[1.3.0] Kerbal Engineer Redux 1.1.3.0 (2017-05-28)

[Kobymaru]

I can't really see much point to it, what would you actually use it for?

In order to get how my craft "feels" under different internal flux conditions.

The internal flux vs radiation flux values already DO give me important information: am I loosing heat faster than I gain it? However, those are only dynamic values, and an average temperature would give me a static value, i.e. the "amount" of heat currently in my craft.

Alternatively to the unit Kelvin, you could simply write out fictional Joule values, which would be the sum of the temperature (unit K) multiplied by the Thermal mass (Unit ???).

It's not strictly necessary, I just thought that if it's not too hard to implement, the craft temperature could be somewhat useful.

[Tarheel1999]

So I have this weird problem with a craft in the VAB rapidly changing the DV calculation between two states. Also I'm having an incorrect DV calculation related to fuel lines that I think may be related. I'm not sure the problem is with KER, it may just be making the problem visible. Has anyone seen a similar issue?

You need to post a pic of your craft in the VAB/SPH

[StahnAileron]

I'm having a problem where the deltaV remaining for the current stage disappears when the engine(s) are firing. I'm using Real Fuels with the stockalike configs. Is anybody else seeing anything like this?

I'm having a similar-ish problem. My spaceplane dV's aren't reading right when I switch engines from jets to rockets. At least with jets I get some sort of reading, but rockets tend to give a NaN output. I'm also getting log spam:

[LOG 22:48:21.032] dT is NaN! tA: NaN, E: NaN, M: NaN, T: NaN

I am running a lot of mods, but MechJeb is reading dV correctly. I could sorta live with the dV output being wrong since MechJeb could substitute (though I like the HUD nature of KER better), but the log spam is something I'd rather not have. I have an 18MB log file and MOST of it is the above line.

[mjpburke]

I tried KER last night for the first time, I'm a die hard for the core game. My only indulgence is chatterer.

I started a whole new game and KER worked great until I started doing stages. The first rocket I did with a stack separator KER only displayed 0 values for TWR and several other values. All I am still seeing are values for mass and fuel.

I tried adding the 2 different parts of KER to my rockets to get it to work and switched between career and partless with no change to 0 values being displayed.

Does anyone have any ideals as to what is up?

I really like the mod and would like to continue using it...

[Nansuchao]

Was your stage set correctly?

[Padishar]

Due to certain limitations in the current code, the deltaV calculations only work if you do not decouple the root part of the vessel from the rest. What this basically means is that you should use the "root" tool in the VAB to make sure that a part of the payload is the root.

Also, to workaround a problem in the stock game, after changing root it is a good idea to detach all but the new root part from the vessel (or as much as possible) and then reattach it. Otherwise you may have problems with RCS, Xenon or jet engine fuel draining from tanks in the wrong order.

Can you post a pic showing your vessel and the KER window (set to be not compact and to show all stages) and indicate which part is the root?

[cephalo]

The issue went away. The problem may be that I started with a fuel tank and then after I added the control module I set that as the root. Anyway, when I went back to it on a new session everything was fine and I could play with the fuel lines and everything worked.

[KristopherKerblumbus]

I've been looking through the thread and have not yet seen an answer to this question, so a thousand pardons if it's been answered before: But has anyone unraveled the problem with the TWR in the SPH/VAB being different (e.g. higher) than what the readout is in flight? Makes it INCREDIBLY difficult to design VTOL's now. I don't think it's a mod problem, as I've run this on my heavily-modded install, and on a stock install with only KER installed.

[Red Iron Crown]

I've been looking through the thread and have not yet seen an answer to this question, so a thousand pardons if it's been answered before: But has anyone unraveled the problem with the TWR in the SPH/VAB being different (e.g. higher) than what the readout is in flight? Makes it INCREDIBLY difficult to design VTOL's now. I don't think it's a mod problem, as I've run this on my heavily-modded install, and on a stock install with only KER installed.

Are you using jets for the VTOL propulsion? Jets lose thrust with altitude and follow a curve related to speed as well (thrust rising and falling), there are sliders to adjust the altitude and speed values used for calculations in the VAB.

The other thing it might be is looking at vacuum values instead of atmospheric ones for rocket-powered VTOLs, all rocket engines produce less thrust in atmosphere (sometimes dramatically so) so the vacuum values should not be used for atmospheric performance.

[KristopherKerblumbus]

I would have felt REALLY embarrassed if I missed something that simple. :-/ Unfortunately, something else seems to be going on here:

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The first image is outside the KSC, showing the max TWR of the craft (bottom right) at 1.17. The second image in the SPH, I tried to show that the horizontal engines are deactivated and only the VTOL engines are registering with KER. As you can see in the image, it's showing 1.27 TWR. Not a huge difference here, but the difference scales with the size of the craft.

[Red Iron Crown]

OK, now that is odd. The runway is a bit above sea level, but I don't think 70m or so should make that much difference in thrust.

