Just ullage and nerfed reaction wheels?

[Joontry]

Hi,

I'm interested in just adding ullage requirements and nerfing reaction wheels in a KSP 1.12.2 JNSQ career save. Is there a relatively easy way to do this without getting the full realism overhaul? Thanks

[RKunze]

For ullage (and of course engine ignition limits), there is Engine Igniter Reignited. 

Nerfing reaction wheels can be done with a simple ModuleManager patch that has been floating around the forums. Here is the version I am currently using in JNSQ:

// Nerf the overpowered stock reaction wheels
//
// first pass, *all* reaction wheels to 0.25 = 25%
@PART[*]:HAS[@MODULE[ModuleReactionWheel]]{
  @MODULE[ModuleReactionWheel]{
    @PitchTorque *= 0.25
    @YawTorque *= 0.25
    @RollTorque *= 0.25
  }
}
// second pass, non-dedicated parts to 0.25*0.04 = 1%
@PART[*]:HAS[@MODULE[ModuleReactionWheel],@MODULE[ModuleCommand]]{
  @MODULE[ModuleReactionWheel]{
    @PitchTorque *= 0.04
    @YawTorque *= 0.04
    @RollTorque *= 0.04
  }
}
// finally, (airplane) cockpits usually don't have reaction wheels at all
// create exceptions for non-airplanes if/when necessary
@PART[*ockpit*]:HAS[@MODULE[ModuleReactionWheel]]:FINAL{
  -MODULE[ModuleReactionWheel]{}
}

[CobaltWolf]

21 hours ago, Joontry said:

Hi,

I'm interested in just adding ullage requirements and nerfing reaction wheels in a KSP 1.12.2 JNSQ career save. Is there a relatively easy way to do this without getting the full realism overhaul? Thanks

I use the Engine Ignitor, Mandatory RCS and Persistent Rotation to achieve exactly that.

[Joontry]

Thanks for the replies and advice! I'll try these out but hopefully them not being listed as compatible with 1.12.2 won't be a deal breaker. I've never written my own config patch but I guess I just make a notepad document with that text copied and pasted and save is as a .cfg in the game data folder. I'm not sure exactly what purpose Persistent Rotation would serve for achieving my goals here, as I already have Principia installed. Can I ask why Persistent Rotation was recommended?

[evileye.x]

On 11/22/2021 at 6:37 AM, RKunze said:

For ullage (and of course engine ignition limits), there is Engine Igniter Reignited. 

Nerfing reaction wheels can be done with a simple ModuleManager patch that has been floating around the forums. Here is the version I am currently using in JNSQ:

I just remove RW module from all non-dedicated parts and make all reaction wheels  weaker (1%), far more expensive (5x) and evergy consuming (10x).

The only exception - parts that have intake air like Airplane Plus helicopter rotors - to emulate cyclic control on those. 

I use Engine Ignitor and Persistant Rotation as well.

Spoiler

@PART[*]:HAS[#CrewCapacity[>-1],@MODULE[ModuleReactionWheel]]
{
	!MODULE[ModuleReactionWheel]
	{
//	!name = ModuleReactionWheel = Delete
	}
}

@PART[*]:HAS[@MODULE[ModuleReactionWheel],!RESOURCE[IntakeAir]]:FINAL
{
  @MODULE[ModuleReactionWheel]
  {
    @PitchTorque *= 0.01
    @YawTorque *= 0.01
    @RollTorque *= 0.01
	@RESOURCE[ElectricCharge]
    {
        @rate *= 10.0 // Change by how much you want the EC usage multiplied 
    }
  }
  @cost *= 5
}

 

On 11/23/2021 at 7:52 AM, Joontry said:

Thanks for the replies and advice! I'll try these out but hopefully them not being listed as compatible with 1.12.2 won't be a deal breaker. I've never written my own config patch but I guess I just make a notepad document with that text copied and pasted and save is as a .cfg in the game data folder. I'm not sure exactly what purpose Persistent Rotation would serve for achieving my goals here, as I already have Principia installed. Can I ask why Persistent Rotation was recommended?

Because otherwise you just warp and it kills your angle momentum completely. May Principia fixes that, I don't know.

[Joontry]

Thanks for sharing your patch, evileye.x. Based on a very small sample size (N=4 or 5) of real control moment gyroscopes (CMGs) and a sample of ten real reaction wheels currently available on satsearch.co, I estimate that real CMGs produce an average of 1.14913 newton meters of torque per kilogram (of CMG), while real reaction wheels produce an average of 0.031358 newton meters of torque per kilogram (of reaction wheel). Meanwhile, stock KSP reaction wheels produce 100 to 150 newton meters of torque per kilogram. So assuming stock rx wheels average 125Nm/kg, to bring them down to real life CMG strength you'd nerf by a factor of 0.00919304, to bring them to the average of real CMGs and real reaction wheels (0.590244 Nm/kg), you'd nerf it by a factor of 0.004721952, and to bring them down to the strength of just real reaction wheels you'd nerf by a factor of 0.000250864. Obviously these are just approximations based on a bit of googling and spreadsheeting, and don't account for size or electric power usage, but they should be in the ballpark.

It would be cool if a patch could distinguish between the CMG's that come with some mods and the reaction wheels, but I have no idea how to do that. I wanted to include the ISS' CMG in my calculation but couldn't find its mass anywhere. If someone knows it please let me know.

TLDR, I think KSP reaction wheels are about 108 times stronger than real life control moment gyroscopes, and about 3,986 times stronger that real life reaction wheels.