Neil_W's half-baked design thread

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kuririn

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The last time I noticed (not recently) the ones that inexpensive calk came in were like Pillsbury canisters, rolled cardboard with a glossy or foil outer layer, and a metal end cap crimped on. So carefully scoring and stripping the outer layer in key areas to take glue wouldn't be so hard. Getting the metal end past the RSO might be harder.
Neil's link says HDPE, so you would need an HDPE glue, standard epoxies will not stick well to it.
 

jqavins

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Well yeah. What I meant to say, and neglected to type, is that one might be able to buy and dump a cheap calk tube to get the cheap tube. Or not, if things have changed.
 

mbeels

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The last time I noticed (not recently) the ones that inexpensive calk came in were like Pillsbury canisters, rolled cardboard with a glossy or foil outer layer, and a metal end cap crimped on.
Hmm, when I come across caulk tubes, they're usually superslick plastic, like cottage cheese or sour cream tubs.
I think both are out there now. The last tube of roofing tar I bought came in a Pillsbury canister-like tube, and the last tube of bathroom caulk came in a cottage-cheese tub-like tube.
 

DrewW

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I fixed something that was bothering me. In the previous design, the cut in the nose cone was too close to the base; that is, it was closer than all the body tube cuts. Here's a fix for that:
View attachment 408168

As a bonus, the purple nose cone now fits normally into the short blue BT segment, and the break in the rocket is just above the green segment. This completely eliminates the difficult job of getting the nose cone shoulder mounted at an odd angle, and makes the joint between the ejectable nose and the airframe pretty easy. And it looks better (obviously we wouldn't use these colors).
Okay I’m a year late to the party on this but just spent the last three days binging on the 1400+ posts in this thread. @neil_w if it hasn’t been built yet and christened I’d suggest “Shear Plane”.

Great designs here, I hope to design something half as good someday.
 

neil_w

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Okay I’m a year late to the party on this but just spent the last three days binging on the 1400+ posts in this thread. @neil_w if it hasn’t been built yet and christened I’d suggest “Shear Plane”.

Great designs here, I hope to design something half as good someday.
Welcome to the party, such as it is. :)

Shear Plane is pretty good for that one, I might just use it (although I have no plans to build it at the moment).
 

DrewW

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Welcome to the party, such as it is. :)

Shear Plane is pretty good for that one, I might just use it (although I have no plans to build it at the moment).
Very curious, what's at the top of the build pile?

Also, I feel like an opportunity was missed for a Goonie Star Voyager along the way. Just one man's opinion.
 

neil_w

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Very curious, what's at the top of the build pile?
That is classified.

Which is another way of saying "I haven't decided yet". :) Right now I'm still not quite finished with my maybe-to-be-modified Estes Mini A Heli.

In the meantime, this could be fun with a good paint scheme:
1614307203018.png

As with most of my designs, not destined to set any altitude records. :)

My original thought on this was simpler:
1614307318773.png

The pods make it more sci-fi. Not sure which is better.
 

mbeels

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I think I like the pods, but a lot would depend on the paint scheme. The pod version would work well with something featuring a cockpit windshield, while the podless one could look good with a more abstract design.
 

DrewW

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That is classified.

Which is another way of saying "I haven't decided yet". :) Right now I'm still not quite finished with my maybe-to-be-modified Estes Mini A Heli.

In the meantime, this could be fun with a good paint scheme:
View attachment 452396
As with most of my designs, not destined to set any altitude records. :)

My original thought on this was simpler:
View attachment 452397
The pods make it more sci-fi. Not sure which is better.
I like the pods, maybe the 5 finned design would look great with them?
 

jqavins

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I like the pods, maybe the 5 finned design would look great with them?
Ding ding ding diiing! Beat me to it.

You could even go up to eight pylons and pods, put candles in the pods and a ninth one in the tip for a few days every December.

