The posibility of a full-scale ARCAS....

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Well-Known Member
May 10, 2011
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With 11 60" by 4.217" OD tubes left over from my dad's L2 airframe, the idea has arisn that it is possible that I could make a full-scale ARCAS. Assuming each wrap of glass gives you .05" on your airframe diameter (I am just going by what Sandman told me a while ago when I was contimplating a full-scale ASP), I would need 6 wraps of cloth to get the 4.5" airframe diameter I would need. That would make it very heavy (could anyone tell me HOW heavy, please?). I could always use 3/4 OZ glass for some of it to save weight if neccesary. I currently have no idea on how much this thing would weigh, and it might just go to the same place the 8" sono rocket, PVC pipe rocket, and all that went (the trashcan). But its an interesting thought, and I have always wanted a full-scale ARCAS (or HV arcas, for that reason...). I have not looked at the scale data yet, so I dont have any particulars. Especially after seeing the price on the only full-scale kit I know of (Performance rocketry), it looks pretty nice....The airframe would be VERY thick (about 1/4" or more....). So I dont know how possible this is. I just thought I would post the idea, just to get some opinions.
Go for a full-scale Super Loki Dart instead; you won't have to wrap endless amounts of glass around it to get dimensions right, which will bring the weight to something on the order of 30 pounds...
Thats the one with the tiny fins, isnt it? I dont want to do it if its THAT one... How do ya make it stable? Gyroscopes?

I think that this would make a very fun project for you and your dad. What better way to take advantage of a new L2 cert, right? I would not recommend going with several wraps of glass - it would add a LOT of weight. I would go with making it something like 99% scale, or whatever the scale would be using those tubes you have. I would think that one, maybe two wraps of glass should do it for reinforcement. And to get that baby off the ground, put a 54mm mount in it. Go with 1/4" ply fins with a layer of glass on them...

I love the Arcas - I hope this turns out good for you! Just don't try to rush it, and have fun while you do it!

do what jetra said. Imagine how built up the nosecone will have to be to fit the nosecone. It will be much simpler to do a little math than all the fiberglassing work.

I saw one of these once, it was a scratch and flew on 4 J330s. Man did that thing do
%95 scale, by the looks o' it. It would need a tube about 69.75" long, so it would have about 17.5 (give or take) of nosecone. It might take the P1500-75 to lift it! (thats what the "NAR designation" says in Rockets Of teh World). Well, maybe a J350, but still... I actually dont think it NEEDS glass that badly... I sure cant make one of those thing bend, even if I push wicked hard on it. They aint flimsy, these things! I think Ill look to see if there are any other nice rockets this size that I could make full-scales or half-scales of.
Didnt see your reply before I posted...

Its not the math thats the problem (I have no problem with that.), just that I would have liked a full-scale. Oh well. Cant have it all. Ill let ya'll know what I decide. Gotta go play with Puppy now... Bye!
Pfft...don't worry about that measly 5% off...any rocket that big is fun. :D :D

Please wait until after your dad has finished his level two project before you start this one! Reason being, this will allow you to fully plan out this project before you start, and you'll learn some/most/many of the techniques you'll need to do this scale of project. Have fun with your dad as you work on the L2 project!

Actually, it makes more sense to me to make 2 of everything at the same time. Two nosecones, 2 glassed tubes, 2 chutes, all that. Just makes it that much easier. I dont think my dad will start building his L2 for another few months, so I might jump the gun a bit and get the designing done now and build at teh same time he does. Or maybe Ill wait. It remains to be seen.:D
Ok, I see your point. I'll actually be doing the same thing soon, when I start my 6" Big Daddies and my 8" QT rocket. That'll equal out to three foam nosecones, two glassed body tubes, and expanding foam all over the place... LOL! I'm just trying to help ya, Neil! Don't jump the gun on your dad's L2 project though, the rules say that the person that certs need to build the entire rocket, I believe. So, I would think that you could do the chutes, and glass the Arcas' tubes, then maybe some weekend work with your dad on making the nose cones! That would be fun, wouldn't it? :D :D

Have fun!