[KristopherKerblumbus]

Well, I've come to the conclusion that it may be one of two things: Either the changes in the souposphere post 1.0 haven't been properly accounted-for by KER yet (doubtful), or, it's that I'm running 64-bit. It's probably that. But I've been running it for so long without any major bugs I don't even think about it now when it loads up and spits out all those warning messages. I just click through them reflexively...

[Kobymaru]

Hi, I am having trouble to get KER to display the Delta-V of my craft. It's an SSTO and as soon as I switch the Rapiers to Closed-Cycle, the Delta-V readout jumps to zero even I have plenty of fuel and the engines work

This happens both inside and outside of the atmosphere.

When I fly higher up, closed cycle shows 0m/s and open cycle shows NaN m/s.

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I have no staging, and not a single fuel line in there. Really no Idea what I did wrong here.

[Padishar]

Is this a stock vessel? Can you upload it (and give details of how to fly it)?

- - - Updated - - -

Well, I've come to the conclusion that it may be one of two things: Either the changes in the souposphere post 1.0 haven't been properly accounted-for by KER yet (doubtful), or, it's that I'm running 64-bit. It's probably that. But I've been running it for so long without any major bugs I don't even think about it now when it loads up and spits out all those warning messages. I just click through them reflexively...

The performance of jets also depends on air density which depends on temperature which depends on the time of day. Whether this is enough to account for the difference I'm not sure. The reported thrust is 210 in the VAB but only 193.57 in flight.

Edited September 22, 2015 by Padishar

[Kobymaru]

Is this a stock vessel? Can you upload it (and give details of how to fly it)?

Yes, it's a stock Vessel, hower it's very awkward to fly and I don't want to waste your time. I found a much simpler way to trigger the bug (or maybe a different one, lol)

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Apparently, if the tank that contains the Oxidizer does not have any more LiquidFuel, the dV readout is zero even if other LiquidFuel is available.

Edited September 21, 2015 by Kobymaru

[Padishar]

Thanks, that looks like a much easier test case to deal with...

I'll try to take a look at it later today. Which part is the root (not that it should make any difference with that vessel, though neither should which tank the fuel is in)?

[Kobymaru]

Thanks, that looks like a much easier test case to deal with...

I'll try to take a look at it later today. Which part is the root (not that it should make any difference with that vessel, though neither should which tank the fuel is in)?

In this case the FL-T400 is the root part. However in all other SSTO's that show a similar problem, it's not.

[Padishar]

Well , I had a bit of a play with it earlier today and there definitely is a problem but I've not yet tracked down the cause. I've got a busy day at work tomorrow but hopefully I should get a bit of time to look at it some more.

[Padishar]

Well , I had a bit of a play with it earlier today and there definitely is a problem but I've not yet tracked down the cause. I've got a busy day at work tomorrow but hopefully I should get a bit of time to look at it some more.

I tracked the problem down to a subtle bug introduced back in April when various optimisations were made to reduce garbage creation. This problem only affected engines that use more than one resource via STAGE_PRIORITY_FLOW so, at the time the code was written, there were no problems but when the rapier was changed to use STAGE_PRIORITY_FLOW in closed-cycle mode the problem started. The problem occurs when the two (or more) resources need to be drawn from different (lists of) parts and the effect on the test craft is for the simulation to try to draw the oxidizer from the liquid-fuel only tank causing it to think it is out of oxidizer so you get 0 dV.

I have sent a PR that fixes this issue. I've only tested it with simple vessels but hopefully it should also fix the NaN issues too.

[Apophis]

I don't know if this problem has been already reported in the previous 48 pages but in the VAB the mass calculated by engineers report and kerbal engineer are differents.

[Padishar]

I'll check later with a range of vessels but can you post a screenshot showing the two different values? Various things changed with how "physics insignificant" parts are handled in the core KSP code and it may be that not all the code in KER has been updated correctly.

[Apophis]

Most of my rockets have wrong mass.

[Padishar]

Weird, I've run tests with quite a few different parts and don't see a difference. Can you upload the .craft file of one of those? Do you use any other mods?

[cpottinger]

I love this mod and consider it one of my "core" mods that must be available before I upgrade to a new version of KSP. So many thanks for creating/maintaining it.

One thing that I would find useful to have added is the current throttle setting expressed as a percentage. When I execute a manoeuvre I will take the displayed burn time of x seconds and begin my burn at t - x @ 50%, or t - 2x @ 25%, or t - 4x @ 12.5%, etc. As it is now, I have to perform the manoeuvre in IVA and get the percentage from a Raster Prop Monitor display, or eyeball the current thrust from the navball for craft with no IVA.

Is there any chance this value could be squeezed in to an upcoming version?

[Red Iron Crown]

cpottinger, if you use the engine's thrust limiter instead of the throttle KER will automatically recalculate burn time. Not 100% what you want but a workaround for some situations.