I want to learn how to make simple modded parts.

[WhiteWeasel]

Ok, I want to learn the basics of modding ksp. I'm somewhat familiar with coding, but not a whole lot. So It would be nice for someone to instruct me on how to make an alternate version of an existing part to start off easy. Let's take the ION engine for example. Alot of it is just changing numbers but still. And yes my save is backed up.

My goals

1)Make a copy of the ION engine (So I don't change the original)

2)Retitle copy to MLAS Adv. ION Thruster

3)Change thrust to .75 kN (50% increase)

4)Change mass to .30 (20% increase)

5)Change e/s from 14.442 to 17.331 (20% increase)

6)Make the blue "thrust" purple*

*Probably not done in the code I think. Don't want to worry about textures just yet.

Edited December 21, 2013 by WhiteWeasel

[WhiteWeasel]

Anybody? I'd really like to learn over christmas break.

[Galacticruler]

only #6 is difficult, because you need to know Unity to edit that.

the others are all in the part config, whch can be edited using Notepad or any other text editor.

[WhiteWeasel]

What folder is ksps code in?

[astropapi1]

KSP_Win.

[WhiteWeasel]

which folder & file in KSP_WIN?

[Fiddlestyx]

Every thing you need is at Kerbal Space Program\GameData\Squad\Parts\Engine\ionEngine.

You want to edit the "part" CFG file.

You need to make a copy of the "ionEngine" folder and rename it to what you want. Also, don't forget to rename the "name = ionEngine" in the new part file, it needs to exactly match the name of the new folder.

Look here for more help http://wiki.kerbalspaceprogram.com/wiki/CFG_File_Documentation

[WhiteWeasel]

Hmm, I don't see power consumption anywhere.

PART
{
name = MLAS Adv. Ion Drive
module = Part
author = NovaSilisko

mesh = model.mu
scale = 1
rescaleFactor = 1

node_stack_top = 0.0, 0.2135562, 0.0, 0.0, 1.0, 0.0, 1
node_stack_bottom = 0.0, -0.1872844, 0.0, 0.0, 1.0, 0.0, 1

TechRequired = ionPropulsion
entryCost = 16800
cost = 5700
category = Utility
subcategory = 0
title = MLAS Adv. Ion Drive
manufacturer = Musteline Aerospace
description = Identical in structure to the PB-ION Electric Propulsion System, but internal circuts and and grid have been retofitted with more powerful, but costly replacements. Overall improvement to thrust, but higher weight and power consumtion as well. 
attachRules = 1,0,1,1,0

// --- standard part parameters ---
mass = 0.30
dragModelType = default
maximum_drag = 0.2
minimum_drag = 0.2
angularDrag = 2
crashTolerance = 7
maxTemp = 3600

MODULE
{
	name = ModuleEngines
	thrustVectorTransformName = thrustTransform
	exhaustDamage = False
	ignitionThreshold = 0.1
	minThrust = 0
	maxThrust = 0.75
	heatProduction = 0
	PROPELLANT
	{
		name = ElectricCharge
       		ratio = 12.0
	}
	PROPELLANT
	{
		name = XenonGas
		ratio = 0.1
	}
	atmosphereCurve
 	{
   	 key = 0 4200
 	}

}

MODULE
{
      name = FXModuleAnimateThrottle
      animationName = colorAnimation
      dependOnEngineState = True
      responseSpeed = 0.5
}

}

[Skyler4856]

http://unity3d.com/learn/tutorials/modules/beginner/scripting

Have fun!

[WhiteWeasel]

	name = ElectricCharge
       		ratio = 12.0

Would changing this in some way get me the desired effect?

[Clockwork_werewolf]

Simple answer, sort of.

The Fuel use of an engine is based on three things, the thrust, the ISP and the fuel ratio.

The thrust changes the fuel use and changing maxThrust would change the fuel use per second at full power but not its efficiency.

Changing ElectricCharge ratio = 12.0 to a smaller ammount would mean it used less electric but MORE Xenon, the ratios of fuel here just changes there ratio of use not the engines ISP.

ISP or fuel use per thrust is defined by "atmosphereCurve key = 0 4200" this means at level 0 (and all other because no other are defined) the ISP is 4200 (really good).

If you want the engine to be less efficient change the atmocurve.

If you want the engine to use more fuel because it produces more thrust change maxThrust.

If you want the engine to use more Xenon and less electricicty then change the ratio numbers.

I can't tell if you want to change the engines ISP AND fuel ratio or just use more fuel as it is a stronger engine but using the same ISP.

[WhiteWeasel]

So the resources are not independent? It, might be a lot harder to keep ISP & fuel consumption the same and only increase thrust and e consumption than I thought. I might have to rethink what I'm going to change.

Overall my goal is to increase thrust, but make it consume more resources. Kinda of a side grade because it's more powerful, but weighs and needs more power, making it less useful for small craft. But since large (relatively) craft already have lot of peripherals the extra weight won't matter as much.

EDIT: Hmmm, the effect is more desired than I thought. Maybe I should drop the ISP for balance?

Normal drives:

My drives:

Edited December 22, 2013 by WhiteWeasel

[NathanKell]

Fuel units consumed per second by engine:

let mass_sum = total mass of all propellants in ratio form (sum, over all PROPELLANT, of ratio * density of each)

let desired_mass = thrust / Isp / 9.82

for each resource, consume desired_mass / mass_sum * ratio

Note that this means that changing the ratio of a massless resource (i.e. ElectricCharge) or the only massed resource (XenonGas, when the only other resource is ElectricCharge) has no effect on actual rate of consumption of the massed resource. What it does do is change how much the massless one(s) are consumed.

Example

Xenon 1, EC 15

is the same as

Xenon 2 EC 30

Both will result in Xenon and EC being consumed the same amount.

Note however that

Xenon 1 EC 30

and

Xenon 0.5 EC 15

will both result in a doubling of EC consumption from Xenon 1 EC 15.

======

If you want to keep XenonGas usage constant, you will need to change Isp in proportion to changing thrust. If you want to do that AND up electric usage, you should up Isp in proportion to changed thrust AND increase the ratio under ElectricCharge

[WhiteWeasel]

Would this work?

PROPELLANT
	{
		name = ElectricCharge
       		ratio = 16.0
	}
	PROPELLANT
	{
		name = XenonGas
		ratio = 0.1
	}
	atmosphereCurve
 	{
   	 key = 0 6300
 	}

Ec increased by 30%

Isp increased by 50% along with thrust

[NathanKell]

yep, that should do it.