Any thoughts on the recovery? Simple nose blow would be fine, but it feels like it wants some sort of sci-fi separation system.
 

neil_w

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Ding ding ding diiing! Beat me to it.
1614345114487.png

I'm not sure I'm in love with the exact pod design, but don't know where to go with it at the moment. As drawn, it would be absolute hell to build... although now that I think about it, those pods might be well-suited to 3D printing (then the appropriate slots for fins and ring could be built-in). The main body transition would also be a serious challenge, but who's counting...

Perhaps the tail cones in the pods aren't needed?
1614345462254.png

What the heck is that thing anyway? Weird alien spacecraft? Some sort of space missile?

Any thoughts on the recovery? Simple nose blow would be fine, but it feels like it wants some sort of sci-fi separation system.
My design thoughts usually do not extend to weird recovery schemes; I'm usually thinking plain old nose-blow. This one is build around the good old reliable Estes PNC-55BB, which I've used in two designs so far. BT55 core is sufficient for easy parachute stuffing.

Open to weird suggestions, though. :)
 

jqavins

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With the tail cones left off of the pods, it will certainly sit better on the shelf. (Well, sure, it's stable on three or more points, but those points would wear horribly.)

For ease of construction, the the pods don't really have to extend inside the ring. If you move them out so that the inner line of the pod cone hits the top edge of the ring then remove everything below that on the pod and inward of the ring outer edge... Let me sketch that, it'll be easier than trying to explain verbally (a thousand words and all that).

(A few minutes later) Here's a side view cross section. Looking at it, I realize that the removal of material form the pod cone is what a roofing carpenter would call a bird's mouth.
1614348325323.png
 
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Sooner Boomer

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That is classified.

Which is another way of saying "I haven't decided yet". :) Right now I'm still not quite finished with my maybe-to-be-modified Estes Mini A Heli.

In the meantime, this could be fun with a good paint scheme:
View attachment 452396
As with most of my designs, not destined to set any altitude records. :)

My original thought on this was simpler:
View attachment 452397
The pods make it more sci-fi. Not sure which is better.
Where/how does the launch lug(s) attach? Do you put them on on angled standoffs so that they are vertical, or do you simply glue them onto the side and launch it at a canted angle? I've got a similar design based on a Hobby Lobby Christmas tree.
 

neil_w

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Where/how does the launch lug(s) attach? Do you put them on on angled standoffs so that they are vertical, or do you simply glue them onto the side and launch it at a canted angle? I've got a similar design based on a Hobby Lobby Christmas tree.
For this one I figure the lug would need to go through the cone and emerge somewhere or another.
 

neil_w

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For ease of construction, the the pods don't really have to extend inside the ring. If you move them out so that the inner line of the pod cone hits the top edge of the ring then remove everything below that on the pod and inward of the ring outer edge... Let me sketch that, it'll be easier than trying to explain verbally (a thousand words and all that).

(A few minutes later) Here's a side view cross section. Looking at it, I realize that the removal of material form the pod cone is what a roofing carpenter would call a bird's mouth.
That's a very good idea. Minimal affect on appearance.
1614450582808.png

BTW as shown, the rocket as designed is about 18" high, and the ring is 6.25" in diameter. The base of the cone is 3.5" in diameter. Could be scaled up as desired, but the challenge of creating the body cone scales up with the size.

This needs a good paint job, but I don't have any great inspiration at the moment. I'm definitely thinking alien spacecraft (and therefore some weirdness), an a cockpit somewhere along the cone.
 

mbeels

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Looking at it, I realize that the removal of material form the pod cone is what a roofing carpenter would call a bird's mouth.
Never knew that is what it is called. I assumed it was some special kind of rabbet, but I like the name bird's mouth.

