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SABR3 Sterling v0.4.0 Pre-release [KSP 1.7.x] [Apr 24, 2019]


JadeOfMaar

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Finally revisiting this. Engine cowls (so that these things fit properly on other tanks) are on the list.

New plumes and some very minor geometry fixes. I tried to patch the stock Rapier but it refused for some reason. The large center engine is the included SCIMITAR Advent.

1rcEaQj.jpg

SABREs in Air-Breathing.

WIKtyl6.jpg

ZFRXlUs.jpg

SABREs in Closed-Cycle.

oxesaJ8.jpg

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  • 1 month later...

I finally got around to making those engine cowls. As requested, they'll allow for flush-mounting these engines to things other than their intercoolers. I haven't launched anything yet to see what the drag cube system does with them. Their colliders need a second pass before I can release them.

Qmonnr8.jpg

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Pre-release 0.3 is here

See all screenshots above for highlights. Please don't mind the broken normal textures. Next update should come very soon, fixing all that.

  • Obsolete -> Rapier-replacing engine
  • Minor adjustment to performance rescale
  • Update/replace plumes
  • Minor geometry fix/adjustment on SABR2 intake and SABR3 rocket(s)
  • Minor balance pass on intakes
  • B9PS updates and joint strength buff on SABR3 intercoolers
  • Added engine cowls

:: DOWNLOAD ::

Edited by JadeOfMaar
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  • 2 months later...
8 hours ago, linuxgurugamer said:

How have I missed this up until now? And is there an anticipated release date?

:sticktongue: I thought you were aware of this already, and not interested... There has been no set release date.

7 hours ago, Redacted said:

Is this compatable with 1.6.1 ?

Well... The thread title says "1.6.x" in it. ;)

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@JadeOfMaar

Gave it a detailed look today and here's my initial thoughts...

1)Your models and texturing are most excellent and for a yet to be released mod this was a very pleasant surprise. Furthermore, the new objects (motors , cowlings ect.) fit very nicely with the rest of the KSP content. Only thing I would ask for here would be the option to integrate heavy landing gear into / onto the largest of the inter-coolers. Would be more streamlined and look allot less like an Albatross on the runway.

2) On my first flight I did have a issue where the motors (Precedent) would rip off the wings (BIG-S Delta's) during assent. Don't think I got past 6000 meters before losing both wings to sudden structural failure. What I ended up doing was mounting a single Precedent to the end of the MK4, while using Advents on the wings. This configuration worked out really well and could be even further improved upon by maybe swapping out the one of the closed-loop engine cores for a different liquid rocket. 

3) On my third try I was able to reach orbit using a 153,000 Kg SSTO with less than 50 parts. (no cargo) While this may not sound significant, keep in mind that my prior SSTO had over 120 parts including 16 Scimitar engines. This weighed and cost just over twice as much too! IMO this is one of the biggest issues with SSTO's in general, the part counts climb to stupid levels for a craft that should be kept as simple as possible. 

4) Speaking of Nukes, i previously inquired and said it would be a really nice option. Yet i do see that the way the Turbo-Jets / Rocket -Bells are separately parted, it should be possible to add nuclear using the Stock KSP content or some of the Near Future motors. (Love the parting BTW, far as i know of this is the only engine mod that does this.)

5) The PWB fuel-balancer (Linuxgurugamer's) mod is a must have with these motors and most SSTO's in general. I forgot to add one and had one hell of a time staying at the correct insertion angle during re-entry.

 

Question: Have you considered using Toroidal Aerospikes vs the Motor Bells? Mechanically Aerospikes are simpler, lighter and provide for more consistent thrust / ISP regardless of atmosphere. While I realize that your trying to stay true to the original Saber concept, this would be really nice to have as a side option if it were later available.

 

Edit: Just realized that the intercoolers make O2!  HolyCow Batman

 

Cheers!

Redacted

Edited by Redacted
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Alright... Swapped out the Rocket-Bells for the "Kite" R1-D liquid Fuel engine. Altogether I have three, with one in each "Advent" inter-coolers / turbo-Jets (Mounted on each wing) and one in the Precedent Turbo-Jet / Engine Cowl (Mounted rear on MK4). This decreases the weight by about two tons while increasing the overall thrust by 600 KN.

Kite Spec's" 3 Tons, 932KN & 303 ISP (ASL) / 1000KN & 325 (VAL)

This thing gets to low orbit so quick I hardly have time to use Mill power to generate O2.

