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-   -   Estes NASA Pegasus center of gravity (http://www.oldrocketforum.com/showthread.php?t=16342)

aeppel_cpm 11-23-2016 04:25 PM

Estes NASA Pegasus center of gravity
 
Does someone have an Estes NASA Pegasus they could check location of the Center of Gravity for me, please?

I'm working on a downscale, and planning on using 13mm Bs in it. I figure it could use some nose weight - but how much? If the original instructions list the Cg, I don't see it.

Charles

mwtoelle 11-25-2016 05:53 PM

Personally, I would clone the kit and use the CG from it to figure out where it needs to be for upscales/downscales. Unfortunately, Estes generally does not give out CP/CG info on their kits.
Just my 2 cents.

aeppel_cpm 11-25-2016 06:05 PM

I suppose that would work. Or I could fetch my original back from my mother - she found it in the attic last year.

I had forgotten that Openrocket is attempting tube fins these days. I was reminded on the forum that shall not be named. OR suggests the Cp is a bit behind the leading edge of the wings. So the Cg should be near the front edge of the side tubes.

Downscaling is fun - but I think it's prone to weight issues. This little fellow is going to take a bit of noseweight.


Jerry Irvine 11-25-2016 06:08 PM

The Estes kit is overtable by design.

aeppel_cpm 11-25-2016 08:25 PM

Very probably. But I suspect that the BT20 balsa nosecone is lighter (in proportion) than the plastic BT55 original. And I'm shoving a heavier motor in, too.

It should be minimally stable as I've built it, with a washer on the base of the nosecone. I hope to test that soon. The corn is off the fields!


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