[WIP] Real Engine Models

[Agathorn]

Hey all,

This work spawned out of my time spent playing with the Realism Overhaul mod and the associated collected mods that go with it. While the aim of all those mods is to make KSP as real as possible, they are working with whatever part models they can, and just changing stats. While I certainly applaud the effort, I wondered if maybe we could do better.

So this is my attempt to start providing models for real world engines. I will be making them as close to the real thing as possible, within reason. They will NOT have the "engine plate" on the top of the engines like most KSP engines do, but will instead mimic the real world counterpart and at most have a thrust plate or thrust frame.

I've only just started so there isn't much to see yet. I'm posting one early WIP of an unfinished RS27a, untextured.

I'm doing this in my very limited free time so I make no promises on progress, but if you want to join the ride please do. Constructive criticism and feedback are welcomed at any time.

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Edited January 19, 2014 by Agathorn

[AbeS]

Really nice! We will finally get engines without those ugly plates! Keep up the good work!

[Agathorn]

Really nice! We will finally get engines without those ugly plates! Keep up the good work!

Thanks!

I edited the first post now that I figured out how to embed the Imgur album. No more fugly thumbnail.

[ferram4]

A very nice start, but some criticisms from what I can see:

The structural hoops on the nozzle don't appear to be evenly spaced, it's particularly notable between the 1 and 2 compared to 2 and 3 (counting from the bottom and not counting the lip at the end); check the distance between them and even it out.

Around hoop 5 it looks like the engine bell is curved the wrong way; the line between hoops 4 and 6 is probably straight, but since the nozzle it broken up visually by the hoops you need the angle to change, even if just a little to make it look right.

It also looks like the hoops are inconsistent in their thicknesses; it looks off.

It's a very good start, keep at it! It just looks like it needs a ruler put next to a lot of the elements to make them consistent.

[Agathorn]

Are the hoops supposed to be evenly spaced? I was pretty much just going from the pictures I had for reference and they weren't really consistent. Spacing was different and sizing was all over the chart.

EDIT: On the curve, I assume you mean the nozzle. I used a schematic of a typical Bell curved nozzle, and then tweaked it to match the RS27A. It is pretty darned close to the references I have, with the exception of it being low poly so the curve isn't quite as smooth as it should be. I can make it better but the poly count goes through the room to do it unfortunately

Edited January 19, 2014 by Agathorn

[ferram4]

The pictures I come up with when searching for "RS-27A" look like the hoops are evenly spaced and like they have the same thicknesses. Most engines that have those on them seem to have even spacing between the hoops, so I don't see why this one would be any different.

[Agathorn]

The pictures I come up with when searching for "RS-27A" look like the hoops are evenly spaced and like they have the same thicknesses. Most engines that have those on them seem to have even spacing between the hoops, so I don't see why this one would be any different.

Ok i'll see about tweaking it.

[NathanKell]

Agathorn: very nice! So glad you're doing these.

My eyes aren't as good as ferram--I only noticed int optical-illusion-inward-tuck, not the bands issue; but for the former even if you pop it out only a few mm that should be sufficient to destroy the illusion (and I rather doubt a Rao nozzle has any straight stretch anyway; might be an issue in the illustration?)

[Agathorn]

Agathorn: very nice! So glad you're doing these.

My eyes aren't as good as ferram--I only noticed int optical-illusion-inward-tuck, not the bands issue; but for the former even if you pop it out only a few mm that should be sufficient to destroy the illusion (and I rather doubt a Rao nozzle has any straight stretch anyway; might be an issue in the illustration?)

The illustration I used had a very short section at the very bottom that was pretty straight. Not much, maybe the bottom 5% or so. I can tweak the profile a bit, but unfortunately I can't make major changes without undoing a lot of work.

Any chance you guys could identify the section of the profile that is bothering you?

[ferram4]

Alright, looking from the bottom going up, and only considering the shape of the nozzle, ignoring the hoops:

From the lip at the end of the nozzle to 3rd hoop from the bottom it looks good; a nice curved shape. From the 3rd hoop to the 7th hoop it looks like the engine nozzle it built out of one single cone with straight sides. From hoop 7 up looks like another. There looks like there might be a change in the angle at hoop 9, but I'm not sure without a protractor handy. The problem is that the sudden change in angle at hoop 7 makes heavily accents the straight lines above and below it.

