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[0.90WIP] Procedural Parts - Parts the way you want 'em 0.9.21, Dec 19


swamp_ig

Would you prefer decouplers to:  

118 members have voted

  1. 1. Would you prefer decouplers to:

    • Closely as possible follow stock behaviour
      15
    • Have a sensible relation between size, decoupler force, and mass
      153


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I am not using realistic fuel.

If I make an exact copy of the space shuttle srb I get 3.75 meter diameter, 45.5 meters tall, and a max thrust of 7.031 mn or 7031 kn with 168 seconds of burn time at 87.5 tons but it bareeeeely lifts itself off.

On the other hand if I make a 1.25 meter diameter 10 meter tall srb I get 781 kn of thrust with 37.1 seconds of burn time at 15 tons and it takes off like a mofo.

These two rockets have roughly the same width to height ratio.

Due to how expanding spaces work the bigger one is 4 times bigger and weighs 6 times more.

However! The bigger one SAYS it has almost 10 times more thrust to weight but it sure as heck does not act like it.

Well firstly, If your not using the realism patch then it's not surprising that you can't make realistic rockets. Secondly, it's weighs 8 times more (2*2*2 = 8), which means you probably should have a twr of not that much more than one.

Also, the space shuttle SRB has a height/width ratio of 12.1, while your smaller booster has a height to weight ratio of 8, so they're pretty different.

Edited by OtherBarry
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I edited my post a bit because the mech jeb weight seemed to be off, using engineer weights and I refined the smaller rocket to be closer.

Even if I make the smaller booster 2 times taller it takes off much MUCH faster.

There is a problem there.

Edited by Spider0804
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I edited my post a bit because the mech jeb weight seemed to be off, using engineer weights and I refined the smaller rocket to be closer.

Even if I make the smaller booster 2 times taller it takes off much MUCH faster.

There is a problem there.

Huh. Install MechJeb or KER and have a look at the TWRs of the boosters. See if they're consistent between editor mode and flight mode, and see if they seem to scale properly as you change the size/thrust of your booster. "MUCH faster" isn't the most accurate form measurement.

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In the edited post I post the twrs and I confirmed this by launching them, the smaller one is easily 3 times faster with both having a maxed out nozzle.

The shuttle booster literally just barely lifts off the ground.

It takes a good 5 seconds to clear its own height.

I have both mechjeb and KER but mechjeb seems to derp when I change a srb size and not display the correct weight until I reload the craft or launch and come back.

KER on the other hand does update correctly so I used kg instead of tons.

That nozzle spawning on the top side of the shuttle srb bug sure is a weird one.

Edited by Spider0804
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In the edited post I post the twrs and I confirmed this by launching them, the smaller one is easily 3 times faster with both having a maxed out nozzle.

Right. Well, all the maths is legit, everything's scaling as it should. I think the problem is you want more thrust per meter of diameter than PP currently allows. This is because PP is designed to replicate stock parts, not real rockets. You can change this in the cfg file if you wish, but it won't go into the full release of the mod.

The weird nozzle spawning is a known bug, an being worked on at the moment. It might be fixed in the latest version, though obviously not if your using it now.

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0.9.12 is the version I am using, if I get it with 0.9.14 I will report back here.

Yes I wanted more thrust per meter because the thrust to weight ratio gets worse and worse with the same width to height ratio.

My only point was that the shuttle sized srb should have a twr of around 2 instead of 1.16.

Edited by Spider0804
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Yes I wanted more thrust per meter because the thrust to weight ratio gets worse and worse with the same width to height ratio.

Unfortunately, that's just the laws of physics. The thrust of an SRB, or more correctly the exhaust velocity, is controlled almost entirely by the diameter of the smallest part of the nozzle. The relationship between them has a power of two in it somewhere, while mass is a power of three, as it's directly related to volume. This means that means that keeping to the same diameter/height ratio will result in the mass rather quickly eclipsing the thrust as you increase the size.

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I get that but realistically no srb would ever have a thrust to weight ratio of under 1.5, the shuttle srb was massive and still held up at 2.

Maybe the equation could be tweaked to let the nozzles be bigger than the diameter like they are on the shuttle srb.

Anyway if that is not acceptable I will drop it, thankyou for talking about it though.

