So now that I've finished this design, I'm wondering if I should have used a stuffer tube for the 13mm mount inside a BT-55 tube, a la the Prime Number Explorer (which has a 9" long BT-5 and a 13 17/32" long BT-55).

It's such a shame, given the deployment velocities. (melodramatic sobbing)


Comments? Please post 'em here.

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__________________
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

Not much difference at all in altitude. But Craig, am I tempting fate with that 1/2A 13mm motor?

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Roguish_Lee_13mm_v2.rkt (44.1 KB, 94 views)

__________________
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

Jay,

The stuffer tube is a safety net for that 13mm engine, it reduces the risk of that parachute not being blown out. Fortunately in both versions, the Dv is so low for the 1/2A3-2T and the A10-3T that you would likely get a clean deploy either way.

I looked at the weight difference between the two versions, and it's only a 16th of an ounce. One mass weight you didn't add in was the screw eye for the nose cone. I just added it to the V2, and the DV rose to 4.46 FPS.

You might play with the length of that stuffer to lower the Dv a little, but I wouldn't worry too much. If this design was meant to answer Solo's challenge, I think it works. The Dv target was 10 FPS or below, so you're in great shape.

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Craig McGraw

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SAM 0044
AMA 352635

It looks tempting, especially for me. I have a small-ish back yard, and having something that flies below 100' would be nice.

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Craig McGraw

BARCLONE Rocketry -- http://barclone.rocketshoppe.com
BARCLONE Blogsite -- http://barclone.wordpress.com
BARCLONE Forum -- BARCLONE Forum

BARs helping BARs

SAM 0044
AMA 352635

Yeah, that's because it's *plastic* Estes PNC-55BB.


I think I'll have to figure out how much room the recovery system needs, and that will be the major determining factor.

This particular design was an upscale riff on the Estes Rogue. And I guess the PNC-55BB disqualifies me since it's not a Semroc part.

But Solo's requirement about using pre-existing laser-cut fins has set my little brain to bubbling... <big evil grin>

__________________
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