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@Redacted Well then:

  1. Thanks for the compliment on the models. They could be better, or the use of shaders on them could be better. Something is planned to happen for the latter. There will be no such option to integrate landing gear. If you lookup a SABRE engine you'll see that the entire internal volume is used by the intercooler mechanisms and the engine itself, and if you lookup the Skylon plane itself, you'll see that its wheels are never that far apart. They're always near the wing root.
     
  2. I've made a few efforts to deal with the weak joint strength of the nacelle to the wing, short of making it autostrut itself to grandparent. Surface attachment is generally weaker than stack attachment. Add onto that the weight of the nacelle body, the weight of the IntakeAir it holds (by design), and the weight and peak thrust of the engines. It's mandatory to autostrut the nacelle or through the nacelle.
     
  3. Part count (and by extension, drag) is a major part of the purpose of this mod. Anytime someone measures part count with this, I know they're talking savings.... 16 Scimitars though??? I don't think I want to know. Lol.
     
  4. I've considered dividing the power between the ramjets and rockets differently. I've been informed that the rockets produce the lion's share of thrust so I'll be testing that and likely reducing the ramjets to just a booster (likely 30%, possibly 20% from their current 50%) for the 0.4 update. Thanks. Yes I'm absolutely sure that nobody else divides their SABRE-based engine.  It adds fidelity and fun to the craft design.
     
  5. Nukes will not happen in this mod additionally because I believe that a sufficiently large nuclear jet engine core to move a spaceplane on a runway would be mutually exclusive to SABRE intenals, and one engine is designed to intensely suppress heat while the other is designed to fully exploit heat. I cannot see them mixing.
    You might like to add @Snark 's Attitude Adjuster on top of PWB. This grants you dynamic control point orientation, arguably the absolute best for helping you hold your heading during reentry.

No I haven't considered toroidal aerospikes. In another of my mods I do give the stock aerospike some gimbal and a more proper Isp curve, making it far more usable as it should be. For SABRE, nothing except its own very unique "turbo rocket" will work to efficiently get the Skylon plane moving on the runway so until it reaches liftoff speed, every other engine will likely still horribly waste fuel. In the 0.4 update (as previously mentioned) I'll be changing how these engines behave. The rocket nozzles will appropriately gain and carry the core jet engine behavior. Players will likely start replacing their choice turbojet combinations with SABRE, rather than replacing the SABRE with nuclear, etc.

The core of SABRE is not its "turbo rocket" engine, it is the intercooler's ability to produce Oxidizer mid-flight. Unlike other mods that freely grant it to the point of being wildly OP, I ensure that it's available when it's needed, and unavailable when not needed. It's always on by default so be sure to action group it to turn it off in the late ascent phase, otherwise you'll gain Oxidizer on reentry and become needlessly heavy then.

Edited by JadeOfMaar
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Responses...

 

1) A few years back i was a serious modder, creating models, textures and scripting. Unfortunately my community imploded from all the jerks that took balencing way too seriously. They’d rather have a stale game than see something new. To introduce a new variable(s) in their eyes could unset the balence of play as well as any perceived advantage of skill.

2) It could be worth it to add a custom Wing better match the Engine. This way at least you’d have more control over the strenght of the connections. Beyond that, weight / drag is a big issue and to be honnest i was a bit surprised to see how easily the engines came off. Hell at one point before I enabled struts, the entire wing assembly (both sides) fell to the floor before i could throttle up. Its possible that the stationary engine mass can’t cope with the sudden injection of the game world physics. Instead of too big to fail, it’s too big to fly.

3) If i get chance later I’ll post a few pics.

4) I’d suggest that you get more feedback before tweeking stats. Reason being is that being a new concept its shouldn’t be held to the same standards as other engines. Otherwise your just reinventing the wheel, tho be it with newer models.

5) I have figured out a way to add small nuke engines (Eel, 0.35 Tons) while keeping the Kite Liquid Fuel motors. all while within the same intercooler. Should allow me to do efficient / small orbital maneuvers while generating a few EC’s on the side.

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@Redacted That's very unfortunate. :( I get the same feelings at times, and see related things that you only see when you become a big and passionate mod maker. I'm not out to burst your bubble. I'm rather fond of sci-fi, and things beyond the effectively similar mass rejection of mods by players at large... However I'm not particularly liberal with this mod as it specifically has a narrow scope.

I've thought of making parts to help make a Skylon plane body apart from the engines, but I've purposely left that for other part makers to do, like the real Reaction Engines Ltd company who will make only the engines; let the other brands make the body... But that mightn't happen until I release this and they see it, oddly enough. I have a whole fuselage (or several) of my own planned already. Fleshing out SABR3 would be just a distraction. ;)

Looking forward to those.

