[1.3.1] Ferram Aerospace Research: v0.15.9.1 "Liepmann" 4/2/18

[ferram4]

Is the log getting spammed with density readings? If so, re-download; I ended up leaving in my density debugging line initially.

[longhornchris]

And we have a winner, thanks Ferram.

[ferram4]

And there's a version 0.12.2 out to fix a sign error in the sweep code that would push the CoL in the wrong direction. It was particularly noticeable with pWings, and has now been fixed.

[NathanKell]

Cool!

While you're pushing out fixes, I have a request that I made a while ago but would like to make again: a way to blacklist certain parts from counting as fairings (since you track by module, not title, for pfairings).

The reason is this:

Even though with RSS settings the drag from the faired engine doesn't matter much, if I understand correctly the wings will also count as faired.

[Soda Popinski]

Thanks for the quick fix. That would explain the SPECTACULAR explosions of space station... or at least one explanation.

[Bugger Burger]

This addon doesn't seem to want to cooperate with Firespitter. What ends up happening is the plane ends up going to who knows where

[ferram4]

@NathanKell: I think that the wings won't by considered to be inside the fairing in that configuration, since they poke out of the fairing. pFairings are handled the same way as any other fairing, and aren't given special consideration based on their module, so you could handle that by simply renaming the part title.

@Bugger burger: Well, you're showing me a NaN error, but FAR isn't capable of causing one of those; it throws the forces out if they're equal to NaN. Could you post a copy of the output_log so we can see what's going on?

I highly suspect something else is to blame here.

[NathanKell]

Ferram: I thought you told me they were*--did you revert that?

*i.e. if the module is present, part is fairing, regardless of title lacking Fairing, Shroud, etc. I tried this a few FAR versions ago and it did seem module based.

[ferram4]

Yeah, I did, when I was going through and setting up the new way that people can manually specify what part title indicates a cargo bay / payload fairing. The titles can now be specified in the config.xml, but there's no special handling for procedural fairings anymore.

[NathanKell]

Ferram: Ah, sweet!

[Bugger Burger]

@NathanKell: I think that the wings won't by considered to be inside the fairing in that configuration, since they poke out of the fairing. pFairings are handled the same way as any other fairing, and aren't given special consideration based on their module, so you could handle that by simply renaming the part title.

@Bugger burger: Well, you're showing me a NaN error, but FAR isn't capable of causing one of those; it throws the forces out if they're equal to NaN. Could you post a copy of the output_log so we can see what's going on?

I highly suspect something else is to blame here.

Here's two output logs in one ZIP folder. Pastebin won't allow me to paste them due to the file size, so I put them in a Zip folder.

http://www./download/1vmtuj7yscfh9wh/Logs.zip

They only seem to crash when I'm recording with Fraps.

I have a feeling it's something to do with the Biplane's wings, because for some odd reason a propeller plane can reach speeds of Mach 1 and beyond

http://i.imgur.com/hcbIaD4.jpg

http://i.imgur.com/QF6KHVX.jpg

Like I mentioned earlier, some even go insanely fast, enough to crash the game.

http://tinypic.com/r/29fz3ua/5

[Sirius]

I seem to be having a strange issue with the CoL whenever my rockets are in the vertical position. I have version 12.2. The rocket flew just fine before install.

Edit: Adding control wheels helped the issue, so it looks like it's just an appearance bug with CoL.

Edited December 18, 2013 by Sirius

[ferram4]

@Bugger burger: If you're using the new biplane wings, those aren't affected by FAR; Snjo is using his own special type of lifting module for that, so you'll have to bring it up in the Firespitter thread.

@Sirius: That's intentional. How are you supposed to determine the stability of your rocket if the CoL doesn't tell you where lift will be produced in a given direction when you pitch up?

Also, why are you putting fins where they will destabilize your rocket?

Edited December 18, 2013 by ferram4

[Andon]

I BELIEVE that's because FAR adds a little bit of lift to some/all of the pods (Including the MkI pod). Not a lot, so you won't really notice it, but it might be enough to knock the indicator funky if you're using a few fins.

[Sirius]

the fins were to try and correct it, they were not on the ones I flew. Prior to the installation of FAR, the CoL doesn't point in ANY direction. It's just a solid circle. This is where I got confused.

[pina_coladas]

I seem to be having a strange issue with the CoL whenever my rockets are in the vertical position. I have version 12.2. The rocket flew just fine before install.

Edit: Adding control wheels helped the issue, so it looks like it's just an appearance bug with CoL.

FYI I was getting weird effects like this on a pure stock 0.23. It might not be FAR at all.

[Sirius]

FYI I was getting weird effects like this on a pure stock 0.23. It might not be FAR at all.

Well without making changes then installing FAR I got the odd CoL. When I noticed the same ship pitch off out of control I looked at the CoL and saw it was 'wonky'. I uninstalled FAR as my first step, rebooted KSP and saw the CoL was a solid circle. Re-installing FAR made the CoL wonky again. Tried adding fins, tried a completely new build. Even a Mk1 with nothing attached has the wonky CoL.

