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[WIP] German WWII rockets including never built absurdities

TiktaalikDreaming

By TiktaalikDreaming
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halowraith1

halowraith1

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so im guessing the a-11 and a-12 stages are a combination of estimates?

 

also will the ksp engine handle the 50 separate engines well? i havent been following development closely so i dont know if the stability issues have been fixed (especially for 64 bit)

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TiktaalikDreaming

TiktaalikDreaming

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Anything but estimates would be a lie.  But yeah, a combo from different sources, as some of the estimates don't seem to be sane.

And KSP seems to handle 50 engines OK (on an i5 2500K, 16G RAM, w/ nVidea 960)

KWumNgD.png

Edited by TiktaalikDreaming
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TiktaalikDreaming

TiktaalikDreaming

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Some work ongoing for parts between the A-11 and A-12 which are pulled purely from my imagination, and how to keep those tanks apart with those fairly large A-10 engines sitting there;

WLZXn4u.png

 

Also, I can't do albums at the moment, but for the A11 and A12 development, I'm incrementally adding images to http://imgur.com/a/8fjaD

And, last night I realised my comment "And KSP seems to handle 50 engines OK" only touches on the issues.  For the A-10, the thrust transform is actually eight transforms.  There's one per "gimbal" vane, plus a set of four to balance those out.  So, each of those 50 A-10 engines on the A-12 is, itself a set of 8 rocket exhausts (with accompanying exhaust, light, smoke effects).  So, if your PC can't handle 400 sets of KSP rocket exhausts, then you may experience trouble with the A-12.

That said, I noticed no slow down or frame rate issues.  I suspect rocket plumes are mostly handled by the GPU, while KSP's main load is CPU.  So if you have a GPU, you're probably fine.  I'll check if the A-12 makes my laptop explode later.  :-)

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TiktaalikDreaming

TiktaalikDreaming

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9 hours ago, halowraith1 said:

oh man... i just looked at the newest pics on imgur. that thing is huge even in stock ksp.... it's going to be massive in RSS...

The final width is 36m before scaling to Kerbal 64%, so in RSS it'll be 36m.I need to make it a bit shorter, and more ice-cream coneish yet.  For the A-12 stage, I started with the dimensions from Astronautix (Diameter: 11.00 m (36.00 ft). Span: 23.00 m (75.00 ft). Length: 33.00 m ) then expanded the base until it fit the 50 A-10 engines.  But, clearly, when I'm expanding the diameter from 11m to (an average of) 30m, the same volume requires a fair bit less length.
11m? The A-10 engine's outside diameter is just shy of 4m.  11m is mathematically impossible, even ignoring you want to balance the thrust (and add some symmetry to aid placing engines in VAB).  Those WWII plans were clearly expecting to use parts overlapping and clipping.

Just did the math.  To get the same volume, it needs to be 4.3m tall.  Not happening.  Artistic license time

Based on fuel masses, it should be about 4000 cubic m, and that leads to a larger size.  Still just 5.7m tall

Maybe if they ran the A-12 on non-liquid hydrogen???

Maybe I'll just shorten it till it looks just shy of stupid, calculate volume (I loves me my 3D Printer add on for Blender) give it that much juice and see if it lifts off.

 

5.7m tall by 36m wide looks fairly daft, but not as bad as I thought it would...

pPmaWLM.png

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8 minutes ago, halowraith1 said:

strange. most sources say that the final assembly of all 4 stages was to be 70 meters tall. drawing concur too including the one on the front page.

Yeah, I've been missing the engine lengths, just using the quoted lengths for the stage as fuel tank lengths.  But for the A-12, because the width is so absurdly larger than estimates, I'll base it on fuel volume.  But I'll re-do the calculation (the 5.7m was based on rough approx of densities), and double check the A-11 as well.  The A-10 is based on some fairly well structured diagrams, so I'm not going to mess with the shape/length/width of that, even if it's impossible.  So I'm not going to check.  :-)

But I'm sticking to my guns on the widths of the bases of the A-11 and A-12, as they're based on packing constraints for A-10 engines

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TiktaalikDreaming

TiktaalikDreaming

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1 hour ago, halowraith1 said:

wait so what's the reason for the redesign? surely the taller tank could hold the same amount of fuel?

It CAN.  It's just excessive.  And the taller it is, the flimsier it would be, and thus the more strengthening it'd be.  No-one builds rocket parts over-size for aesthetics.

I'll add in a fudge factor, as tank stages are larger than their internal volume.  But they're not 10 times larger than internal volume.

 

Just ran some numbers.  The A-4 fuel tank part's volume is 96.5% fuel.  AKA 3.5% is structure and empty space.  So that's a fairly good match.  The A-10 is only 50%, but that's not taking account of the big hole in it to fit half an A-9/4b.  AKA, there's a reason it seems a lot of empty space, that serves a purpose.  Albeit a dumb one.

If I assume they had big issues making large containment vessels, esp for the liquid oxygen, I can modify by the packing ratio of spheres (even if they'd be better of packing rounded cylinders) and go for a fuel to volume ratio a bit under 74%.  Maybe .74*.965, as they'll still need thrust structure and skin. .. um, insulation.  I'm just adding fudge factors to make me feel better at making it a bit longer now.  I'll make it about 8-10m, and just say they were crap at packing sub tankage areas in.

 

Edited by TiktaalikDreaming
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OK, revised the lengths.  The tank components are now shorter.  Doesn't look too odd on the A-11, but the A-12 is very wide.  I should do up some wing type things.  It doesn't seem to need them though.  Not with such a wide base of thrust vectored rocket.

