ferram4

[1.3] Kerbal Joint Reinforcement v3.3.3 7/24/17

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@ANWRocketMan: What G-Forces are you hitting? You are using the decoupler stiffening option, right? Can you provide a craft? Go into the config.xml and change "debug" to 1, reproduce the issue and then post the log here.

It might just be that you're asking far too much of the joints; it's not like they're supposed to be indestructible, though they should fail long before that happens.

@Surefoot: That's an error that pops up with pretty much all landing gear; it's safe to ignore it.

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Ah, I see what's happening. Since the plugin can't load the mesh for whatever reason,(...)

Just looked at the log again: the warning i quoted above is happening before i see this: "ground contact!", "Unpacking (plane name)", "[Proceduralwing2]: Activated", etc. Are the procedural parts meshes loaded only upon activation maybe ?

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@ferram4: I'm pulling max about 2G's. I'll quickly quickly enabled debug mode. The decoupler stiffenening option is set to 1. So I assume that is on?

To be fair, that is a 65 ton payload though... But on another point, I once built a 180-ton payload launcher that worked fine(with KW Rocketry and FAR)... but that was in 0.18.4.

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@Surefoot: That might be something to look into. I'll try it out.

@ANWRocketMan: Yep that's activated... try increasing angularMaxForce to something unreasonable and see what happens. It might just be that the angular stiffness is being overloaded and it's falling apart that way.

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I guess you still have to be careful with AoA on ascent with a long rocket / top heavy load and sideways forces, which makes sense.

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@ferram4:

[LOG 23:28:24.732] Updated joint from 3.75m Stack Decoupler to KW Rocketry Wildcat-XR

Std. Joint Parameters

Connected Body: KW3mengineWildcarXR (UnityEngine.Rigidbody)

Anchor: (0.0, 0.0, 0.0)

Axis: (1.0, 0.0, 0.0)

Sec Axis: (0.0, 0.0, 1.0)

Break Force: 200

Break Torque: 200

Linear Drive

Position Spring: 11044.69

Position Damper: 441.7874

Max Force: 200000

Mode: PositionAndVelocity

Angular Drive

Position Spring: 174730.8

Position Damper: 2329.743

Max Force: 20000

Mode: PositionAndVelocity

Cross Section Properties

Radius: 2.651653

Area: 22.08937

Moment of Inertia: 38.82906

That's the log for the 3.75m decoupler. Most of the other joints seem to have 'Break force' and 'Break Torque' values of like 100000. I see their part.cfg files have those values. I'll try setting that up too, see if that fixes it.

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Break force and Break torque don't do anything to affect stiffness. Try increasing angularMaxForceFactor in the config.xml file, which will increase the max force that the angular drive setting can output. That will likely help.

How do the drive settings compare between the decoupler and the other KW parts?

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I have to agree with @spudcosmic!

I'll do some more testing and get back to you tomorrow. I have to get to bed. Not even Jeb himself could keep a mere mortal such as myself from my sleep.

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You sir just fixed the biggest problem that the very basic concept of KSP has standing in it's way.

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Both of these rockets would have lost their nozzles within a few seconds of start up before this mod.

180 ton rocket with SRB producing 2.3 kN of thrust (through 5 fuel segments) flies impeccably

B28fg8vl.png

280 ton rocket with SRB producing 4.9 kN of thrust (through 8 fuel segments) flies not so great. Same rocket with 4 2x size segments is working great.

RcQZIBLl.png

Thanks Ferram!

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Just a little something I've noticed but I've always avoided the KW decouplers because they always caused issues with flexing and breaking where using a stock decoupler would behave fine.

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Break force and Break torque don't do anything to affect stiffness. Try increasing angularMaxForceFactor in the config.xml file, which will increase the max force that the angular drive setting can output. That will likely help.

How do the drive settings compare between the decoupler and the other KW parts?

What do the angularMaxForceFactor and the linearMaxForceFactor effect?

I boosted both and something magic seemed to happen.

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They control the maximum force that the "drives" can apply; the drives are essentially spring-damper combos that keep the parts where they should be, linear controlling how far it can move in any direction, angular controlling how much it can twist.

The max force would be set to infinity, but then if the simulation hiccups or you're dealing with a particularly large rocket on load the force can become incredibly large and tear the rocket apart, so I set it slightly low. I'm thinking I should have set it higher by default now.