[Frostiken]

So a while ago I used FAR and I quit because it was completely unintuitive and causing obscene problems that made no sense. I thought I'd give it another shot.

Here is my completely unflyable rocket.

Halfway up it will suddenly flip over and 'stabilizes' flying parallel to the ground. Every single time. There is no way to not do it. What kind of asinine physics decide that the 'path of least resistance' is to flip completely perpendicular to the direction of travel? This is the kind of unpredictable, utterly unexplained silly asinine crap that caused me to quit using FAR last time.

Edited December 18, 2013 by Frostiken

[Camacha]

So a while ago I used FAR and I quit because it was completely unintuitive and ridiculous. I thought I'd give it another shot.

Easy there, partner. Just because you do not understand something does not warrant a reaction like that. A lot of people are flying with FAR and are having a lot of fun with it. Please consider that you are very used to stock behaviour. That means that changes to it might seem counter intuitive at first, because it is very much outside what you are used to. If you read back in this topic, you will see that a lot of problems have with FAR actually stem from a lack of understanding what is going on, and is no fault of the mod. In reality, the stock behaviour is much more 'made up' than that of FAR and is the more counter intuitive one when compared to reality, but you are used to it and the effects it has on craft.

Also consider that a new version of KSP has just been released, so it is possible that there are some bugs in there.

Looking at your craft, it appears to me that it has quite a high thrust for low weight. Vehicles tend to loose control with FAR when pushed too hard through the atmosphere, so that might be what is happening. Also, are you aware what happens when the fuel drains? Maybe a shift in CoM changes its behaviour. I would start by adding some fins to the bottom and switching the two SRB nose cones out to something a bit more aerodynamic (like the black and white cone with a small nosecap). That way you basically add some drag to the bottom and remove some on top, helping it stay upright.

Edited December 18, 2013 by Camacha

[Ralathon]

So a while ago I used FAR and I quit because it was completely unintuitive and ridiculous. I thought I'd give it another shot.

So let's try this.

1) Take the regular pod. Put a parachute on top. Put three regular LFT fuel tanks underneath with an -45 engine at the bottom.

2) Stick two radial decouplers on the sides in the middle of the second fuel tank, put two big boosters with a nosecone on.

3) Rocket decides halfway up to simply, suddenly, randomly flip over. Every. Single. Time. There is no way to simplify this build.

This is 'improved physics'? This silly asinine crap is exactly why I quit using FAR in the first place. There's no planning for this or explanation as to why it would just randomly decide to flip over for no reason.

Completely unflyable.

Think about it. The center of mass goes down as the rocket goes up. When you don't point precisely prograde the air will push on the sides of the rocket. If your CoM is high up most of the air pressure will be below it. So it tends to stabilize the rocket by pointing it back to prograde. If your CoM is low the situation is reversed and the air tries to point the rocket away from prograde. See this picture:

If your rocket flips out it means you're going so fast with such a low CoM that the air pressure overrides your SAS control. Either go slower or make your rocket more top heavy. What you're currently doing is akin to waving a flag and getting frustrated when it points itself pole first.

Reality is complex, think about things before claiming a mod doesn't work.

[Frostiken]

Don't solid rockets burn from the bottom up? The mass should be shifting up, not down. I can retain 100% liquid fuel in the center stack and the burning action of the SRBs causes the flip.

If the mass is shifting down as they burn, well, they're programmed wrong. That's either a bug in the base game or a bug in FAR.

Edited December 18, 2013 by Frostiken

[Camacha]

Why should the center of mass on a solid rocket booster be shifting down? They burn from the bottom up.

It would be logical that you also start your liquid fuel engine, as any engine not immediately started is dead weight (and usually better left at home). You did not tell us anywhere that you did not and only started your SRB's. Anyway, it still is a whole lot of push for a little craft, so that might very well be your problem. Be aware that the air with FAR is a lot less dense than with stock aerodynamics (just like in reality).

SRB's in reality burn equally all over, as they are tunnels of solid rocket fuel to optimise thrust. They are a little more advanced than fireworks. I am unsure how KSP models them, but I think it is not by shifting the CoM up.

[Vrana]

Solid rockets burn from the bottom up.

Nope. In reality they burn "inside out" so they should not be effecting the CoM. Not sure if this is what happens in KSP tough.

[Godot]

Don't solid rockets burn from the bottom up? The mass should be shifting up, not down. I can retain 100% liquid fuel in the center stack and the burning action of the SRBs causes the flip.

If the mass is shifting down as they burn, well, they're programmed wrong. That's either a bug in the base game or a bug in FAR.

I guess in KSP there is no weight distribution within a certain part ...

with other words, the Boosters only get lighter as a whole (without a shift in their weight balance).

However, under the assumption that your middle engine is active as well from the beginning on ...

your topmost fuel tank gets lighter and lighter (as the fuel for your rocket engine is taken from the top first)

and then (after the topmost fuel tank is empty) your middle fuel tank.

So, what Ralathon said is correct ... your weight distribution shifts to the lower part.

[Frostiken]

Fair enough.

I also forgot that we can throttle down SRBs now. I'll play with it.