Starship Avalon: build thread

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Balsa bending experiment #2: two pieces of 1/16 balsa, wet with windex then soaked in hot water for 90 minutes. Titebond II between the balsa.
ImageUploadedByRocketry Forum1476473097.234716.jpg

I do not really know if the soaking was sufficient. We'll see come Monday.
 
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Ah, Jimmy Buffet, the official soundtrack of vacations everywhere.

Well, come this Monday everything is indeed alright. The tape was still holding the balsa tight and oh forget it let's just get back to business here.

Here are the results:
ImageUploadedByRocketry Forum1476713515.136974.jpg

Observations:
1) Both pieces held shape perfectly. I am pleasantly surprised.
2) At the very ends they're not quite perfect, due to (a) the tape not being able to hold the edges 100% flush against the form, and (b) Indentations from the clamps. That means that when I make the real parts, I'll make them a little extra long and then trim afterwards.
3) The two-ply laminated piece is ROCK HARD. I mean that thing not gonna flutter, at least not at the velocities this rocket would fly at.

Therefore I am declaring victory. When I go forward with this build, I'll use the two-ply method and these pieces should be great.
 
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Awesome. Should be fairly easy to make a twisty balsa overwrap for an LP tube using this method.

No ideas immediately come to mind, maybe something in the steampunk range.
 
Cool...onward and upward!

Yeah, I'm running out of excuses for not building this. I think I'm gonna fabricate my twisties while figuring out the rest.

That crazy motor mount is still vexing me; I should probably ditch it but I'm going to try a while longer before I give up. It actually won't look great while loaded with an engine (since the engine will be exposed) but on the shelf it'll look great. Anyway, there's no way to put a hook there without it being really ugly, and I think friction fit would put too much stress on it during insertion or removal. I'm actually thinking about 3D printing the whole assembly that hangs out the back, and making it removable. Then I'd put an engine block in the back, and I'd be good to go. Executing that plan is not trivial, though. I'm open to suggestions here.

Also, although I like the decor so far, it feels incomplete for a starship. Open to suggestions there as well. In the original from the movie, the helical parts appear to be passenger compartments, so they're lined with windows. I don't know if that'll still look right on my version, and I can't preview it in OR. The fat part at the front also needs something. I'm not very good at creating those sorts of details. Finally, if there should be a third color here for accent, I'm not sure what it should be or where it should go.

Awesome. Should be fairly easy to make a twisty balsa overwrap for an LP tube using this method.

With the 1/16" balsa I'm using (again, this is a pretty hard piece), it'd be unlikely to wrap around an LP tube (even with a coupler inside) without crushing it. A lighter piece might have a shot, or 1/32" balsa would probably be no problem. I had intended, based on what I read online, to do a 3-ply layup with 1/32" balsa, but I couldn't easily find 1/32" balsa around here so I just went with two layers of the 1/16".
 
After I get done making my 2 gallons of applesauce, I'm going to turn the nose cone for my lil Bo Bo boiler plate version and hopefully get it assembled this evening. I just want to see if it'll act stable with those fins. I'll post a pic if I get done with it. The soccer field down the street is good for A & B flights. Maybe a test flight then?
 
Cool.

It has occurred to me that, given the thick (1/8") profile off my helixes, my rocket will almost certainly spin; I wish I could think of a way to avoid that, but I can't. Yours may not, given that you used much thinner materials.

Also, my design actually has quite a bit of fin area (even excluding the helixes and rings), so I'm really not worried about stability *assuming* I get it all built square (no mean feat in this case). The cross section of your pylons is not totally clear to me, so I can't tell if they'll be contributing to stability (also your helixes look pretty spindly). In any case, it will be interesting, look forward to your reports!
 
Very cool. Very very cool.

I would think that some degree of spin would be unavoidable. However that actually would add to it`s appeal
 
Very cool. Very very cool.

I would think that some degree of spin would be unavoidable. However that actually would add to it`s appeal

Seems if the fore surface of each pylon were intentionally angled to oppose the spin induced by the front of the curved section, a balance could be obtained.

Or sand them the other way and really drill the sky :)
 
Seems if the fore surface of each pylon were intentionally angled to oppose the spin induced by the front of the curved section, a balance could be obtained.