I like your point #4. I much rather like advanced engines other than the SABRE. I'm fond of scramjets, the concept plasma jet engine, and a sci-fi jet engine concept I devised based on that and hopefully superior to both. To that end, the concept of the RAPIER doesn't hold my interest much, however, with respect to you, I won't nerf the ramjets too much, then.

I want to see this combination.

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Here is a short video showing the build for the modified engine. Be aware that this is not the complete vehicle just a walk through of what was done.

 

Please notice that I am now attaching the intercooler directly to the chassis then sliding it away from the build and finally attaching wings to the chassis. This way the wings are not supporting the weight of the motors. Despite this build change, the wings still snap off. Hence I don't think that this is an issue of the intercooler but rather the Wings themselves. See the last few minutes (past 8 minute mark) of this video for details.

Developmental Flight: 

 

 

 

Edited by Redacted
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@Redacted That's a very nice looking plane, but everything I've seen wrong (from design through flight) is due to pilot error and not a shortcoming in my parts (you should still autostrut my ramjet to grandparent though. I know very well that joints are flimsy in that area.). :sticktongue: I can call a somewhat long list of the things you could have done better for a satisfactory test flight but I'll only name the relevant thing(s): You tried to pull up while traveling too fast, too steep, too deep in the atmosphere, with too big a plane, and while thrusting directly towards the ground with epic Nertea engines, which only helps to make the situation worse. This was not a valid test at all. :D If the wings broke off when you pitched up for the steep climb into space I'd totally understand and to which I would say that's a stock problem and neither a fault of my mod nor MkIV Spaceplane.

Edited by JadeOfMaar
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@JadeOfMaar Unfortunately with the controls, there isn't in any sense of the word, "fine control". A short press of the keyboard is the equivalent of full deflection until it's released. Often this can cause the change in heading / vector to overshoot or oscillate wildly. I suspect that the majority of Keyboard players deal with this problem in one sense or another. Now as for the breakage, this took place when power was reapplied. On other flights where i waited for the re-entry speed to slow below 500 ms, I was able to restart the turbo-jets without the craft coming apart. Odds are that the sudden injection of thrust during decent was enough to over stress the the Turbo-Jets (which came off first) then the Wings.

Well anyways, i did find one serious error. While the Saber engines work great all on their own, any other forms of propulsion added, often doesn't show it's potential DV on the staging panel. Doesn't matter if the extra motors are within the intercooler or not, they just don't show properly 100% of the time. In may cases I have not idea how much ms I have left to be able to accurately gauge a burn. You can see this in the Developmental video i posted earlier.

Edited by Redacted
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@Redacted Ah. Yeah. Caps Lock helps to some degree (that's the toggle for fine control. Works best with RCS and docking) but you're quite right in the "binary" nature of a key press is quite a shortcoming that all keyboard players have to deal with. on second look I think you could have saved the plane if you could pull up more reliably while in the upper atmosphere. But clearly, either the center of drag went far forward or the center of mass went far back, or maybe you needed a bit of forward control surface.

The source of your staging problems is in the stock delta Vee. Squad introduced an uninformed assumption about how players (should or should not) build their craft. It assumes stages always end with an engine so it does not measure dV for the not-too-rare cases where a player will attach something after an engine and offset it out of the thrust transform's way. It will not measure dV for an engine attached through or after my ramjet array. So you may want to resume hugging KER's dV panel and even turn off Stock dV. :/

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@JadeOfMaar 

Been having much better success with the MK3 platform. I've stuck the shock-cone / intercooler up front as the "nose" of the craft, while the engine cowling naturally sits at the rear. The wings have been replaced with stubs, making the entire profile very sleek. With this i was able to drop 1500 unit of ore into an 300 km orbit and return without imploding. (mostly luck) Overall, the design is made to land using chutes, ditching it's landing gear shortly after take off. (Saves weight and allows for a efficient profile) The craft it's very skill dependent, relying totally on the pilots ability to manage a fine balance between generating O2, climbing and liquid fuel conservation. Furthermore, once the engines have been shut down, the atmospheric control authority is all but non-existent.

Will post a pic or video later.

 

Edit: IMO the key to making good use of the Mk4 is taking advantage of the lifting body while using minimal Wings.

-Redacted

Edited by Redacted
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Here's is today's improved flight to 300 km and back Dropped off 1500 units of Ore. Later landed safe and sound. I did however try to feather the air-brakes, losing one in the process during decent.

Note: This version uses disposable landing gear and jettisonable tanks mounted through the Advent motors. In most cases the disposable LF tanks and the landing gear have been recovered after the fact.

 

Edited by Redacted
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