Realism Overhaul Discussion Thread

[kyoden]

Greetings, I am attempting to make my own Falcon 9 FT, staying as close to specs as possible.

The problem I run into is as soon as my craft leaves the launch clamps, it starts getting real whobbly at the stage 1 to 2 interstage, then the craft goes where it pleases, it seems to only do this when a Merlin engine is there, not with a J-2 (I've tried others and they work fine). I've attached the KerbalX location of my craft, and some screen shots too.

https://kerbalx.com/kyoden/Falcon-9-Full-Thrust

 

[Phineas Freak]

@kyodendo you have KJR installed? Judging from the stock engine interstage fairing around the engine i would imagine that you are trying to mount the second stage to the first stage via the engine only. This will not work all times (as you have found). It is better to use the ability of the engines to surface - attach: at first mount the second stage at the interstage adapter node and then attach the engine on the second stage.

Physics and rigidity in KSP are affected by the part mass: if you attach two heavy objects via a (relatively to them) light object then a wobbly Kraken will ensure.

[Combatsmithen]

6 hours ago, Phineas Freak said:

@kyodendo you have KJR installed? Judging from the stock engine interstage fairing around the engine i would imagine that you are trying to mount the second stage to the first stage via the engine only. This will not work all times (as you have found). It is better to use the ability of the engines to surface - attach: at first mount the second stage at the interstage adapter node and then attach the engine on the second stage.

Physics and rigidity in KSP are affected by the part mass: if you attach two heavy objects via a (relatively to them) light object then a wobbly Kraken will ensure.

 

Your sig tho. "We choose to go to the mun, not because it is easy, but because the other things are too hard." That is one of the best sigs.

[Yurkass]

I need advice

is it bug or not bug -- "Engine gimbals will not work until  activate the engine through staging, even if you toggle them on with an action group. " ?

how to activate the engine via the Action Group and not to break the gimbal?

Thank you

Edited June 7, 2016 by Yurkass

[kyoden]

On 6/7/2016 at 1:29 AM, Phineas Freak said:

@kyodendo you have KJR installed? Judging from the stock engine interstage fairing around the engine i would imagine that you are trying to mount the second stage to the first stage via the engine only. This will not work all times (as you have found). It is better to use the ability of the engines to surface - attach: at first mount the second stage at the interstage adapter node and then attach the engine on the second stage.

Physics and rigidity in KSP are affected by the part mass: if you attach two heavy objects via a (relatively to them) light object then a wobbly Kraken will ensure.

Thank you for your attention.

Yes, I do have KJR.

I am not sure if I understand completely, but the picture attached is with some questions.

I tried but even worse result. I realize the engine can't sustain the weight, but I can't find a better way to mount this, Do you know of a particular part that may help?

Strange thing is, is when I used a KW interstage fairing (it opens like a flower, and has a bottom, middle and top node), without an engine mounted it worked fine, but once I add the Merlin, wobbly again, even though the engine wasn't supporting anything (attached it to the middle node). I don't have a screenshot on that cause it's real late for me and KSP just crashed.

Thanks again for your help, it is much appreciated.

[Phineas Freak]

@kyodenBefore continuing: can you temporarily rebuild the rocket as it was before and replace the engine with a random one from another pack (i.e. not stock or VSR)? VSR currently has some issues with the "tank butt" fairings (the small attachment node that you have captioned "Where should this be attached" - ignore it, this is for the stock game) breaking FAR and doing all sorts of weird things.

Second thing: all RO engines are surface attachable, meaning that you do not need an open attachment node to mount them. Ignore all the attachment nodes of the engine, mount the tank on the interstage adapter (as you have already done) and then surface - attach the engine at the bottom of the tank. To get only one engine there is a trick for that: increase the Symmetry Mode to two and try to "clip" one engine into the other (this will center the engines). Then drop the symmetry to one again and attach the engine (be careful not to disturb your mouse while clicking!).

Update: FAR and some specific engines from VSR do not play well with each other and the Merlin is one of them. Just tested a Falcon 9 v1.1 with just the minimum to confirm this.

Edited June 8, 2016 by Phineas Freak

[kyoden]

19 hours ago, Phineas Freak said:

@kyoden

Update: FAR and some specific engines from VSR do not play well with each other and the Merlin is one of them. Just tested a Falcon 9 v1.1 with just the minimum to confirm this.

Aha, I will try without VSR. Thanks for figuring that out!

Update: Removing VSR did the trick! Unfortunately though, the engines are quite bigger, and uglier, but I don't mind! Oh and had to remake it because it started acting funny in the SPH.

Edited June 9, 2016 by kyoden
update

[Dashman]

I havnt spotted my problem in this thread anywhere but im sure its somewhere and I missed it...

Firstly, what a mod to this game! I have caught myself physically smiling at how good it looks and feels to get something into orbit and beyond.

Its the 'beyond' Im having trouble with.

I can get my payload into orbit but as soon as I try to make a burn for a planetary intercept with say, Mars, the burn happens ok. I shut down the engine

and without any thrust it appears to keep burning. Its not burning or using any fuel but my orbit increases and the dV figures just keep going up.

