[1.1] RLA Stockalike 13.4 [25 Apr]

[Shad0wCatcher]

Thanks Hoojiwana. Saves me from having to dig through more config files. <3

[dzikakulka]

I already said how great this mod is so I'll jump to the thing:

I actually like(d) Cutter having some distinct mechanics. Right now it's cool looking as all the parts and has uses but IMO it's a little bit too similiar to stock aerospike. Just little bit higher thrust, lower Isp, gimbal. I mean, it has its uses but I think those special properties are fun

I wiould be pleased to see more of them actually on other stuff but I realize a lot of people would prefer more stock appearance. That's just my two cents.

[hoojiwana]

I actually like(d) Cutter having some distinct mechanics. Right now it's cool looking as all the parts and has uses but IMO it's a little bit too similiar to stock aerospike. Just little bit higher thrust, lower Isp, gimbal. I mean, it has its uses but I think those special properties are fun

I wiould be pleased to see more of them actually on other stuff but I realize a lot of people would prefer more stock appearance. That's just my two cents.

Balancing aerospikes against other engines is basically impossible. The unique selling point is supposed to be the higher aISP than other engines, but if you do that then it just makes the other engines not worth using on lower stages because they will always be worse. So you have to tread a really fine line between rendering everything else useless for lower stages, and making the aerospike itself useless because it doesn't fill it's own niche. I like to think the Cutter is balanced by having it only really be the best choice below 10km altitude on Kerbin, meaning you'll want to drop them for a T30/T45 if your stage goes above that. Obviously for asparagus staging it is always going to be very good because you drop outer stages quickly, but that's an issue that stems from asparagus staging itself being very good.

I did consider just cutting the Cutter completely before v10 was released because of how hard to balance it is, as well as it not really filling any niche. But I didn't see that going down very well.

The stock aerospike I feel is in a bit of a weird place. The combination of high aISP and low TWR doesn't lead to many times it's a worthwhile option, and it's ridiculous cost and questionable placement in the tech tree just confuses the matter even more.

[Gryphorim]

That's something you'd have to sort out in the Hotrockets thread, I know Stockalike needs a new config for that anyway.

See, I thought that because this now uses ModuleEngineFX natively, hotrockets is no longer supporting this mod.

[hoojiwana]

See, I thought that because this now uses ModuleEngineFX natively, hotrockets is no longer supporting this mod.

It's two things, some engines now having ModuleEngineFX where Hotrockets expects ModuleEngine, and a number of part names changed from Stockalike 0.9.4 to v10. All the LFO engines except the Cutter still use stock FX, as do the SRBs, and the ion doesn't have any FX at all.

[NathanKell]

It also doesn't help that the LV-T series has the efficiency of real aerospikes >.>

At most an aerospike will save you about 15% efficiency at non-optimized altitudes. Bell is always going to be better at its optimum altitude though.

[hoojiwana]

It also doesn't help that the LV-T series has the efficiency of real aerospikes >.>

At most an aerospike will save you about 15% efficiency at non-optimized altitudes. Bell is always going to be better at its optimum altitude though.

Not to mention how engine efficiency changes in atmosphere is incorrect.

[Gryphorim]

I've been trying to write a .cfg to apply the expansion effects to the Cutter. Inspired by the guys making the B9 pack. Unfortunately I just can't get it to work. I can't seem to make hotrockets excerpt out an existing Module{EFFECTS, and insert a modified version with expansion values.

[hoojiwana]

I've been trying to write a .cfg to apply the expansion effects to the Cutter. Inspired by the guys making the B9 pack. Unfortunately I just can't get it to work. I can't seem to make hotrockets excerpt out an existing Module{EFFECTS, and insert a modified version with expansion values.

You are using the SmokeScreen plugin as well? The expansion effects need that to work.

[Gryphorim]

Yeah, I've got that. I am using FPSlacker's .cfgs for the stock engines, I am just trying to get this set to have the same effect with atmosphere so all the parts "gel" together aesthetically. I like the new MP effects that you've created, so I'm trying to make that the particle entity that expands.

[NathanKell]

Not to mention how engine efficiency changes in atmosphere is incorrect.

Not in RF it's not

[Shad0wCatcher]

Dat shameless plug but so very true.

[Nori]

Not in RF it's not

Probably not really the place to ask but how is engine efficiencies incorrect and how does real fuels fix that? Guess I don't really understand all the ways that real fuels changes things.

Edited August 28, 2014 by Nori
Changes not chafes... Darn autocorrect.

[NathanKell]

hoojiwanna: I'll remove this is you like...

Three things stock gets wrong:

1. Engine thrust is directly dependent on backpressure, so engines will always be much more efficient in vacuum than in atmosphere, and further bell nozzles are designed for a specific altitude (i.e. pressure), below or above which they will be less than optimally-efficient-at-that-pressure. Altitude-compensating nozzles (aerospikes) avoid this second type of loss, but not the first (and are never as efficient as an optimal bell at its design altitude). See this wiki link.

2. Isp is a measure of "thrust per weight unit of fuel per second." 400s Isp means 1lb of fuel will provide 400lbf of thrust. In real life, turbopumps don't magically run twice as fast at sea level (pumping more fuel to maintain thrust constant); instead, fuel flow is constant, and thrust varies with Isp.