Don't take any of this the wrong way, it's a great start.

[Agathorn]

Alright, looking from the bottom going up, and only considering the shape of the nozzle, ignoring the hoops:

From the lip at the end of the nozzle to 3rd hoop from the bottom it looks good; a nice curved shape. From the 3rd hoop to the 7th hoop it looks like the engine nozzle it built out of one single cone with straight sides. From hoop 7 up looks like another. There looks like there might be a change in the angle at hoop 9, but I'm not sure without a protractor handy. The problem is that the sudden change in angle at hoop 7 makes heavily accents the straight lines above and below it.

Don't take any of this the wrong way, it's a great start.

Ok I think I see what you are talking about. I assure you it isn't a straight line, but I think there is some small jump going on there. I'll see if I can smooth it out without adding too many more faces.

[Talisar]

I want to lead off with saying that I think the model looks great! I think see what Ferram and NathanKell are talking about, so I made a diagram:

It's nothing too serious, and a lot of the illusion could be due to the render as well. I love the model, keep up the great work!

[specs]

The pictures I come up with when searching for "RS-27A" look like the hoops are evenly spaced and like they have the same thicknesses. Most engines that have those on them seem to have even spacing between the hoops, so I don't see why this one would be any different.

Except, it is:

Regardless, good on ya OP.

[123nick]

doesent kosmos have something about engines without thrust plates?

[Agathorn]

I've cleaned up the profile a lot, and matched my rings to Specs' second picture there. At least as best I can. I've matched position, but the individual ring sizes will still be a bit inconsistent without me ripping the model apart and redoing the whole nozzle. I can do that but I think with the better profile and positioning on the rings, it won't be such an issue.

In redoing these though I noticed a major problem with the throat so i'm trying to rework that now.

[Agathorn]

Album in OP updated with WIP2 on the RS37A. I think the profile looks a lot better now.

Yes the armature is in the wrong spot now. I forgot to re-position it after changing things

[Agathorn]

I'm still curious about all the bits above the combustion chamber. In every picture I can find of the engine on an actual rocket, not a test stand, none of that is visible.

[specs]

From what I'm seeing, it looks as if it has three strut-bars in a triangle formation, and if this is the drawing you're referencing:

Than I'd say it's spot on.

On top of that, it seems like the three reinforcing struts that make up the triangular attachment point, come down to the center of some (hopefully strong) equipment atop the inlet plenum. As seen here:

and here:

There's also the "gimbal", which looks like a simple pneumatic, or hydraulic armature that's reaching down from one of the strut trients, like this:

Sorry about the quality of the last two... It's not an easy engine to get info on.

I'm curious, will it have throttle control/the ability to shut it down, or are you going for an exact replica?

[m00f]

Arrgh, I was working on a rs-27a myself, although yours looks much better than mine, as I can't model to save my life. Oh well... I hope you finish this soon, as I cant wait to see what I could have made.

[Agathorn]

@specs

Look at it mounted on the Delta 2 first stage though, and you see none of that. When looking at it on a test platform, you obviously have everything exposed, and additional support structures as well. And yeah reference isn't so good. It is making it tough

@m00f

Thanks for the compliments! In my case I work in the VFX industry and went to school for this stuff. Though i'm rather rusty as I don't do a lot of modelling anymore these days.

[Agathorn]

I'm curious, will it have throttle control/the ability to shut it down, or are you going for an exact replica?

Sorry forgot to answer that. Right now my intention is just to provide the models for other moders to do with as they desire.

[m00f]

file:///C:/Users/caseymo/Downloads/IMG_20140119_102711%20(3).jpg

Here is a pic of my notebook if you want some of the info that I found. Also, it is in .64 scale, as per KSP standards, although the mass and gimbal range is a little high

[MaverickSawyer]

Uhm... We can't see the pic, since it's referring to a spot on your hard drive. >.>

[DasBananenbrot]

file:///C:/Users/caseymo/Downloads/IMG_20140119_102711%20(3).jpg

Here is a pic of my notebook if you want some of the info that I found. Also, it is in .64 scale, as per KSP standards, although the mass and gimbal range is a little high

You need to upload the picture to a site like imgur first and then post the link...

[Woopert]

Awesome start here. Are your plans to recreate all of the well known and famous engines in KSP? Hope you get enough time to finish these, but personal life comes first.