This basically means I cant get to any other planets as I cant do a precise burn. Im using a few added mods but the engines im using in this case are just the stock engines with RSS configs.

Im sure others have had this and maybe someone has an answer. Any donations greatfully received

 

[Phineas Freak]

@Dashmana good candidate for that would be the stock "orbit" bug. Other than that, do you have RCS onboard? With KSP 1.1 RCS can act like an engine if the throttle is other than zero and RCS is enabled.

[Dashman]

Thank you PhineasFreak for you response. Ive been looking up the orbit bug you mentioned...I know Ive heard mention of it before but cant find a thing on it.

Do you or anyone else have any suggestions as to a fix or to point me in the right direction? I am aware of the RCS issue but I know its not that. The burn will continue at the same thrust after engine shut down...no RCS involved. Its a weird one. I guess thats what a bug is lol

Edited June 10, 2016 by Dashman

[Phineas Freak]

@Dashmanso when you press "X" to shut the engine(s) down they continue to thrust? Huh, that's a really weird situation...

[Comet Tail]

On 6/7/2016 at 11:10 AM, Yurkass said:

I need advice

is it bug or not bug -- "Engine gimbals will not work until  activate the engine through staging, even if you toggle them on with an action group. " ?

how to activate the engine via the Action Group and not to break the gimbal?

Thank you

I've actually noticed a similar problem that may be related - I've built a few craft now where the engines don't gimbal. I guess I have to use the stage command to ignite them in order for their gimbal to work?

Also, question; I've noticed the Co2 scrubber produces water at a rate of 0.00329... So, in other words, in one day, the scrubber will dish out 284 liters of water per crew member? Is there a zero or a few missing here? I don't think my six kerbals are drinking a few liters a day and exhaling a thousand liters to the dehumidified out of the air...

 

Tempting to get a big powerplant, an electralysis plant, collect the scrubbed water and turn it into Hydrolox fuel for a nearly unlimited fuel supply, though, limited only by my Lithium Hydroxide to keep the Co2 Scrubber running XD

[crasher925]

whats the best mech jeb settings for assent autopilot?

[rsparkyc]

57 minutes ago, crasher925 said:

whats the best mech jeb settings for assent autopilot?

It depends on a lot of things, mainly your TWR throughout your ascent, especially on your upper stage(s).  The higher your TWR, the lower you can make your turn end altitude, but chances are you'll actually wind up circularizing after your apoapsis, so keep that in mind.  Once I'm in space, I usually disable ascent autopilot and just point prograde.  I would start off by setting your orbit altitude to something crazy high (like 9999999), turn start altitude to .5 (km), turn start velocity to 80, turn end altitude to 180, final path angle to 0, and turn shape to 45%, and go from there (mainly adjusting either your turn end altitude and/or your final path angle.  Make sure you also turn on the RSS features in mechjeb, otherwise when you disengage ascent autopilot, your engines will cut out.

[Comet Tail]

This is why I use kOS. I made a C++ script to simulate an ascent and actually planned this thing out

[John FX]

So I decided to use the ION engine in RO. I built my craft and it was good. I launched it and when I got to my ION stage I saw the burn time for my stage was over 5 years, something not possible. Even at 4x warp I would have to burn for over a year.

I know that is a realistic thrust for an ION engine but why not just remove the parts instead of making the parts unusable?

Or include PersistentThrust as a recommended mod maybe.

EDIT :

PersistentThrust causes the ION engine to not work in RO...

Edited June 12, 2016 by John FX

[Mad Rocket Scientist]

On 6/12/2016 at 3:03 AM, John FX said:

So I decided to use the ION engine in RO. I built my craft and it was good. I launched it and when I got to my ION stage I saw the burn time for my stage was over 5 years, something not possible. Even at 4x warp I would have to burn for over a year.

I know that is a realistic thrust for an ION engine but why not just remove the parts instead of making the parts unusable?

Or include PersistentThrust as a recommended mod maybe.

EDIT :

PersistentThrust causes the ION engine to not work in RO...

This was last updated back in 2014, but there's a fork from the 1.0.5 era:

It'll need a recompile and UI re-write, but there's also this:

 

[Charlie the Kerbal]

Having an odd issue with MechJeb / RO working together and hesitantly sending this to RO forum as the issue started after installing RO (and FAR as a dependency). MJ's RO mode is on.

MechJeb was working fine before RO. Now regardless the rocket design and MJ Ascend parameters it starts pulling to rocket towards 180 degree some time after the launch. I though it might have been performing gravity turn with a different inclination but it keeps turning rocket slowly but surely to the point the nose points below horizon. It is not a badly balanced rocket flipping over, I try to correct it manually (which works) but MJ applies the turn again turning rocket to the wrong direction.

I usually end up simply turning it MJ off and fly manually, lots of ComSats in arbitrary orbits as a result.

Any idea on what I might be doing wrong ? 

