This week I'm building the Rocketarium Frangible ARCAS. My question is regarding the "explosive sheet section"--the 2.125" long tube that's slipped over the BT-60: for scale purposes, should this short section of tube be bevelled at the front and rear? I can't seem to find any photos of a real frangible ARCAS and even ROTW makes no mention of the round.

Thanks!

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Never trust an atom. They make up everything.

4 out of 3 people struggle with math.

Chemically, alcohol IS a solution.

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An article in Sport Rocketry Sep/Oct 2020.

Not much detailing but unique in its own way.

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That?s very helpful. Thanks!

__________________
Never trust an atom. They make up everything.

4 out of 3 people struggle with math.

Chemically, alcohol IS a solution.

NAR# 94042
SAM# 0078

Either a really difficult finish to duplicate or pure luck on a botched paint job?

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That does indeed look like a very rough fiberglass layup job. I wonder why it was done (seemingly) so sloppily.....

Earl

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Earl L. Cagle, Jr.
NAR# 29523
TRA# 962
SAM# 73
Owner/Producer
Point 39 Productions

Rocket-Brained Since 1970

I'm going to be making look FAR neater than that.

I've had an epiphany!

Years ago I bought a packet of Estes centering rings and paper adapters--now I know why.

The largest adapter goes from BT-60 to MC (I have NO idea what MC means.) I cut out (2) of the BT-60 to MC pieces, glue them into rings, and then smooth and shape them with the handle of a paint brush against my Heculean right thigh (a.k.a "Thunder". The left one is "Lightning".)

Fortunately I didn't assemble the upper body tubes onto the lower body tube and this allows me to slip the formed rings from opposite ends and register them against the center "fat" section.

What I still need to do is either build up the center "fat" section to match the rings or reduce the rings to match the "fat" section. I've not glued anything yet--so all possibilities are on the table.

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__________________
Never trust an atom. They make up everything.

4 out of 3 people struggle with math.

Chemically, alcohol IS a solution.

NAR# 94042
SAM# 0078

OK, I'll probably fall out of favor with the "scale Gods" for this, but this is what I've done: I've slit and then wrapped several layers of adhesive-backed label paper around the "fat" section to build it up to match the adapters. This isn't a done deal yet--nothing is glued. If I do indeed do it this way I'll glue the adapters in place and then soak the adapters with thin CA and then sand them to perfectly match the "fat" section.

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__________________
Never trust an atom. They make up everything.

4 out of 3 people struggle with math.

Chemically, alcohol IS a solution.

NAR# 94042
SAM# 0078

I believe that is Mercury Capsule.
The old capsule kit had adapters for that cone to all Estes tubes.

kj

Ah so! Thanks.

__________________
Never trust an atom. They make up everything.

4 out of 3 people struggle with math.

Chemically, alcohol IS a solution.

NAR# 94042
SAM# 0078

The report states that the motor case was glass wound.