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I get that but realistically no srb would ever have a thrust to weight ratio of under 1.5, the shuttle srb was massive and still held up at 2.

Maybe the equation could be tweaked to let the nozzles be bigger than the diameter like they are on the shuttle srb.

Anyway if that is not acceptable I will drop it, thankyou for talking about it though.

You can tweak it easy enough. Have a look at this MM patch.

As OtherBarry has stated, the out of the box config will remain - we're trying to replicate KSP, not real rockets.

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Wishlist:

- Radial decouplers

- Flanged radial decouplers

- Flanged nose cones (think Ariane V boosters)

- Inflatable heatshield (think Deadly Reentry, but in procedural sizes)

...and lots more that I have thought of but cannot think of at the moment.

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Oh yes, and two things:

First, thanks for a great mod! KSP Stock is a good game. KSP modded with PP (and a few others, to be honest) is a great game!

Secondly, the decoupler behaves a little strange if you accidentally set the radius to zero. It's easy to do, just press the leftmost radius button once. What about a minimum radius of, say, 0.5?

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Secondly, the decoupler behaves a little strange if you accidentally set the radius to zero. It's easy to do, just press the leftmost radius button once. What about a minimum radius of, say, 0.5?

Thanks for your issue report, will fix.

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Alright, i have no idea what is happening.

i installed procedural parts may 19, and it didnt work. I didnt play ksp until now again. Whenever I right click a part, it just shows the fuel/oxidizer thing, no editing parts.

Is this a bug? Or do I have to reinstall?

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Alright, i have no idea what is happening.

i installed procedural parts may 19, and it didnt work. I didnt play ksp until now again. Whenever I right click a part, it just shows the fuel/oxidizer thing, no editing parts.

Is this a bug? Or do I have to reinstall?

Do you have multiple versions of the Module Manager dll?

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Is this a bug? Or do I have to reinstall?

Theres been at least 3 releases since may 19, so try the latest version and see if the issue persists. It's popped up a fair few times, so it may be a conflict of some kind if it's not fixed after updating.

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Another feature request, I might look into tackling this myself: the ability to alter the vectoring range of an SRB. How about if you want a wider range, it'll add weight? I know it's hard to implement an electrical usage for gimballing, but that would be interesting as well.

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I wanted a nose cone that doubled as a heatshield so I made the following edits to proceduralHeatshield:


@PART[proceduralHeatshield]
{
@MODULE[ProceduralPart]
{
@aspectMin = 1.5
!lengthMax = 0
!allowCurveTweaking = 0
}

@MODULE[TankContentSwitcher]
{
@TANK_TYPE_OPTION
{
@dryDensity = 0.12
}
}
}

It mostly works. The mass is slightly higher than a proceduralNoseCone, and the amount of ablative shielding is obscene but can be adjusted because of tweakables.

My biggest problem is that my giant SRB pushes my rocket too fast so most of my ablative shielding burned off during launch :(.

O2tjwjG.png

Note that the mass displayed for the nose cone is incorrect. It actually weights around 1.8t including the 1025 units of shielding.

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Theres been at least 3 releases since may 19, so try the latest version and see if the issue persists. It's popped up a fair few times, so it may be a conflict of some kind if it's not fixed after updating.

Reinstalled, its broken.

Mods-

Mechjeb

This

Novapunch

Procedural Fairings

Kethane

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Reinstalled, its broken.

Mods-

Mechjeb

This

Novapunch

Procedural Fairings

Kethane

Update Everything, Procedural Fairings uses a common dll with PP, so there could be a grinding wheel between the two.

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With Real Fuels installed, it looks like the RCS and Xenon tanks are hidden from the part list. We can't use normal liquid tanks for these resources because their dry masses are different.

EDIT: Though now that I've un-hidden them, it looks like I can't edit their contents, with RF 6.2

Edited by curiousepic
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With Real Fuels installed, it looks like the RCS and Xenon tanks are hidden from the part list. We can't use normal liquid tanks for these resources because their dry masses are different.

Yes, with RF and PP, the tanks are deleted. Why can't you use other tanks for RCS or Xenon?

EDIT: Though now that I've un-hidden them, it looks like I can't edit their contents, with RF 6.2

Correct, because the default tanks don't have RF capability installed.

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