[Combatsmithen]

2 hours ago, Charlie the Kerbal said:

Having an odd issue with MechJeb / RO working together and hesitantly sending this to RO forum as the issue started after installing RO (and FAR as a dependency). MJ's RO mode is on.

MechJeb was working fine before RO. Now regardless the rocket design and MJ Ascend parameters it starts pulling to rocket towards 180 degree some time after the launch. I though it might have been performing gravity turn with a different inclination but it keeps turning rocket slowly but surely to the point the nose points below horizon. It is not a badly balanced rocket flipping over, I try to correct it manually (which works) but MJ applies the turn again turning rocket to the wrong direction.

I usually end up simply turning it MJ off and fly manually, lots of ComSats in arbitrary orbits as a result.

Any idea on what I might be doing wrong ? 

 

Mechjeb is very hard to get right in RO as its ascent guidance is designed for Kerbin where less burning needs to happen and the atmosphere and planet is nowhere near as big.

[Charlie the Kerbal]

35 minutes ago, Combatsmithen said:

Mechjeb is very hard to get right in RO as its ascent guidance is designed for Kerbin where less burning needs to happen and the atmosphere and planet is nowhere near as big.

It was working perfectly fine with RO in 1.0.5. I still suspect I am doing something silly. Time will tell 

[kyoden]

Have you set MechJeb for special handling in the settings? Also why don't ya y deleting MechJeb and reinstalling the latest dev version?

[Charlie the Kerbal]

15 minutes ago, kyoden said:

Have you set MechJeb for special handling in the settings? Also why don't ya y deleting MechJeb and reinstalling the latest dev version?

Thanks, I was about to, but I just noticed that it was MJ remembering previous Launch to Target Plane setting ! I need to check it a few more times but surely not an RO issue. 

[Herrkurt]

Need help with an issue building craft and I'm not sure if it is with procedural fairings, RO, or both interacting.

I'm trying to build a Saturn I with the basic procedural parts of RO and having trouble. The problem seems like it may be with either procedural fairings or the RL10 engine. Guidance develops a mind of it's own and the whole craft gets wet noodle syndrome with decoupling causing explosive super-sonic accelerations. If I take the payload fairing sides off but leave the interstages normal the rocket behaves (regardless of increased drag). Put the fairing cover on and it goes exploding noodle again. If I replace the arrays of RL10s with single LR-87 H2 at each stage it also seems to go away.

Auto-strutting is off and when I use the RL10 array I have a decoupler in the center of the engines connected to the fuel tank's central node, with a structural part (gird or procedural, happens either way) leading from the decoupler to the interstage fairing which in turn rests on the fuel tank of the next stage below.  The payload fairing at the top is connected to the 3rd stage fuel tank bellow and a decoupler with another dummy payload fuel tank above.

Am I building this wrong?  Is there a way to arrange the interstage that would fix it and allow it to fly normally with payload fairing sides on?

Log: https://www.dropbox.com/s/wkz6wzvsdd5a7pp/output_log.txt?dl=0

-Modlist

RP-0, RSS, RO, [X]science, Filter Extensions, Toolbar, AJE, B9-Proc Wings, BahaSP, Community Resource Pack, Community Tech Tree, Connected Living Spaces, Contract Configurator, Custom Barn Kit, DRE, Engine Group Controller, FAR, FireSpitter, ForScience, Hangar Extender, GCMonitor, KCT, KJR, Kerbaltek, Kerbal Renamer, Kopernicus, KSC Switcher, MJ2, Minimum Ambient Lighting, MiniAVC, Modular Flight Intergrator, Proc Fairings, Proc Parts, RCSBuildAid, Realchute, Realfuels, Realheat, Remotetech, Semi-Saturable Reaction Wheels, Safechute, Scantsat, Shipmanifest, Smokescreen, solver engines, sxt, testflight, texture replacer, TacLS, KAC, VenStockRevamp, Wider Contract App, Module Manager

All kept up to data via Ckan

And craft too: https://www.dropbox.com/s/4wsmwwuag1vxrth/Saturn I.craft?dl=0

Edited June 18, 2016 by Herrkurt
Log added

[Phineas Freak]

@Herrkurtsince you said that you have all the mods updated to latest versions and you are using the VSR version of the RL10 engine then you must downgrade VSR to version 1.9.2.

BTW, there is absolutely no need to use structural parts and extra decouplers for the interstages and the fairing bases. These parts already include decouplers. Also, it has not enough DV even without a payload (edit: scratch that. KER is being stupid again...)

PSA: If you are using Ven Stock Revamp (versions 1.9.3 and 1.9.4) make sure to disable any engine shrouds in the editor (right - click the engine and disable any shroud option that you will find). This will take care of some of the FAR - VSR engines incompatibilities.

Edited June 18, 2016 by Phineas Freak
Workarounds

[Herrkurt]

I didn't even realize VSR was the source for the part in RO.  Not sure how to attach the interstages without a central part.  I assume using the floating attachment point but I was having trouble getting it to attach right.  Any word on is the VSR RL10 is going to be fixed in the near future?  I'd rather not install old FASA for one engine.