Noob ? about CG, Estes MP rockets

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Apr 7, 2017
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I have only flown low power, BP powered rockets. I recently purchased an Estes Scion (evidently a "repurposed" Leviathon, came with 4 fins) and it says in the directions that first flight should be on a F15-4 but that recommended composite motors are F50-6T, G40-7W, G80-7T. After reading on here about adding weight to the nose cone as engine size progresses, I am starting to worry about stability as there is no mention of this in the Estes instructions. I guess my question boils down to if this is something I need to worry about or if these rockets are inherently stabile as long as you are using the "recommended" engines?
This kit won't have a problem with any of those motors. A long rocket like this would only become unstable if there was a ton of weight in the back. That would move the CG back towards the CP.

If you want to learn more about all of this, I suggest downloading OpenRocket and start messing around with simulations.

Have fun with the Scion! You're going to love it. I've built two of them. But be's the gateway drug to HPR.
Looks like a stretched version of the Leviathan, with three inverted fins. It's 52" long, you won't need nose weight.
Typically Estes will not recommend motors that will render your rocket unstable, especially in the bigger stuff. So I don't think you need to worry.

That said, I second the motion to download OpenRocket and play around a bit to get a feel for the numbers.
I built a Scion this past winter. I decided I preferred the standard vs the up-swept fins so built it that way. I've launched it on a variety of F motors but really like the F42-4. Don't worry about nose weight. You won't need it.

I haven't tried the Scion, but my Leviathan was built stock and was stable with motors up to an H250G motor in the AT 29/240 case. I would expect the Scion would be stable through the same range, but as neil said, you might want to download OpenRocket and verify.
Thank you everyone for the replies! That's pretty much what I was thinking but my OCD wouldn't let me move forward!