The base of the cone is 3.5" in diameter. Could be scaled up as desired, but the challenge of creating the body cone scales up with the size.
For scaling up, all it would take is the right size conical nose cone. Looks like a fun rocket. It's almost saucer-esque.
 

jqavins

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This needs a good paint job, but I don't have any great inspiration at the moment. I'm definitely thinking alien spacecraft (and therefore some weirdness), an a cockpit somewhere along the cone.
Or (this is less than half serious) you could go with a three or four color spiral, like a tapering, dimented barber pole.
 

afadeev

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BTW as shown, the rocket as designed is about 18" high, and the ring is 6.25" in diameter. The base of the cone is 3.5" in diameter. Could be scaled up as desired, but the challenge of creating the body cone scales up with the size.
This looks cool, but how would you actually construct the conical airframe?
Cutting out a triangle out of a 6.25" body tube would be one way, but the end result will likely be less than a perfect looking cone (seam glue section will stand out).
Getting a custom made (plastic? fiberglass?) full-length nose cone, with custom shoulder assembly, would look better, but would be more expensive and harder to source.

So, what's the plan?

a
 

jqavins

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He already mentioned a central BT-55 and a PNC55BB on top. (Plastic Nose Cone, fits BT-55, and BB must indicate the conical shape I guess.) Neil is known to do a lot with cardstock shrouds. So we may assume that there is a 3.5 inch centering ring at the base, and some numner of progressively smaller rings up the length (three, four?) and a cardstock skin.
 

neil_w

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He already mentioned a central BT-55 and a PNC55BB on top. (Plastic Nose Cone, fits BT-55, and BB must indicate the conical shape I guess.) Neil is known to do a lot with cardstock shrouds. So we may assume that there is a 3.5 inch centering ring at the base, and some numner of progressively smaller rings up the length (three, four?) and a cardstock skin.
Yeah, that. :)

I suspect a single giant shroud would be impractical, so let's say 2-3 pieces.

Not for the faint of heart. :)
 

jqavins

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With great respect for your infinitely greater experience with shroud work (your lots relative to my zero, so infinitely) had I to guess I'd have thought that managing a single large piece, hard as that might be, wouldn't be as hard as lining and matching up multiple ones. But you're the expert.
 

kuririn

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Same method used in the TLP Pershing I.
0227211137[1].jpg

BNC-60 nose cone, BT-60 tube, three shroud segments nesting into each other supported by three centering rings along the length.
 

neil_w

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With great respect for your infinitely greater experience with shroud work (your lots relative to my zero, so infinitely) had I to guess I'd have thought that managing a single large piece, hard as that might be, wouldn't be as hard as lining and matching up multiple ones. But you're the expert.
Either way it would be hard. I do recall in making the shroud for the APRO Lander II, the big one was a pain in the butt, and the final product was very far from perfect.

Here's the shroud for this one; I measure it as requiring a 10.5" x 10.75" sheet (which means starting something like 11x17).
1614471502249.png

Cut into two pieces, it could easily be done with 8 1/2 x 11 cardstock. On the APRO, I used stringers (of sorts) to support the transition, would definitely want to do that again here.

Not clear that this design is worth the (considerable) effort, although there's still fiddling to be done to make it more compelling.
 

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Why make it when you can buy it? I've got several "cones" that are sold by Hobby Lobby as Christmas trees. This one has a base diameter of about 4 - 4 1/4" and 16 - 16 1/2 inches tall.

cone.jpg


Christmas decoration, so Hobby Lobby should have them on sale next week or so...
 

neil_w

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I was still thinking about this. BNC-5S. Cut off the shoulder, sand in the bird's mouth.
... and I will definitely do it that way, if those cones stay in the design, and if I ever actually build it. Both of those are uncertain at best. Would need a good paint scheme before I even consider a build.

Oh, I update the fin shape, like it a bit better now.
1614799872263.png

Seems like I just can't quit curved fins.
 

jqavins

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I like the curve. I might curve them even more, and bring them higher. The outward end curving all the way to horizontal (when the rocket is standing up) and the inboard end curving up to tangency with the cone. Something like below, where the black is the outline of the pylon and the green is a partial outline of a cone cross section. There are many parameters that could be adjusted to taste, including the type of curve. (That one is a hyperbola, rotated to make the bottom horizontal. An exponential would also work well, I think. And there are myriad other possibilities with other math or, say, French curves.)
1614808345214.png
 
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