ARCASes for me

I like ARCAS rockets (go figure)

About to build one "standard" and one HV model, from fiberglass/wood/cardboard scraps I have around. I cannot find good scale data for either I am also not that concerned about the finer details, but would like to get the length/diameter ratio correct and fin shape correct, as well as an authentic looking paint job.

Wikipedia has L/D for one of them but does not indicate if that is tubing length, or full length including the nose. I assume the latter but anyone know? Know if the HV is the same ratio?

Do HV and "standard" have the same fin shapes?

HVArcas said:

Wikipedia has L/D for one of them but does not indicate if that is tubing length, or full length including the nose. I assume the latter but anyone know? Know if the HV is the same ratio?

Do HV and "standard" have the same fin shapes?

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No, they do not.

Dave F.

Oh that is fantastic, thanks a ton!

I suppose that ties in to my other question, what the heck does "HV" truly mean historically. Most places that use that moniker seem to be referencing the Aerotech or MaDCow kit, heck I half thought it was to avoid trademark on the Super Arcas or Robin?

I have seen "HV" refer to "high-velocity".

I built a SLS 1/2 scale ARCAS as one of my first high power capable rockets. Very nice detailed model, balsa tail cone, balsa nose cone and bass wood fins with nice detail with the "mounting bolt" found on the real sounding rocket.

I did research and chose the white/red paint.

https://www.rocketryforum.com/threads/scale-atlantic-research-arcas-gallery.16562/

~John

Ez2cDave said:

I have seen "HV" refer to "high-velocity".

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Sorry, that part I knew, what I was trying to say was I never see specs or comparisons between HV vs standard, only standard vs robin/super, and I was speculating that modelers made up HV to avoid copyright or something.But maybe HV was a real thing from Atlantic Research Corp, I have no idea.

HVArcas said:

But maybe HV was a real thing from Atlantic Research Corp...

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It certainly was, but I believe only as the second stage of various two-stage "Boosted Arcas" configurations. See https://en.wikipedia.org/wiki/Boosted_Arcas and the links from there.

mikec said:

It certainly was, but I believe only as the second stage of various two-stage "Boosted Arcas" configurations. See https://en.wikipedia.org/wiki/Boosted_Arcas and the links from there.

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The Boosted ARCAS ( several versions ) and the Sparrow-ARCAS . . .

Dave F.

Scale data for the ARCAS is redibly available and has been since at least 1969.
https://www.ninfinger.org/rockets/ModelRocketry/Model_Rocketry_v01n06_04-69.pdf

It is a very simple rocket and so there are not a lot of "details" unless you want to get into modeling the various payload options and nose cones.

Data for the boosted and HV versions is harder to find but enough for a decent model is available.

Visually the only difference between a stanadard ARCAS and the HV version is the fins. The ARCAS has a visable tailcone and fins that wrap around it. The HV has a fin can that hides the tail cone and the fins are larger. The span is the same, but the root edge for the HV is 9.85" vs 6.8 for the standard.

A lot of good info - thanks all!!

The Boosted ARCAS . . .

https://www.jcrocket.com/boosted-arcas.shtml

Get THIS, while you still can !

PART 1: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19700021281.pdf

PART 2: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19700020646.pdf

Dave F.

dmo said:

Scale data for the ARCAS is redibly available and has been since at least 1969.

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Only when you are looking in the right place!

Super glad I asked, this turned in to quite an excellent repository of ARCAS info.

HVArcas said:

Only when you are looking in the right place!

Super glad I asked, this turned in to quite an excellent repository of ARCAS info.

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Depending on the prototype, the "ARCAS Bear" logo is also needed data.

Dave F.