Calculating the pylon cant to equalize the rotational forces is waaaaaaaay beyond my pay grade. I'll just let it spin.

Then again, I suppose I could just take a swag at it and see what happens. Probably won't bother, but hmm.
 
Ah, I see. Yeah, could do that (probably couldn't hurt) but that shouldn't be nearly enough to offset the effect of the helixes.

Actually, now that I think about it, I could kinda sorta calculate the spin force of the helixes. Hmm, must think about this further. Still not sure if I actually want to try to despin it, but it's worth some consideration.

Really, this is a possible argument for making the helixes thinner, to reduce the drag and spin force.
 
1st thing I'd do is, fly it like it is, no tailoring. Go nekkid! See how much (if any) spin you get. Then consider the added resistance factor if you decide to despin it. Adding more resistance is probably not a good thing. I'm sure you'd like to keep the fin can attached to the rocket while it's flying. Rounding your pylons is prolly your best approach for the least resistance. The type of blades you are making for the helix prolly will spin, but don't count on that. My Gyro Dragon won bets on that no-spin issue. It might not. That's why you wait to paint one like this.
 
That's a good idea, *if* I can figure out how to paint it after assembly. This is really looking like one that needs to be painted as it's built (lots of nooks and crannies here), although I could certainly hold off on post-assembly finishing touches until after it proves its flight-worthiness. I guess I'll see how much I can plan to do afterwards. Could even maiden it without the rings, which are a big part of the paint sequence. Will consider.
 
Here's my crazy idea, sounded better in my head than it looks on the screen, but I dunno, maybe. I was trying to think of a way to provide a balanced counter spin force, and this is what came from that. As shown, it would *not* actually solve the original goal, but whatever.
avalon_counter.png

It's a bit hard to appreciate this from static images; looks more interesting if I spin it in OR (likewise, it would probably look better in person when you could move around it.)

It also starts to look less like the original movie version (not really a concern anymore), and more like a push-mower blade. I can't decide if this is an improvement or not.
 
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Actually that's starting to look a bit too busy, doesn't seem to flow as well as before...IMO

The only way to know for sure is to build it. Then if you really, really want to tackle the rotation, you can use an Apogee-style wind tunnel(or out the passenger window of a car) with the rocket mounted on a spinnable dowel to test the rotation and tweak if need be.
 
I agree. My idea about adding some counter spin was to bevel the lead pylon. Say, the rocket wants to spin counter clockwise, you'd want to bevel the pylon on the left side to counter that spin. Still, you have that much more wind resistance to deal with. FWIW, let it spin. There's no harm in that.
 
And I agree as well, too busy. And I'm officially abandoning all thoughts of spin control, the model will do what it wants.

One thing I'm gonna keep from that version is the taper of the helixes. Previously they were rectangular pieces (as approximated in OR). Now they're narrower at the ends than in the middle; I think it looks a bit more graceful.

Design is almost final. One final decision: keep the rings or drop them? Each approach has its charms.
avalon_rings_or_not.png

BTW, the individual segments of the helixes sort of look like Andes mints.
 
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I like the rings. Especially to help make the color pop a little more.

Yup, me too, now that I've been able to stare at them side by side for a while.

I'm calling the design complete, other then the decor. Now will focus on structural questions, mainly engine mouth and whether 3/32" balsa is sufficient for the fins or if I should go to 1/8".

This will transition to a build thread soon (I assume that's preferable to starting a new one?)
 
Rut Row.....

You done it now.

View attachment 303629

:lol:

Is that a picture of yours crying because it never got a finished paintjob? :neener:

Anyway, I haven't forgotten about it (and I still have all that nice laser-cut balsa waiting for me). Right now the transitions are holding me back a bit; I've made a few and they came out "OK", but I'm not feeling confident with the whole thing yet. I'll probably be working on that in parallel with this, ensuring that neither one will ever get done... :wink:
 
It appears you had a run-in with Angry Launch Lug. That little guy has been dormant for over a year now, and you woke him up. Not to worry though. He didn't come here to start any trouble. He's quite the the rocketeers assistant when he wants to be. But I think he wants to keep an eye on you now. He will rant when he thinks you did something foolish or screwed something up without thinking.

BTW, I have no control over him. He accesses my account at will.
 
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