PRueil7.png

 

That's me testing fairing decoupling, which still has issues (they collide and explode, 100% of the time).  No, I wasn't accelerating when testing.  :-)

I suspect the collider is overlapping at some point, so once it's not a part, but a different "ship", it immediately collides and explodes. 

But you can see most of the craft.  It's still huge.

 

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Now having a go at watching MechJeb try to land an A-10/A-4b on the Mun.  I got it pointing right for a deorbit burn, but now MJ seems to be having issues with no RCS and no reaction wheels.  I suspect crash and burn in a few minutes.  I might need to try this with some attitude control.

4 minutes ago, halowraith1 said:

will the a-11 have wings/stabilisers too? apparently it was intended as a satellite launcher (until it was weaponised, at least) so it might have launched without the a-12 stage.

Yep.  They'll be optional wings for the A-11 and A-12 I think.  neither seem to need them.

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18 hours ago, halowraith1 said:

niice... although it crashed when i tried to put the engines on first time...

will the a-11/a-12 fins be like a shroud? like on the a-10?

I'm not sure yet.  A lot of this has after the A-10 has been put together as "how does this actually fit together in 3D?".  So I really need to see if any of this works.

For the A-10, A-11, and A-12 there should be some sort of recovery parachutes.  Although I'm not sure they'll be super useful in non-RSS, as the craft has enough deltaV to get the first stage high enough it'd need re-entry shields and then chutes.

Wing shapes seem to be purely artistic license everywhere I look.  But could still be made to work I think.  But until I build them in blender, I really don't know.

3Sj2lvx.png

Edited by TiktaalikDreaming
pic of progress A-11 only just yet
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Sol Invictus

Sol Invictus

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@TiktaalikDreaming Detail in your work is amazing. In my opinion you should totally forget about stock game and focus all your efforts on making this mod fully compatible with RO/RSS/RP-0. Your work is most valuable for people who want their game to be as realistic as possible, and those people (myself included) wouldn't touch stock game with a 3.048 metres pole.

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5 hours ago, Sol Invictus said:

@TiktaalikDreaming Detail in your work is amazing. In my opinion you should totally forget about stock game and focus all your efforts on making this mod fully compatible with RO/RSS/RP-0. Your work is most valuable for people who want their game to be as realistic as possible, and those people (myself included) wouldn't touch stock game with a 3.048 metres pole.

Thanks for what I think is a vote of confidence.  :-)  I generally do my initial KSP stuff in stock, because I aim for stock config, and MM config to adjust for RF, RSS, and RO etc.  It's not really a good plan to make the base config anything but stock, because the only people without module manager (ie, people who have had the game for less than 10sec) are going to be those running very stock.  But basically, stock config first. 

That said, all the stock config comes with "rescaleFactor = 0.64" because I do all my modelling at full scale, with every intention of adding in the real world values later.  Sometimes, I get carried away making new parts instead of updating the MM configs for RF and RSS etc.  While this mod is a WIP, there will be parts that aren't complete, esp as far as RO config is concerned.  And it's likely to be a WIP for a while, because there's so many crazy ideas that (whether he was involved much or not is another question) have Wernher's name attached to them.  But, once I have some fins for the A-12 (that work in stock), I'll begin looking at the MM configs.  And maybe even textures.  :-)

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TiktaalikDreaming

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Today, I've been going back through the missing bits and pieces.

Decouplers.  The A-4->A-10 really needed a decoupler designed for the weird situation.  And I've made one, and in testing, it results in a LOT less exploding bits when separating.  Part of the problem was the stock decouplers are all fairly short, so the A-4 fins ended up buried in A-10 tank.  The new decoupler lifts up the A-4 a bit and results in a lot less pulling the wings off the flier.  I was getting a bit tired of all my test flights ending without any tail fins for the A-4 stage.

ranRyI6.png

Likewise, I built a new decoupler for the A-10 engine to sit on top of the A-11 tank.  This was less of an issue, as the A-10 to A-11 interface wasn't quite as nutty.  But, it still helps.

uvqbhIh.png

And, now that I could experience the joys of A-4 V-2 style fins, and their crazy small control surfaces, I thought it high time to add in the A-4b fin, which had decent sized control surfaces.  Now, I can almost pull out of a dive.  Before it approaches something you'd put a pilot in, it'll need a finless engine shroud for the A-4, and wheels.  Non of the stock wheels quite fit.

7ASGO71.png

 

 

EDIT:
I thought I'd already posted this, but I also have a giant wing thing for the A-12 stage.  So, the whole stack now looks like;

B4aYcyn.png

Edited by TiktaalikDreaming
Forgot to mention the A-12 Wing
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TiktaalikDreaming

TiktaalikDreaming

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2 hours ago, halowraith1 said:

Holy cow those fins are huge lol...

Will you be adding the a-6 ramjet soon as well?

I had the scoop half done ages back.  I'll scrounge around, see where I got up to.

=====================

Added a part, but getting the KSP jet engine to act like a simple ramjet will take some tweaking.  My first few tweaks never worked because I forgot to rename the intake transform as well, which doesn't help.

And (from memory, can't find the reference right now) the A-6 design included a slightly stretched fuel tank section for more ethanol mix, or jet fuel, can't remember which.

Anyway, went for a nice long cruise.

BZSy7CY.png

Edited by TiktaalikDreaming
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TiktaalikDreaming

TiktaalikDreaming

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Just a quick survey of opinion.

I've been tweaking the ramjet/flying stove pipe.  At realistic projections of it's useful velocity range, there's a fine balance between having it work, and exploding.  I'm very tempted to leave that in as a historically accurate "feature".  You *can* manage to find a middle ground between too fast-burn up and explode and the too slow-engine cuts out, nose dive into ground and explode.  It's just tricky.

So, do people prefer the challenge?  Or would you rather a more Kerbal-user-friendly experience?

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