I think the last time I got into this forum was back around the mid of last year. I now have way too many new Rocksim files downloaded from here! Anyhoo, I have a few to add to the stew. No pun intended!

First up is a neat three stage ring fin I call the Ring Fin Thingy. It has flown three times so far with the first two flights causing a long walk to retrive do to angular staging. Boost on both was fine but as each stage lit, the whole thing went more and more out of vertical. Both flights were with the fins aligned with each other and 1/4 oz. of nose weight.
The third flight was with 1/8 oz. of nose weight added and the fins aligned out of phase with each other. Fantastic flight straight up! Don't know if it was the nose weight or the fins but I was very satisfied with the end result, finally.
The interesting thing with this one is the fact that with the proper engine stack you can acutually fly it in a small field!
The odd thing is the launch rod length. I have flown it all the times with a 48" rod with no problems. The rocket has left the rod straight up and only had the earlier problem when staging.
The ring fin program has the added quirk of adding pylons automatically. That may be the problem with the ring fin vs. the inside tube debate. I had to add the "fins" myself and then used the inside tube trick to get the ring size and fit that I needed.
Although the design doesn't call for any nose weight, I did the swing test with the full stack loaded and it did require a small amout to stabilize properly.
The only main problem aside from the angular staging, has been fin breakage on recovery. The boosters and the sustainer have broken one or more fin joints more than once. The weight of the engine casings is enough to make the boosters tumble rather quickly. The damage has been easily repairable so far. The addition of more glue to the joints may also be the reason for the added nose weight. One thing seems to build on another.

Anyway here are the files:
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Name:  Ring Fin Thingy a.JPG
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Attached Files
File Type: rkt Ring Fin Thingy.rkt (102.2 KB, 137 views)

NAR 85416 L3 as of 4/2010

"There is never enough rope to do the job but it is always long enough to hang yourself up with problems"
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