I read that rule.... And, he can convienently save shipping on custom chutes, pre-glassed tubes, and nosecones by ordering from MMHPR! Should I make him fill out an order form:D :p ?

I wasnt talkin about jumping the gun on my DADS project, just jumping the gun on your suggestion that I wait till he certs to start my rocket.

Big daddieS?? as in TWO? Jeez.... Well, after so many Dueces, I s'pose you start seeing everything double, dontcha?:D ;) but TWO.... Well, I suppose I could make 10 60" long 4.271" diameter rockets, but wheres the fun in that? I suppose it would be nice to have a backup, in case one CATOs or something....

The things you can do when you have a real job...:rolleyes:
Well, heres an alternative to the ARCAS. The ARCAS would need 2 tubes, the 1 tube isnt quite long enough. So I designd another project that has a 54MM motor mount (But I dont plan on using it for a while), and would fly motors mostly within the H242T-I366 range, but then, of course, it has the capability of the J350 and J420, and even the smaller 54MM motors later on. I would like to put a tailcone on it, and I bet I could make one out of foam and glass. So, tell me what you think of the simulations. thanks guys! -Neil

I'm not saying the Arcas is a bad choice. No way, no how. Go ahead and build it! Just a suggestion, before you start building it, make yourself a plan and a list of things you want to accomplish on this rocket. Something like this:

On this rocket, I want to expand my use of fiberglass and epoxy, along with using all-thread rods and expanding foam for reinforcement.

Then make yourself a timeline/schedule of stuff you want to do each day. Say on day one you want to cut the rings and the fins out of ply. Day two, you want to prepare the tubes for glassing... etc., etc. You get the idea. This probably isn't a bad idea for any kind of HPR project... ;)

Im not saying you did. I am just saying that this is another possible choice. It sure seems easier than teh ARCAS. I would have to make a coupler and a lot of other stuff. Plus I like the way this one looks:D I am still a ways from deciding which one (or, heck, both. I do have 11 extra tubes...). Maybe I will build both.... Proabably not at the same time, but maybe this summer.
Quote: Well, after so many Dueces, I s'pose you start seeing everything double, dontcha?


Now that's funny! Good joke!

:D :p ;) :) :D

Quote: Then make yourself a timeline/schedule of stuff you want to do each day. Say on day one you want to cut the rings and the fins out of ply. Day two, you want to prepare the tubes for glassing... etc., etc. You get the idea. This probably isn't a bad idea for any kind of HPR project...


Good idea! I wish I thought of that before. :rolleyes:


I like the ARCAS idea but go with whatever you want. I have personally always liked the ARCAS. Whatever you do, make sure you get all the parts and resources first. Get your dad to help (not saying you couldn't do this on your own), it would be a fun project. I would like to build BIG rockets like this sometime but like yo said:

"It must be nice to have a REAL job."

I wish I had more money coming in than goes out. In other words, I have ~$18 left to spend and that will go toward paint for my BSD 4 inch Horizon and a H165R to fly it on. After that money is gone, I have to wait untill grass cutting season starts again. Oh, well.
How about I sell you a exact Scale Nosecone and the right diameter paper tubing for you to make your own low cost 4.5 Inch Full Scale Arcas ?

Here is the deal
1 Fiberglass 4.5" Scaled Arcas Nosecone
6 ft of Kraft Glasine Airframe Tubing (1 4ft and 1 2ft)

I do not have couplers for this tubing but if you wrapped a couple of layers (1 or 2) around a LOC or PML 4" Airframe it would be perfect.

You could build either a HV Arcas or the Boattail Arcas
Both diagrams are in Peter Always

Let me Know
OK. Now that this is all settled, I need to know how big the HV ARCAS fins are, 100% scale. Does anyone know? ROTW doesent tell me much...:mad: :rolleyes:

I have some HV Arcas full-scale data that came with my Aerotech kit. I'll dig it up today and give you the info, ok?

Great! Thanks. now I wish I bought the AT ARCAS when I had the chance....:( good thing you saved the data... My email is "[email protected]" ([email protected] Im not sure if that link will work, but its worth a shot. Thanks again!