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They control the maximum force that the "drives" can apply; the drives are essentially spring-damper combos that keep the parts where they should be, linear controlling how far it can move in any direction, angular controlling how much it can twist.

The max force would be set to infinity, but then if the simulation hiccups or you're dealing with a particularly large rocket on load the force can become incredibly large and tear the rocket apart, so I set it slightly low. I'm thinking I should have set it higher by default now.

I added a zero to both and now my 11m diameter test monstrosity ( Jeb is in love) can get to orbit.

Before it would either spin to it's ass or the bottom engines would fall off, or the top part would fall off the booster.

It seems pretty hard to make realistic-ish bottom heavy rockets in ksp.

I'm thinking Saturn V had 2300t in first stage of 2800t. Try that in ksp :D

Edited by p3asant

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OK then, the next release will have both increased by a factor of 10.

The real issue in KSP with building these gigantic rockets is that you're connecting a massive tank (100 tons) to a decoupler (1 ton) to an engine (10 tons) to another massive tank (50 tons) and such disparate masses connected together plays havoc with rigid body physics simulations. On the other hand, connecting lighter tanks to the decoupler and engine combo results in more joints closer together, which leads to more opportunities for flexing. It's kind of a terrible situation all around, and it would be better if we could choose to apply a decoupler PartModule to the top of a fuel tank, and then directly attach the tank to the engine, and not bother with the separate lightweight and problematic decoupler part. But that would probably be confusing for players, new and old.

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OK then, the next release will have both increased by a factor of 10.

The real issue in KSP with building these gigantic rockets is that you're connecting a massive tank (100 tons) to a decoupler (1 ton) to an engine (10 tons) to another massive tank (50 tons) and such disparate masses connected together plays havoc with rigid body physics simulations. On the other hand, connecting lighter tanks to the decoupler and engine combo results in more joints closer together, which leads to more opportunities for flexing. It's kind of a terrible situation all around, and it would be better if we could choose to apply a decoupler PartModule to the top of a fuel tank, and then directly attach the tank to the engine, and not bother with the separate lightweight and problematic decoupler part. But that would probably be confusing for players, new and old.

Afaik there already are upper stages which function as engines tanks and decouplers at the same time.

It would be kinda cool to have an stretchable, universal part which includes tank,engine and decoupler.

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and it would be better if we could choose to apply a decoupler PartModule to the top of a fuel tank, and then directly attach the tank to the engine, and not bother with the separate lightweight and problematic decoupler part.

I say: welding!

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Wow, this looks great Ferram!

But I have a concern. I glanced through the source and noticed a few places where it's multiplying existing parts breakingForce & breakingTorque

My concern is that a lot of parts do not define breakingForce OR breakingTorque in their part config files. Surprisingly, the main offender is Squad themselves. Several engines (*cough*nuclear*cough*) and pretty much all probe and command pods.

I didn't look through the entire source, so apologies if this is already done in there somewhere, but could you check parts to see if those properties are absent and set them first instead of just 'breakingForce *= 1000'

Or do you know if those properties have a non-zero default value? (which would probably make this a non-relevant point)

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Or do you know if those properties have a non-zero default value? (which would probably make this a non-relevant point)

My understanding was that the default value is 20, but I can't find a source for that now, so consider that hear-say...

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I have thought about adding decoupler modules to engines, just setting the decouple node to bottom. That way when you press space, it'll decouple the tank and activate the engine at the same time.

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@StarWaster: The only time "breakForce *= 1000" is called is for launch clamps; otherwise it changes nothing about the default breakForce or breakTorque other than to multiply by universal constants, which are set to 1 by default.

In the other situations if a breakForce or BreakTorque was equal to zero the parts would separate instantly, because it would mean that the part joints could not take any force before failing, so I'm fairly certain it is non-zero.

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My understanding was that the default value is 20, but I can't find a source for that now, so consider that hear-say...

Problem is that you would think that any non-zero value would show up in the debug page for those parts. I'll check that again after installing this mod. I'll also try taking a ship into deep space with this mod running. With a nuclear engine on it unstrutted. (They tend to fall off spontaneously. Even on stationary ships)

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@StarWaster: The only time "breakForce *= 1000" is called is for launch clamps; otherwise it changes nothing about the default breakForce or breakTorque other than to multiply by universal constants, which are set to 1 by default.

In the other situations if a breakForce or BreakTorque was equal to zero the parts would separate instantly, because it would mean that the part joints could not take any force before failing, so I'm fairly certain it is non-zero.

Ok thx for the reply

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