3. Real rocket engines don't throttle (with *very* few exceptions) and usually can't be restarted either.

There's also of course the problem that stock engines generally have the efficiency of methane/LOX engines but can be throttled and restarted infinitely and fuel and oxidizer has the densitiy of storables (which usually top out at 300s for open cycle and 320 or so for staged combustion)....and doesn't boil off, either.

EDIT: I added #3 in mid flow. Oops.

Edited August 28, 2014 by NathanKell

[hoojiwana]

Dat shameless plug but so very true.

I was asking for it with my post though.

hoojiwanna: I'll remove this is you like...

No need, it's a neat thing for people to read, and to see another way KSP is much simplified from real life.

[Shad0wCatcher]

Yea I suppose just a bit. But I agree in that the difference between completely "stock" gameplay and modded with some realism in mind (FAR / DRE / RF / Engine Ignitor [don't personally use this currently] / RSS [in my case 6.4x to avoid needing human sized rockets for half-pint green pope-hatted aliens]) is stark and absolutely astounding. All we need now is to have that n-body integrator finished up and we can take over the worl...*cough* make the game even more hilarious.

At the risk of becoming even further away from the topic what's the (typical) main problem facing restartability? Cost? Fuel instability? Or are the typical turbopumps just not designed for multiple starts? Genuinely curious.

On topic: I seriously love these engines for my probes and light landers hooji. Thank you for them. <3

[NathanKell]

Answering over on the RealFuels thread

[bs1110101]

I have a bug with the MPR-45 and likely all other monoprop engines. Here's a picture of the ship i'm having the problem on:

As you can see, most of the fuel is in the 4 radial tanks on the outside, which are all mounted on a .5m rcs tank. This small tank emptied and then the engine died, instead of pulling fuel from the radial tanks. RCS seems to still work and pull fuel from everywhere properly, i'm going to go test it a bit and edit it in if i find anything.

[hoojiwana]

I have a bug with the MPR-45 and likely all other monoprop engines.

As you can see, most of the fuel is in the 4 radial tanks on the outside, which are all mounted on a .5m rcs tank. This small tank emptied and then the engine died, instead of pulling fuel from the radial tanks. RCS seems to still work and pull fuel from everywhere properly, i'm going to go test it a bit and edit it in if i find anything.

It's an unfortunate side effect of a stock setting in the Monopropellant resource, here's my answer from earlier in the thread about the same thing:

That's not a bug, that's due to the "resourceFlowMode = STACK_PRIORITY_SEARCH" definition in the engine config, it's the same with all the MP engines as well. MonoPropellant and XenonGas use STAGE_PRIORITY_FLOW, and that can cause a little bit of weirdness with draining from tanks. Unfortunately STACK_PRIORITY_SEARCH doesn't play well with radial tanks, and you can't remedy this with a fuel line because you can't attach them to the radial tanks. So it's a choice between two non-ideal options. As a workaround just use a stackable tank.

You can also use a ModuleManager config to add surface attachment to the stock tanks (I'm sure there's one for this somewhere) or find of the plugins that fixes the fuel flow issue entirely.

[bs1110101]

ModuleManager config to add surface attachment to the stock tanks (I'm sure there's one for this somewhere) or find of the plugins that fixes the fuel flow issue entirely.

That would work, and where would i find any of these? Also, i found an oddity when testing this weirdness: The tiny one that can be radially mounted works when it has no fuel flow, even when stack mounted! I'm going to do i bit more testing, i think it might be fixable by making all the engines surface mountable...

Edit: That isn't why that is, making the other engines surface mountable fixes nothing, any idea why that one works?

Edit 2: I fixed it!

Anyone want the configs?

Edited August 31, 2014 by bs1110101

[hoojiwana]

The tiny one that can be radially mounted works when it has no fuel flow, even when stack mounted!

Well that needs to be sorted out, not a big issue though. I did also notice the radial version is the wrong size, so that's another minor thing to fix at some point.

Edit 2: I fixed it!

Anyone want the configs?

It's a simple matter of commenting out the "resourceFlowMode =" line in the configs, and if you do that you'll just end up seeing the engines taking MonoPropellant from outside of their stage when they've used that stage up, even through decouplers apparently. I recommend keeping the settings on the engines as they are and using a fuel flow plugin instead, or enabling surface attachment and adding fuel lines. To do that, change "attachRules = 0,1,0,0,1" to "attachRules = 0,1,0,1,1" in the radial Monopropellant tanks, preferably using ModuleManager since that won't change your install.

Edited August 31, 2014 by hoojiwana

[wasmic]

Wow, the new MonoProp engines are awesome! Love them

[hoojiwana]

Removed image.

Work-in-progress shot in Blender. Gold foil needs some work still, and this particular picture is just the diffuse. I'll also be adding normal maps to these parts, but since they're all 256x256 the memory hit shouldn't be too bad. Worth it to add the detail the foil needs to look convincing I would say.

Edited September 4, 2014 by hoojiwana

[Rumcajsev]

Looks really cool. Are you thinking about making some new probe core shapes?

[hoojiwana]

v11.2 released, fixed up some issues with the tiny MP engines, reduced the small radial decouplers force by roughly 50%, and increased the big MP aerospikes ISP to make it a little more competitive.

Looks really cool. Are you thinking about making some new probe core shapes?

Yep! So far there is square and round probe cores in both gold foil and stock(ish) grey in the same style as the HECS and OKTO, and I'm open to suggestions for more, as well as any probe-ish parts you might want.