Okay kids, let's set the WABAC machine for January 2005. After complaining about the price of RockSim for two years, I finally scraped together the necessary cash and bought Version 7 for $95.

I think the first design I implemented in RockSim was a 1.36X BT-55 upscale of the Estes Wolverine #0861. It wasn't long before I started making designs that looked cool, but were impossible to "flight test" in RockSim, given the combination of my enthusiasm and inexperience with the software.

Quite by accident, I discovered that 8 Semroc/Centuri ST-5 body tubes fit nicely around an ST-8 tube. Then, to add insult to injury, I found that an ST-20 would slip around the ST-5x8 + ST-8 assembly. Note picture #1 below. The ST-5 tubes in the "real" models are 3" long, while the ST-20 is 1" long, and centered in the middle of the 3" tubes' length.

One thing led to another, and I came up with the initial design for a rocket I called "5820," (picture #2) pronounced "Fifty-Eight Twenty." ('Cause the body tubes were ST-5, -8, and -20, y'see...) I sat down to build it in earnest, and ran into some smaller than regulation size ST-8 body tubes I'd bought from Totally Tubular *years* before. In the process, I realized that there wasn't *nearly* enough room for a recovery system in the 6" long ST-8 body tube, and decided to Do Something Completely Different(TM).

In recent months I briefly considered using the 5820 tube and ring fin assembly on another rocket, and then chose not to. Fastforward to about 3 weeks ago, when I decided to see if I could put 3 1/2 years of RockSim experience to work on this particular design. I chopped off the front end, since I needed more room for the recovery system, and came up with Version 2 (see below).

About 10 days later, I decided to apply two of Bruce S. "teflonrocketry1" Levison's techniques to the "5820" design: Ring fins and tube fins. I managed to implement them early this weekend, and got the first version that didn't flip end over end -- Version 3. But then I decided while there was *lots* of room for parachutes, shock cords, etc., it still was one of the ugliest things I'd ever seen.

So I decided to make the ST-8 shorter, and ran a longer ST-7 core tube down the center of it. Then for good measure, I added a clear payload bay up front. That gave me Versions 4 and 5, and I decided to apply the now-functional ring and tube fin assembly to Version 1.

That's when disaster struck. I tried to add some commercially available nose weights to the foward end of the original 5820, and it refused to become sufficiently stable. So I decided to leave well enough alone (he says, after FIVE versions of the same rocket!), and release 4 of the 5 on the unsuspecting YORF public.

So I present to you the following Variations on a Single Theme:

5820 A -- Original (for history's sake)
5820 B -- ST-8 Extended with CPT-8 Payload Section
5820 C -- ST-7 Core Tube
5820 D -- ST-7 Core Tube with CPT-10 Payload Section

My typical files will follow in individual posts for each design.

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Attached Thumbnails

         

__________________
Jay Goemmer
"Centuri Guy"/"Tau Zero"
YORF Member 28
Semroc SAM #0029
NAR 86131


"I think about organizing things all the time. Never seems to happen. I find something that piques my interest and I'm off on a quest. Or a Centuri. "

--Bill Eichelberger, 02/22/2022


“Centuri fret buzz in an updated form.”
Bill “Wallyum” Eichelberger re: Estes Flutter-By
03 Sept 2014