Satellite Interceptor is not the same as the Satellite Interceptor (1296 vs 3027)

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les

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For another build I am starting, I ran into an issue and went to check against my 3027 version

Something seemed wrong

So did a little digging and found the instructions for the older version

For some reason, Estes changed the design.

Both have a 16.5" body tube

But the dimensions from the rear of the tube to the various wings/tails changed

The top vertical fin moved from 0.75" to 1"
The bottom vertical fin moved from 1.25" to 1.5"
The wings moved from 2.75" to 3"
The dorsal fin moved from 3.75" to 4.5"

So almost everything moved forward 0.25" except the dorsal fin moved 0.75" forward.

Anyone know why? :confused2: :confused2:

Moving all the fins forward will move the CP forward - typically not a good thing...
 
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caveduck

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That's a very interesting observation. #3027 appeared in the catalog in 2010, right at the beginning of John Boren's tenure. It's possible he would know the reasons. I'm sure there is still sufficient stability margin though. The Crossbow SST came out at the same time; I wonder if has the new proportions?

That satellite has been interepted. :wink:

Seriously though I'd fix the thread caption because this is an important bit of research info and it will be quite a bit less findable if not corrected.
 
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les

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The C key on my keyboard is acting up - sorry
 

EXPjawa

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If I'm not mistaken, its also worth pointing out that the nose cone changed too. The original design had the same conical nose and tailcone as the current Crossfire. With the added base length of that cone and tail extension on the rear, the effective proportions may have changed with it.
 

les

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But the fins/tails did not move proportionally - they all moved 0.25" (except the dorsal fin)

So 0.25 of 0.75 is a 33% change
0.25 of 1.25 is a 20% change
0.25 of 2.75 is about a 9% change

And the new Interceptor has a conical cone with a section in the rear that is straight tubular, which looks like the original. They did eliminate the display only tail cone.
 

EXPjawa

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Sorry, the card image makes it look like they now have an ogive cone. But looking at the actual contents of the package, it is indeed conical. Either way, they saw fit to update the design and make changes. Hard to say why. It would be interesting to see if the body tubes they shipped with were actually the same length in both versions. It wouldn't exactly be uncommon for the lengths of things quotes by Estes to not match the reality. Are the fins themselves unchanged in size/proportion?
 
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